Wrocław University of Technology Nicolaus Copernicus University, Toruń

PROCEEDINGS

OF THE XXII nd INTERNATIONAL SYMPOSIUM

ON PHYSICOCHEMICAL METHODS OF SEPARATIONS

“A RS SEPARATORIA 2007”

JUNE 10-14, 2007, SZKLARSKA PORĘBA, POLAND

2007

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EDITORS

Andrzej W. Trochimczuk Władysław Walkowiak

REVIEWERS

Wiesław Apostoluk Marek Bryjak

Andrzej Kołtuniewicz Gryzelda Poźniak

Andrzej W. Trochimczuk Władysław Walkowiak

PREPARATION FOR PRINTING

Anna Jakubiak Magdalena Pilśniak

Andrzej W. Trochimczuk

© No part of this publication may be reproduced in any form by print, photoprint, microfilm or any other means without permission from the

publisher

ISBN 978-83-7493-317-9

WROCŁAW UNIVERSITY OF TECHNOLOGY NICOLAUS COPERNICUS UNIVERSITY, TORUŃ

WROCŁAW – TORUŃ, 2007

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XXII ND

INTERNATIONAL SYMPOSIUM ON PHYSICOCHEMICAL METHODS

OF SEPARATIONS

“Ars Separatoria 2007”

SZKLARSKA PORĘBA

POLAND JUNE 10-14, 2007

organized by:

Faculty of Chemistry

Wrocław University of Technology

Department of Chemistry Nicolaus Copernicus University, Toruń

INTERNATIONAL ADVISORY BOARD

Prof. B. Buszewski, Poland Prof. W. Charewicz, Poland Prof. G. Cote, France Prof. K. Inoue, Japan Prof. A. Narębska, Poland Prof. A.M. Sastre, Spain Prof. S. Schlosser, Slovakia Prof. S. Siekierski, Poland Prof. M. Streat, UK Prof. G. Sulaberidze, Russia Prof. W. Wójcik, Poland

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Prof. Beniamin Lenarcik - Honorary Chairman

ORGANIZING COMMITTEE

Dr hab. Andrzej W. Trochimczuk - chairman Prof. Władysław Walkowiak - co-chairman Dr Dorota Jermakowicz-Bartkowiak - secretary Dr ElŜbieta Radzymińska-Lenarcik Ms. Anna Jakubiak, M.Sc. Ms. Magdalena Pilśniak, M.Sc. Ms. Sylwia Ronka, M.Sc.

Address: Faculty of Chemistry

Wrocław University of Technology Wyspiańskiego 27

50-370 Wrocław, Poland Phone: (048) 71 320-3173 Fax: (048) 71 320-2987

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I. LECTURES

L-1 Gérard Cote and Alexandre Chagnes 14 SOLVENT EXTRACTION IN HYDROMETALLURGY: PRAGMATISM AND SCIENCE

L-2 Rosa Maria Marcé, Núria Fontanals, Francesc Borrull 16

TRENDS IN SORBENTS FOR SOLID PHASE EXTRACTION L-3 Spiro D. Alexandratos 20

ION-COORDINATING POLYMER-SUPPORTED REAGENTS: SYNTHESES AND SELECTIVITIES

L-4 Kazuya Uezu 24

SURFACE-TEMPLATED POLYMERS FOR REMOVAL OF FLUORIDE IONS

L-5 Nalan Kabay 29

APPLICATIONS OF ION EXCHANGE RESINS FOR ENVIRONMENTAL CLEAN-UP

L-6 Ecaterina Stela Dragan, Maria Valentina Dinu, 31

Ecateriana Avram ORGANIC ION EXCHANGERS. SYNTHESES AND CHARACTERIZATION

L-7 Andrzej Kołtuniewicz 32

SEPARATION PROCESSES WITH MEMBRANE BASED HYBRYD PROCESSES

L-8 Marek Bryjak 39

PLASMA MODIFIED POLYMER MEMBRANES L-9 Paweł Pluciński 42

FUNCTIONALIZED MAGNETIC FLUIDS FOR SEPARATION AND TARGETED DELIVERY

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II. SHORT LECTURES

S-1 Waldemar Robak, Wiesław Apostoluk, Barbara Wodniak 44 ANALYSIS OF LIQUID-LIQUID DISTRIBUTION CONSTANTSOF 8-HYDROXYQUINOLINE AND ITS DERIVATIVES

S-2 Barbara Marszałkowska, Magdalena Regel-Rosocka, 52 Maciej Wi śniewski PHOSPHONIUM IONIC LIQUIDS AS AN EXTRACTANT OF ZINC

FROM HYDROCHLORIC AMID SOLUTIONS S-3 Wanda Śliwa, Cezary A. Kozlowski, Tomasz Girek, 56

Wladyslaw Walkowiak THE EFFECT OF β-CD DERIVATIVES STRUCTURE ON THE REMOVAL OF COPPER(II) IN ION FLOTATION PROCESS

S-4 Alexandre Chagnes, Gérard Cote, Bruno Courtaud, 58

Jacques Thiry KINETIC ASPECTS OF THE DEGRADATION OF SOLVENTS IN HYDROMETALLURGICAL LIQUID-LIQUID PROCESSES

S-5 Barbara Wionczyk 60

DEPENDENCE OF CHROMIUM(III) EXTRACTION FROM ALKALINE SOLUTIONS ON TEMPERATURE

S-6 Andrzej W. Trochimczuk 65

CROSSLINKED IMIDAZOLIUM-TYPE IONIC LIQUIDS AND THEIR EXTRACTIVE PROPERTIES

S-7 Dilek Duranoğlu Gülbayir , Ülker Beker 69

REMOVAL OF CHROMIUM (VI) FROM AQUEOUS SOLUTION BY LOW COST ADSORBENT

S-8 Murat Semiha, Dilek Duranoğlu Gülbayir, Ülker Beker 72

REMOVAL OF NICKEL FROM AQUEOUS SOLUTION BY USING FIXED BED ION EXCHANGE COLUMN

S-9 Jerzy Gęga 76

EXTRACTION OF METAL CATIONS WITH CALIX-CROWNS S-10 Dorota Kołodyńska, Halina Hubicka, Zbigniew Hubicki 79

SORPTION OF HEAVY METAL IONS FROM AQUEOUS SOLUTIONS IN THE PRESENCE OF COMPLEXING AGENTS ON POLYACRYLATE ANION EXCHANGERS

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S-11 Iain Roche, Danish J. Malik, Graham L. Warwick, 84 Nicolas A. Hoenich et al. A POROUS STYRENE DIVINYLBENZENE COPOLYMER ADSORBENT CAPABLE OF REMOVING MIDDLE MOLECULAR WEIGHT MOLECULES FROM BLOOD WHILST SIZE EXCLUDING ALBUMIN

S-12 Chris Webb, Danish J. Malik, Richard G. Holdich 88

ENGINEERING OF THE INTERNAL PORE STRUCTURE OF POLY(STYRENE-DIVINYLBENZENE) ADSORBENTS FOR THE REMOVAL OF MIDDLE MOLECULAR WEIGHT PROTEINS FROM BLOOD AND THE EXCLUSION OF ALBUMIN

S-13 Rajmund S. Dybczyński, Z. Samczyński, E. Chajduk, 93

B. Danko, H. Polkowska-Motrenko ION EXCHANGE AND EXTRACTION CHROMATOGRAPHY AS A BASIS OF SEPARATION SCHEMES FOR EFFICIENT SEPARATION AND DETERMINATION OF SEVERAL ELEMENTS BY NAA AND OTHER TECHNIQUES

S-14 Luděk Jelínek, Yuezhou Wei, Tsuyoshi Arai 95

VALENCE CONTROL IN LANTHANIDE SEPARATION VIA SORPTION TECHNIQUES

S-15 Monika Leszczyńska, Zbigniew Hubicki 98

APPLICATION OF WEAKLY AND STRONGLY BASIC ANION EXCHANGERS FOR THE REMOVAL OF SULPHONATED AZO DYE

III. POSTERS P-1 Zbigniew Adamski, Aleksandra Kotecka, 104

Katarzyna Rotuska, Wiesław Apostoluk, Barbara Wionczyk,Witold Charewicz RECOVERY OF COLLAGEN HYDROLYSATE, CR(III) AND OTHER METALS FROM LIQUID AND SOLID INDUSTRIAL WASTES

P-2 Dorota Jermakowicz-Bartkowiak, BoŜena N. Kolarz 106

RHENIUM RECOVERY FROM ACIDIC SOLUTION ON FUNCTIONALIZED RESINS

P-3 Bernadeta Gajda, Mariusz B. Bogacki 107

LABORATORY SIMULATION OF NICKEL(II), COBALT(II) AND CADMIUM(II) IONS SEPARATION IN A CONTINUOUS COUNTER – CURRENT EXTRACTOR

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P-4 BoŜena Danko, Rajmund Dybczyński, 108 Zbigniew Samczyński CONTRIBUTION OF SEPARATION METHODS TO NAA OF MOLYBDENUM AND LANTHANIDES IN THE MATERIALS OF BIOLOGICAL ORIGIN

P-5 M. Valentina Dinu, M. Murat Ozmen, E. Stela Dragan, 109

Oguz Okay FAST RESPONSIVE MACROPOROUS HYDROGELS

P-6 Ecaterina Stela Dragan, Maria Valentina Dinu, 111

Cristina Doina Vlad LINEAR AND CROSSLINKED WEAK POLYELECTROLYTES CONTAINING PRIMARY AMINE GROUPS

P-7 Irena Gancarz, Gryzelda Poźniak, Jolanta Bryjak, 112

Marek Bryjak , Jerzy Kunicki PLASMA MODIFICATION OF POLYMER MEMBRANES

P-8 Agnieszka Gładysz-Płaska, Marek Majdan 121

ADSORPTION OF LANTHANIDES ON Na-MORDENITE P-9 Anna Jakubiak, BoŜena N. Kolarz 124

PROPERTIES OF Cu(II) IONS COORDINATED BY MOLECULAR IMPRINTED POLYMERS WITH AMINOGUANIDYL LIGANDS INSIDE THE IMPRINTS

P-10 A. F. Krivoschepov, V. V. Nazarov, K. I. Kienskaya, 127

V. Yarovaya, S. E. Muchtarova Ag - NANOPARTICLES IN COSMETIC COMPOSITIONS

P-11 Józef Drabowicz, Marcin Kłos 129

CLASSICAL AND NONCLASSICAL PROCEDURES FOR THE RESOLUTION OF RACEMIC 1-(PYRIDIN-2-YL)ETHYLAMINE

P-12 Dorota Kołodyńska, Halina Hubicka, Zbigniew Hubicki 131

CHELATING ION EXCHANGERS IN THE SORPTION OF COPPER(II) COMPLEXES WITH ETHYLENEDIAMINETETRAACETIC ACID

P-13 Cezary A. Kozłowski, Jolanta Kozłowska, 135

Władysław Walkowiak, Jacek Kozioł, Iwona Sergiel BIS-PNP-16-CROWN-6 DERIVATIVES AS ION CARRIERS FOR PB(II), ZN(II), AND CD(II) TRANSPORT ACROSS TRIACETATE CELLULOSE PLASTICIZED MEMBRANES

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P-14 I. M. Kurchatov , N. I. Laguntsov, V. N. Tronin, 137 V. I. Uvarov USING THE “WHITE NOISE” MODEL FOR DESCRIPTION GAS PERMEABILITY THROUGH THE COMPOSITE MEMRANES

P-15 A. Yu. Okunev, N. I. Laguntsov, I. M. Kurchatov 139

FUNDAMENTAL SEPARATION PROPERTIES OF MEMBRANE CONTACTOR SYSTEMS

P-16 ElŜbieta Radzymińska-Lenarcik, Beniamin Lenarcik 142

THE INFLUENCE OF STERIC EFFECT AND ALKYL CHAIN LENGTH ON FORMATION CU(II) COMPLEXES WITH 1-ALKYL-2-HEXYLIMIDAZOLE

P-17 ElŜbieta Radzymińska-Lenarcik, Beniamin Lenarcik 145

SOLVENT EXTRACTION OF CU(II) COMPLEXES WITH 1-ALKYL-1,2,4-TRIAZOLE

P-18 Marek Majdan , Oksana Maryuk, 147

Agnieszka Gładysz-Płaska, Paweł Sadowski ADSORPTIVE PROPERTIES OF THE CHABAZITE MODIFIED BY HEXADECYLTRIMETHYLAMMONIUM BROMIDE

P-19 Eva Mištová, Martina Telecká, Helena Parschová, 150 Luděk Jelínek, Ferdinand Šebesta SELECTIVE SORPTION OF ANTIMONY OXOANIONS BY COMPOSITE SORBENTS WITH HYDROUS OXIDES OF CERIUM AND ZIRCONIUM

P-20 Violeta Neagu, I. Plesca, Nalan Kabay, M. Yuksel 152

SORPTION STUDIES FOR SOME HEAVY METALS BY ACRYLIC CHELATING RESINS

P-21 V. V. Parashchuk, A. V. Volkov, Yu. P. Kuznetsov, 153

S. V. Kononova, D. V. Dmitriev, L. I. Trusov, V. V. Volkov NOVEL ASYMMETRIC MEMBRANES BASED ON POLYAMIDEIMIDE FOR ORGANIC SOLVENT NANOFILTRATION

P-22 Helena Parschová, Zdeněk Matějka, Eva Mištová 154

SORPTION AND SEPARATION OF HEAVY METALS FROM ETHYLENEAMINE COMPLEXES

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P-23 Karolina Klonowska-Wieszczycka, Andrzej Olszanowski, 158 Anna Parus, Barbara Zydorczak THE SOLVENT EXTRACTION OF COPPER (II) FROM CHLORIDE SOLUTION BY OXIME OF HYDROPHOBIC 2- AND 4-PYRIDYL KETONE

P-24 Karolina Klonowska-Wieszczycka, Andrzej Olszanowski, 159

Anna Parus THE SOLVENT EXTRACTION OF ZINC(II) AND CADMIUM (II) FROM CHORIDE SOLUTION BY OXIME OF HYDROPHOBIC 2-PYRIDYL KETONE

P-25 Magdalena Pilśniak, Andrzej W. Trochimczuk, 160 Wiesław Apostoluk GOLD (I) UPTAKE BY FUNCTIONALISED VINYLBENZYL CHLORIDE-DIVINYLBENZENE COPOLYMER BEARING AMINO GROUPS

P-26 Gryzelda Poźniak 162

WATER SOFTENING BY DONNAN DIALYSIS USING INTERPOLYMER AND HOMOGENEOUS CATION-EXCHANGE MEMBRANES

P-27 Gryzelda Poźniak, Ryszard Poźniak, Adam Sokołowski, 167

Marek Bryjak POLYETHERSULFONE MEMBRANES MODIFIED BY SURFACTANTS IN ULTRAFILTRATION AND MICELLAR ENHANCED ULTRAFILTRATION PROCESSES

P-28 Katarzyna Rotuska 174

CHROMIUM(III) MEDIATED TRANSPORT IN THE BULK LIQUID MEMBRANE SYSTEMS

P-29 Aleksandra Rybak, Zbigniew J. Grzywna 177

THE AIR SEPARATION THROUGH POLYMER AND “MAGNETIC” MEMBRANES

P-30 Andrzej Skrzypczak, Jan Błaszczak, 179

Jadwiga Zabielska-Matejuk ANION-EXCHANGE IN GEMINAL DICATIONIC IMIDAZOLIUM IONIC LIQUIDS

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P-31 Andrzej Skrzypczak, Jan Błaszczak, 180 Jadwiga Zabielska-Matejuk ANION-EXCHANGE OF DICATIONIC QUATERNARY AMMONIUM CHLORIDES

P-32 Andrzej Skrzypczak 181 INFLUENCE OF IONIC LIQUIDS ANION–EXCHANGE ON MENSCHUTKIN REACTION RATE CONSTANT

P-33 Georgy A. Sulaberidze, Valentine D. Borisevich, 182 Yuriy V. Litvin NEW APPROACH TO OPTIMIZATION OF THE Q-CASCADES

P-34 Piotr Szczepański 186

EFFECT OF ORGANIC SOLVENT ON THE PERTRACTION OF Zn(II) AND Cu(II) CATIONS IN BLM CONTAINING D2EHPA AS A CARRIER

P-35 Jolanta Szlachta, Jan Kalembkiewicz 188

STUDIES ON THE PHYSICAL CHEMISTRY OF (4-CHLORO-2-METHYLPHENOXY)ACETIC ACID IN TWO-PHASE SYSTEM: N-ALIPHATIC ALCOHOL - WATER

P-36 Wojciech Zapała, Lidia Zapała, Jolanta Szlachta 190

RETENTION BEHAVIOUR OF SELECTED FLAVONOIDS IN RP-HPLC SYSTEMS WITH CHEMICALLY MODIFIED ADSORBENTS

P-37 Lidia Zapała, Jolanta Szlachta, Jan Kalembkiewicz, 193

Wojciech Zapała IONIZATION AND PARTITIONING PROFILES OF 2-METHYLAMINOBENZOIC ACID

P-38 GraŜyna Szczepańska, Romuald Wódzki 195 BOND-GRAPH DESCRIPTION AND SIMULATION OF MEMBRANE PROCESSES. 1. DONNAN DIALYSIS

P-39 GraŜyna Szczepańska, Romuald Wódzki 197

BOND-GRAPH DESCRIPRION AND SIMULATION OF MEMBRANE PROCESSES. 2. MEBRANE EXTRACTION

P-40 Joanna Wolska, Marek Bryjak, Nalan Kabay 199 POLYMER MICROSPHERES WITH N-METHYL-D-GLUCAMINE FOR BORON REMOVAL FROM AQUEOUS SOLUTIONS

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P-41 Barbara Woźniak, Wiesław Apostoluk, Jerzy Wódka 203 SORPTION PROPERTIES OF TITANUM(IV) AND ZIRCONIUM(IV) MONOHYDROGENPHOSPHATES(V) AND THEIR MODIFIED DERIVATIVES TOWARDS DIAMMINE COMPLEX OF GOLD(I)

P-42 O. V. Yarovaya, N. N. Gavrilova, O. V. Zhilina, 206

K. I. Kienskaya, V. V. Nazarov SUPPORTED CuO-CERAMIC MEMBRANES FOR CATALYTIC APPLICATIONS

P-43 V. M. Zhdanov, V. I. Roldughin 208

SEPARATION OF GAS MIXTURE FLOWING IN NANOSIZE CAPILLARIES

P-44 Anna. Cieszyńska, Magdalena Regel-Rosocka, Maciej Wiśniewski EXTRACTION OF PALLADIUM(II) IONS FROM CHLORIDE SOLUTIONS WITH PHOSPHONIUM IONIC LIQUID CYPHOS®IL104 210

P-45 Sylwia Ronka, Andrzej W. Trochimczuk THE UPTAKE OF PHENOLS AND ANILINES FROM AQUEOUS SOLUTIONS BY THE POLYMER-DERIVED CARBON MATERIALS 213

AUTHORS INDEX 215

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I. LECTURES

14

SOLVENT EXTRACTION IN HYDROMETALLURGY:

PRAGMATISM AND SCIENCE

Gérard COTE and Alexandre CHAGNES

Ecole Nationale Supérieure de Chimie de Paris – ENSCP and Université Pierre et Marie Curie – Paris6 - Laboratoire d'Electrochimie et de Chimie Analytique -

UMR7575 CNRS-ENSCP-Paris6, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France

Solvent extraction is a separation technique well established in various

sectors of activity including hydrometallurgy, the nuclear industry, petrochemistry, the food and pharmaceutical industries, etc. In the past forty years heavy investments were made throughout the world to build large solvent extraction plants for producing high added value materials.

In hydrometallurgy, copper is the most illustrative example as Leaching-Solvent Extraction-Electrowinning (L-SX-EW) technology accounts for about 20% of the total world primary copper production. The separation of cobalt from nickel is another example for which solvent extraction has proven to be technically and commercially successful. The reprocessing of used nuclear fuels with the PUREX process is also a successful example where solvent extraction is a key technology. Currently, a large project is under development in New Caledonia for the recovery of nickel from laterites. Many other solvent extraction plants of medium or small size have been successfully developed throughout the world for the recovery of various valuable materials. The separation of individual rare earths, the recovery of gallium from the Bayer liquors, the recycling of platinum group metals, etc., are typical examples.

Though solvent extraction is often considered as a mature technique, many research teams work on its development worldwide and the literature on the subject is still abundant. In spite of this encouraging dynamism, the use of solvent extraction in hydrometallurgy encounters severe technical, economical and environmental constraints which make difficult the development of new extractants and new processes, beyond the laboratory scale. Furthermore, fundamental questions arise from recent advances in the speciation in the organic solvents, as for instance the problem of the modelling of equilibria in the presence of supramolecular organisations (reversed micelles, microemulsions, etc.). The present paper has four main objectives:

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- To give an overview of the extractants commercially available today. Indeed, over the last decade many changes occurred. Several suppliers have ceased to produce extractants, others companies amalgamated. Furthermore, the notion of reagent has shifted in some cases to the notion of service (the extractant is then sold with a process). “Who is who” today?

- To discuss the crucial problem of the ageing and the “deformulation” of the

extraction solvents with time, with the associated impact on the environment. In the literature, most authors report data obtained with fresh organic solutions and, when the sustainability of the systems is tested, which is very scarce, the most often only a few extraction – scrubbing – stripping cycles are performed. This question will be illustrated with various classical extractants.

- To exemplify the modern strategies to design entirely new extractants in

response to new challenges. The design of extractants for the separation of actinides(III) from lanthanide(III) in the reprocessing of used nuclear fuels will be treated in detail. Other examples will be presented.

- To point out the existence of supramolecular organisations in many “classical”

solvent extraction systems, with the induced macroscopic properties (3rd phases formation, catalysis, etc.), and to make a state-of-the art in the approaches for modelling the metal extraction equilibria in such systems.

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TRENDS IN SORBENTS FOR SOLID PHASE EXTRACTION

Rosa Maria MARCÉ, Núria FONTANALS, Francesc BORRULL

Department of Analytical Chemistry and Organic Chemistry

Universitat Rovira i Virgili Campus Sescelades, s/n

43007 Tarragona, Catalonia e-mail: rosamaria.marce@urv.cat

The determination of organic compounds in areas such as environmental, biological or food analyses, at low levels requires efficient sample preparation techniques prior chromatographic techniques, to preconcentrate and/or clean-up the sample.

Solid-phase extraction (SPE) has become one of the most important sample pre-treatment techniques. In SPE, the analytes to be extracted are portioned between the solid-phase and a liquid phase (samples matrix), and analytes must have greater affinity for the solid-phase than for the sample matrix. The choice of sorbent is therefore a key point in SPE to obtain selectivity and capacity. Numerous materials can be used as SPE sorbents. Thus, the research in SPE is mainly focused on the development of new sorbents to enhance the extraction of polar compounds and to obtain selective sorbents for specific applications [1,2]. Several examples of new synthesised materials that are either commercially available or “in-house” prepared and their application to SPE are described.

Classically, they are divided into silica-based, carbon-based and macroporous polymeric sorbents. Of these, polymeric sorbents are the most suitable because of their chemical stability and broad range of physico-chemical characteristics. The type of sorbent, its structure and its interactions with the solute are clearly related to the efficiency of the extraction process. Thus, when new materials are being developed, it is equally important to define both their chemical structure, which determines the type of interactions, and their morphology (i.e. specific surface area, porosity, particle size, etc.), which determines the mechanical properties and, eventually, the stability of the resin.

One of the general features of the macromolecular polymeric sorbents is its porous structure and high specific surface area, which is essential to increase the retention capability towards the compounds. These sorbents are known as highly crosslinked sorbents, which are macroporous styrene-divinylbenzene (St-DVB) polymers with specific surface area up to 800 m2 g-1. A step further are hypercrosslinked resins, which posse a significant content in microporous and

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therefore, display an extremely high specific surface area (up to 2000 m2 g-1) and hence excellent sorption properties. Some studies have shown that recoveries are best when hypercrosslinked sorbents are used and not sorbents with a lower crosslinking degree (and therefore with a lower specific surface area). For instance, the hypercrosslinked resin Hysphere-SH gave better recoveries than conventional macroporous resin PRLP-S in the on-line SPE of substituted phenols [3].

Other options to enhance the extraction of polar compounds are copolymers with a polar monomer and chemically modified polymers.

Commercial sorbents based on copolymers with a polar monomer include, for instance, OASIS HLB (from Waters), Abselut Nexus (from Varian) and efficient extraction of polar compounds have been obtained from these sorbents [4,5]. Examples of in-house sorbents are those of the Trockimzuck group [6], based on several polar monomers, and those of our group, using 4-vinylpyridine-divinylbenzene (4VP-DVB) [7], N-vinylimidazole-divinylbenzene [8] or hypercrosslinked resins which have different hydroxyl group contents [9] and good recoveries for polar compounds, such as phenol, were obtained in all cases, being the best one for the hypercrosslinked resin.

Chemically modifying existing polymers is another method for obtaining polar sorbents. This option has been adopted by either research groups to improve the available sorbents or manufacturers. In our research group a commercial St-DVB resin was modified with such moieties as o-carboxybenzoyl [10], 2-carboxy-3/4-nitrobenzoyl and 2,4-dicarboxybenzoyl [11]. When these resins were tested by on-line SPE, the recoveries were higher than their unmodified analogues. Examples of commercially available chemically modified resins are: Isolute ENV+ (modified with hydroxyl groups) from IST, Strata X (with vinylpyrrolidone) from Phenomenex or Speed-Advanta (with carboxyl moieties) from Applied Separations.

As regards to increase the selectivity, in the last few years molecularly imprinted polymers (MIPs) have been increasingly used as sorbents in solid-phase extraction [2]. MIPs are tailor-made materials which have specific cavities for a template molecule and they can be synthesised by several techniques. The simplest one is polymerisation in solution, which gives rise to a monolith which must be crushed before use. Other techniques are precipitation, which gives rise to spherical particles with the advantages that these have for applications such as chromatography, suspension, two-step swelling, emulsion core-shell, etc. [2]. At present there are already some commercial MIPs but most of the published results are obtained with “in house” prepared MIPs.

Molecularly imprinted solid-phase extraction (MISPE) has mainly been used in environmental [2,12,13] and biological samples [2,14]. Of the latter, biological fluids such as urine, serum or plasma have been the most frequently analysed samples, but relatively few studies focus on tissue samples. MISPE has been used in both on-line and off-line mode, coupled to liquid chromatography.

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In this lecture we also present an overview of the various MIP applications developed by our group. All MIPs have been synthesised by using polymerisation in solution and, when possible, MISPE has been on-line connected to liquid chromatography. The synthetic procedure and the different steps for solid-phase extraction are described and examples are given of the MIPs synthesised using as templates different environmental pollutants or drugs. For instance, naphthalenesulfonic acids can be extracted from 500 ml of sample without interference from other compounds in the sample, using an MIP synthesised with 1-naphthalenesulfonic acid as template [12]. Anti-inflammatory drugs such as ibuprofen, naproxen, diclofenac or fenoprofren can be also extracted from river and waste water samples by using ibuprofen as the template of the MIP, because of its crossreactivity [15].

As regards biological samples, urine and tissue samples have been analysed. It is interesting to use MIPs to analyse tissue samples because their matrix is complex. The use of an MIP for the enrofloxacin enables two fluoroquinolones to be selectively extracted from pig liver after a two-step SPE, using an OASIS cartridge and the MIP, at the levels required by the EU legislation [16], which states that the total sum of both fluoroquinolones should not exceed 200 µg kg-1.

In urine samples, the high selectivity of an MIP for ciprofloxacin, a fluoroquinolone used in human medicine, enables the chromatographic separation to be eliminated and the urine extract to be directly determined with mass spectrometry after a two-step SPE (using OASIS and the MIP), which involves a significant decrease in analysis time [17].

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29(2006)1230

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ION-COORDINATING POLYMER-SUPPORTED REAGENTS: SYNTHESES AND SELECTIVITIES

Spiro D. ALEXANDRATOS

Hunter College of the City University of New York, Department of Chemistry, 695

Park Avenue New York, NY 10021 USA

Polymer-supported reagents are comprised of ligands immobilized on to polymer supports. The polymers can have different physical forms and this presentation will focus on polymers as crosslinked beads. The beads are prepared, most commonly, from styrene, vinylbenzyl chloride, and glycidyl methacrylate via suspension polymerization. The crosslinking agent is, again most commonly, divinylbenzene or ethylene glycol dimethacrylate. The polymers are then functionalized with a wide array of ligands chosen on the basis of the final application. In this presentation, the focus will be on metal ion separations and the resulting polymers can be applied to environmental remediation, ion chromatography, sensor technology, hydrometallurgy, wastewater processing and nuclear fuel reprocessing. The applications require that the polymer-supported reagents display selective binding of targeted substrates with a rapid rate of complexation and high loading.

In three of many possible examples, it is known that imidazoles are selective for Cu(II), hydroxamic acids have a high affinity for Fe(III), and thiols bind Hg(II) and Ag(I).

In our latest work [1], the ionic affinity of a ligand is found to change when placed proximate to an auxiliary group that is capable of interacting

21

with the ligand. In the first set of experiments to be reported, phosphate is the ligand to which the metal ions bind and hydroxy groups are the auxiliary groups. The resins synthesized are phosphorylated glycerol, tris(hydroxymethyl)ethane, pentaerythritol, and pentaerythritol triethoxylate; phosphorylated glycol and a phosphonate resin are included as controls.

The metal ion affinities of Pb(II), Cd(II), Cu(II), Ni(II) and Zn(II) are determined from 10-4 N solutions in a background of 0.01 M nitric acid. Theeresults show thatthe two controls do not complex any of the metal ions from 0.01 M nitric acid. However, the phosphate affinity is significantly higher in the other polymers. For example, the percent Pb(II) complexed for the phosphorylated pentaerythritol, glycerol, pentaerythritoltriethoxylate, and tris(hydroxymethyl)ethane) is 96.1%, 89.9%, 90.7%, and 76.1%, respectively. The distribution coefficients for each of the five ions correlate linearly with their polarizability, as measured by the Misono softness parameter (0.400.30, 0.28, 0.25, and 0.24, for Pb, Cd, Cu, Ni, and Zn, respectively) [2]. The slope of the correlation, S, quantifies the selectivity of the polymer (the larger the value, the more selective the polymer). The selectivities for the pentaerythritol, glycerol, pentaerythritol triethoxylate, tris(hydroxymethyl)ethane, and glycol polymers are 3811, 1344, 1483, 474, and 21, respectively.

The correlation between the distribution coefficients and the softness parameter allows us to propose that the polarizability of the divalent ions is the dominant variable in determining the affinity and selectivity of a bifunctional coordinating polymer.

22

With the current set of polymers, the –OH groups activate the phosphoryl

oxygen by increasing its softness and the resulting differences in polarizability affect binding to the divalent ion. It is further proposed that the phosphoryl oxygen gains electron density and becomes more polarizable by hydrogen bonding from the -OH group to the phosphoryl oxygen which draws electron density from the phosphoryl oxygen and decreases back-donation of the pi-electrons into the phosphorus. There is significant evidence for such a mechanism, especially in studies with α-aminophosphonochloridates wherein hydrogen bonding between the N-H and P=O moieties makes the phosphorus more reactive toward nucleophiles because of being electron deficient through the hydrogen bonding interaction at the oxygen [3].

The studies have been extended to the synthesis of a coordinating polymer

with immobilized tris(hydroxymethyl)aminomethane which, after phosphorylation of the three -OH groups, shows the effect of -NH- as the auxiliary group [4].

The affinity with the divalent ions is most similar to that found with

tris(hydroxymethyl)ethane (with a selectivity of 229). The most significant

23

difference relative to the phosphorylated polyols is that the -NH- group results in a high affinity for trivalent ions and this may result from a stronger hydrogen bond interaction between the -NH- group and P=O ligand. (The strength of the hydrogen bond is determined through an analysis of the FTIR spectra.) Studies are continuing.

ACKNOWLEDGEMENT We gratefully acknowledge support from the US Department of Energy,

Office of Basic Energy Sciences, Separations and Analysis program. As indicated by the publications, Dr Xiaoping Zhu carried out the syntheses and characterization studies.

REFERENCES

1. S. D. Alexandratos, X. Zhu, Macromolecules, 38(2005)5981 2. M. Misono, Y. Ochiai, Saito, Y. Yoneda, J. Inorg. Nucl. Chem., 29(1967)2685 3. A. B. Smith III, L. Ducry, R. M. Corbett, R. Hirschmann, Org. Lett.,

2(2000)3887 4. S. D. Alexandratos, X. Zhu, Inorg. Chem., 2007, ASAP Article; DOI:

10.1021/ic061817h

24

SURFACE-TEMPLATED POLYMERS FOR REMOVAL OF FLUORIDE ION

Kazuya UEZUa , Hidenobu MIZUKIa, Hidetaka KAWAKITAb

a Graduate School of Environmental Engineering, The University of Kitakyushu

b Department of Chemistry and Applied Chemistry, Saga University

1. INTRODUCTION

Fluoride ion is extremely toxic to both animals and plants at high concentrations, and removal of fluoride ion from wastewater is an important subject for environmental conservation. The allowance level in the wastewater has been severe and was set to the fluoride concentration of 0.8 from 15 mg/L in Japan at 2001. In many countries, the level is set to a few mg/L [1,2].

Development of new adsorbent for selective separation of low-concentration fluoride ion from aqueous solutions, therefore, is of great significance. Recently it was reported that the adsorbent containing the Zr(IV)-phosphate complex captured fluoride ion selectively [3]. However, there are some problems including slow binding kinetics and low efficiency of the recognition sites of fluoride ion because the sites exist inside the polymer. Conventional adsorbent with macro pore (~102 nm diameter) also perform slowly because the access of the target molecules to the particle interior is limited by diffusion.

To realize the high-speed removal of fluoride ion, we prepared the polymer immobilized adsorption sites on the polymer surface with large-macropores (102~103 nm diameter) and meso pores (2~50 nm diameter) by surface template polymerization [4-6] and by using polystyrene as a porogen (Fig.1).

In this study, preparation conditions were determined so that the polymer captures the fluoride ion with the most speed, selectivity, and capacity. Furthermore, we evaluated the structure on the polymer surface. Also, we discussed the effect of adding polystyrene to polymer structure.

Fig.1. Surface templated polymer with large-macropores

25

2. EXPERIMENTAL

2.1 Materials In the present study, phosphoric acid oleyl ester (DOLPA), sorbitan

monooleate (Span80), divinylbenzene (DVB), polystyrene, and toluene were employed as the functional monomer, emulsion stabilizer, matrix-forming monomer, porogen, and diluent, respectively. NaF was used for the source of fluoride ion.

2.2 Preparation of surface templated polymer with large-macropores

Polystyrene was dissolved in toluene. DOLPA and Span80 were dissolved in a 45 mL of toluene-DVB solution. The mixture was sonicated for 15 min to give a water-in-oil (W/O) emulsion. After the addition of 2,2-azobis(2,4-dimethylvaleronitrile), emulsion polymerization was carried out at 60℃ for 3h under a flow of nitrogen. The polymer was washed with acetone to remove the polystyrene in the polymer.

2.3 Batch-mode adsorption of fluoride ion The equilibrium adsorption of fluoride ion by the surface templated polymers was

determined batchwise. To the polymers was added 10.0 mL of a 25 mg/L fluoride ion solution. The pH was adjusted to 3.0. The mixture was shaken in a thermostatted water bath at 30℃ for 24h. The amounts of fluoride ion adsorbed on the polymers were calculated from the decrease in the fluoride ion concentration measured by ion chromatography.

2.4 Measurement of the specific surface area, pore volume, and pore distribution

The porous morphology of each polymer was evaluated by N2 sorption porosimetry using a Micromeritics ASAP 2000 gas adsorption instrument, and the data were manipulated using the software supplied with the instrument.

The specific surface area and the pore distribution were analyzed by using the BET method and the BJH method respectively. Liquid extrusion porosimetry data were also acquired using a Micromeritics Autopore II 9220 and the dedicated software was used to generate appropriate porosity parameters.

3. RESULTS AND DISCUSSION

3.1 Polymer morphology Surface-templated polymers were prepared using 5 g/L and 10 g/L

polystyrene (PS) as a porogen in the preparation process, and designated as PS5 and PS10. Similarly, a reference polymer was prepared but without a polystyrene and is referred to as PS0. These polymers had large-macropores (Fig.2).

26

Fig.2. SEM image of (a) polymer surface (PS10), (b) cross section of polymer (PS10)

3.2 Adsorption capacity We evaluated the adsorption capacity for fluoride ion of PS0, PS5, and PS10

by batch-mode tests. The adsorption change with changing the PS concentration was shown in Fig.3. The amount of adsorption capacity for fluoride ion was increased with increasing PS concentration, ranging from 4 – 7 mg/g. The maximum capacity was 7 mg-F/g-polymer. Assuming that all Zr ions are fixed to the polymer, on a Zr ion were adsorbed around 2 fluoride ions. The adsorption capacity of these beads for fluoride ion has increased significantly compared with conventional surface templated polymers. The capacity is practical in industries. The recognition site of the fluoride ion was formed by phosphate acid of dioleyl phosphoric acid and zirconium.

Assuming a Langmuir adsorption isotherm, the selectivity for fluoride ion did not change by adding polystyrene.

Table 1 Porosity characteristics of each polymers

Fig.3. Adsorption isotherm of fluoride ion

(a) (b)

3 µm 300 µm

27

3.3 Porosity characteristics 3.3.1. Surface area and pore volume

The surface area data for all polymers calculated from the N2 sorption isotherms using BET treatment and from the liquid extrusion porosimetry data are shown in Table 1. In the case of the N2 sorption experiments the surface area was calculated from the adsorption branch of the isotherm. In comparing and contrasting these data sets, it is important to bear in mind that the N2 sorption experiment does not probe effectively pores about >200 nm while the liquid extrusion porosimetry experiment likewise may not account accurately for pores about <20 nm. N2 sorption data allow the BJH pore volume to be calculated, and liquid extrusion porosimetry allows a percent porosity to be deduced. It is important to appreciate that each of these experiments have their limitation, and each in effect provides a different measure of pore volume or porosity [7].

The specific surface area was constant at 35 – 40 m2/g irrespective of the PS concentration (Table 1). Threfore, the change of specific surface area is not a reason that adsorption capacity was increased. Also, the pore volume of PS10 has increased by 25% compared with PS0.

3.3.2 Pore size distribution

The pore size distribution was computed for each polymer using the BJH treatment of the N2 adsorption isotherm and from the liquid extrusion porosimetry assuming the pores to be cylindrical. Fig.4 indicates that PS0 has large-macropores (about 400 nm) and meso pore. In the specific area and the pore distribution, a big difference was not observed between PS0 and PS10 (Fig.5). Fig.4. Pore size distribution of PS0

28

Fig.5. Pore distribution of PS0 and PS10 (pore diameter 0 ~ 100)

4. CONCLUSION The surface templated polymers with large-macro-pore have been prepared

using by surface template polymerization with W/O/W emulsion. To control pore size in the polymer, polystyrene as a porogen was added before polymerization, and was removed after polymerization.

With the change of PS concentration, the adsorption capacity for fluoride ion was increased. By the effect of adding polystyrene, the pore volume has increased while maintaining the specific surface area.

We have been investigating the optimum condition of adding polystyrene or other porogen so that the surface-templated polymer has ideal large-macropores and meso pores for removal of fluoride ions.

REFERENCES

1. Y. Çengeloğlu et al., Sep.Purif. Technol., 28(2002)81 2. K. M. Popat et al., React. Polym., 23(1994)23 3. Mikami et al., Appl. Catal. B: Environm., 49(2004)173 4. K. Uezu et al., J. Chem. Eng. Jp., 32(1999)262 5. K. Uezu et al., Macromolecues, 30(1997)3888 6. K. Uezu et al., Anal. Sci., 20(2004)1593 7. S. Fiona et al, Macromolecues, 37(2004)7628

29

APPLICATIONS OF ION-EXCHANGE RESINS FOR ENVIRONMENTAL CLEAN-UP

Nalan KABAY

Ege University, Faculty of Engineering, Chemical Engineering Department 35100 Bornova, Izmir, Turkey

nalan.kabay@ege.edu.tr

The applications of ion exchange materials vary from water treatment to purification of antibiotics, vitamins and blood. This paper will address our research work on specific area of application, namely environmental clean-up. As society becomes ever more increasingly aware of environmental issues, pressures on governments to legislate for more stringent environmental controls, will demand that industries employ cleaner technologies. This paper will briefly explain our results obtained for the removal of boron from geothermal water and seawater by using ion exchange resins.

The World Health Organization and several European countries have adopted or recommended drinking water limits for boron of 0.3 mg/L although USA-EPA is considering adoption of 0.6 mg/L as the standard for drinking water. Boron is an essential plant nutrient, and some boron products are used to aid plant growth. Plants need small amounts of boron but high levels are toxic. The toxic action of boron in animals is not well-known. Effects of boric acid on human health and the environment depend on how much boric acid are present and the length and frequency of exposure. Effects also depend on the health of a person and/or certain environmental factors.

Among several methods of boron removal from aqueous solutions, the use of boron-selective ion exchange resins based on macroporous polystyrene matrices with N-methyl glucamine ligand seems to have still the highest importance for the elimination of boron. The presence of two vicinal hydroxylic groups allows boric acid and borates to form stable complex with the fixed group on the resin. Boron selective ion exchange resins (Diaion CRB 02 and Dowex XUS 43594.00) showed great performance for elimination of boron from geothermal waters containing high concentration of boron [1-4], seawater [5,6] and natural seawater RO permeate [7]. Recently, an advanced separation process for boron removal has been put forward by combining boron sorption on a fine powdered boron selective resin with a complex separation on microfiltration membranes. The so-called adsorption-membrane filtration (AMF) hybrid process integrates sorption efficiency with membrane separation of the selective resin in one step [5,6,8,9].

30

ACKNOWLEDGEMENT

The author would like to thank the Organizing Commitee of Ars Separatoria-2007 for the kind invitation to present this lecture and her co-workers cited in the various references for their efforts in making it all possible.

REFERENCES

1. M. Badruk, N. Kabay, M. Demircioglu, H. Mordogan, U. Ipekoglu, Sep. Sci. Technol., 34(1999)2553

2. M. Badruk, N. Kabay, H. Mordogan, U. Ipekoglu, Sep. Sci. Technol., 34(1999)2981

3. N. Kabay, I. Yilmaz, S. Yamac, M. Yüksel, U. Yüksel, N. Yildirim, O. Aydogdu, T. Iwanaga, K. Hirowatari, Desalination, 167(2004)427

4. N. Kabay, I. Yilmaz, S. Yamac, S. Samatya, M. Yüksel, Ü. Yüksel, M. Arda, M. Sağlam, T. Iwanaga, K. Hirowatari, React. Func. Polym., 60(2004)163

5. N. Kabay, M. Bryjak, S. Schlosser, M. Kitis, S. Avlonitis, Z. Matejka, I. Al-Mutaz, M. Yuksel, Desalination, (to be published)

6. M. Bryjak, J. Wolska, N. Kabay, Desalination, (to be published) 7. N. Kabay, S. Sarp, M. Kitis, H. Koseoğlu, O. Arar, M. Bryjak, R. Semiat, M.

Yuksel, Desalination, (to be published) 8. N. Kabay, I. Yilmaz M. Bryjak, M. Yüksel, Desalination, 198(2006)74 9. I. Yilmaz, N. Kabay, M. Yuksel, M. Bryjak, A. Koltuniewicz, Desalination,

198(2006)310

31

ORGANIC ION EXCHANGERS. SYNTHESES AND CHARACTERIZATION

Ecaterina Stela DRAGAN, Maria Valentina DINU, Ecaterina AVRAM “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41

A, 700487 Iasi, Romania; e.mail: sdragan@icmpp.ro

Organic ion exchangers in beads form are the most widely utilized materials in the purification, concentration and separation processes of inorganic and organic ions in many fields of science and industry [1-4]. Some original contributions in the preparation and characterization of porous organic ion exchangers will be briefly presented. The main types of synthetic ion exchangers were obtained by polymer-analogous reactions performed on porous styrene-divinylbenzene copolymers (S-DVB) [5,6] and porous acrylonitrile-DVB copolymers (AN-DVB) [7,8]. Porous S-DVB copolymers were used as substrate for the synthesis of weak and strong base anion exchangers by chloromethylation reaction followed by the reaction with secondary or tertiary amines. Different chloromethylation agents were employed. Weak base anion exchangers with tertiary or primary amine groups were prepared starting from AN-DVB copolymers by aminolyse-hydrolyse reaction with asymmetrical diamines or ethylenediamine (EDA), respectively. Strong base anion exchangers were obtained by quaternization reaction with alkyl halides of the tertiary amine groups. Chelating ion exchangers with iminodiacetic groups were prepared by the carboxymethylation reaction of the primary amine groups above mentioned. The starting porous copolymers were synthesized as beads with sizes in the range 90-200 µm and 0.315-1.0 mm by suspension polymerization technique in the presence of different porogens. The porous copolymers and the corresponding ion exchangers were characterized from the morphological point of view, following the functionalization-morphology correlations in different stages of the anion exchanger synthesis, and by their functional properties. The adsorption capacity for some transition metal ions was also examined.

REFERENCES

1. G. Alberti, M. Casciola, U. Constantino. Encyclopedia of Analytical Chemistry, Academic Press: London, 1995; Vol. 4, 2273

2. C. Luca, Encyclopedia of Separation Science, Academic Press: London, 2000, Vol. 4, 1617

3. A. W. Trochimczuk, Eur. Polym. J., 34(1998)1657 4. A. W. Trochimczuk, B. N. Kolarz, Eur. Polym. J., 36(2000)2359 5. S. Dragan, D. Csergö, I. Manolescu, A. Carpov, React. Polym., 5(1987)123 6. E. S. Dragan, E. Avram, D. Axente, C. Marcu, J. Polym. Sci.: Part A: Polym.

Chem., 42(2004)2451 8. S. Dragan, G. Grigoriu, Angew. Makromol. Chem., 200(1992)27 9. S. Dragan, M. Cristea, A. Airinei, Ig. Poinescu, C. Luca, J. Appl. Polym. Sci.,

55(1995)421

32

SEPARATION PROCESSES WITH MEMBRANE BASED HYBRID SYSTEMS

Andrzej KOŁTUNIEWICZ

Wrocław University of Technology, Faculty of Chemistry, Department of Chemical

Engineering, Norwida Street 4/6, 50-373 Wroclaw

Separation processes are used to transform a mixtures of substances into two or more compositionally-distinct products which are isolated in pure form when they are valuable products. Separation processes are also used for recovery, reuse or recycling some selected components e.g. water, solvents and chemical agents in variety of clean technologies. The increased world-wide competitiveness in production and also policy of sustainable development has attracted the industry attention onto the exploration of novel concepts required for improve current process designs. Membrane based hybrid processes have recently emerged as a category of most effective separation processes. The Webster's Dictionary [1] defines two main types of “hybrids,” i.e. “an offspring of two animals or plants of different races, breeds, varieties, species, or genera,” and more general which can be used in technology, i.e. “something that has two different types of components performing essentially the same function” [2]. Lipnitzki and Field [3] defined a hybrid process as a combination consisting of generally different, unit operations, which are interlinked and optimized to achieve a predefined task. They distinguished two different groups of hybrid processes, e.g.

1. Hybrid processes consisting of processes which are `essentially performing the same function'. In this case all processes in the package would be separation processes.

2. Hybrid processes which are an offspring of two different processes. In the case of membrane based hybrid processes this group includes the combination of membranes and a reactor. This definition includes different unit processes such as extractive

distillation [4] but excludes in-series-processes like a cascade of the same units like distillation columns or membrane units because the separation in principle could be achieved in one unit. Hybrid processes are more than just integrated processes. A true hybrid process take advantage from synergy of integration to solve technical and economic limitations that apply to at least one of the component unit operations and that could not be achieved either technically or economically alone'. Hybrid processes can be easily optimized because they have higher degrees of freedom, number of parameters and range of operation. Therefore integration of some conventional processes with membrane separation technologies permits the rationalization of direct and indirect energy consumption improving at the same time the product quality and the process capacity and selectivity. The strategy of introducing hybrid processes in the modern clean technologies is characterized by

33

advanced levels of automation capacity, modularity, and remote control. But it also includes upgrading and retrofitting of an existing process, thus reducing energy consumption and low costs, and could be regarded as one means of to form a both technically and economically viable technologies. According to above mentioned definitions, the membrane based hybrids can be divided onto the two main groups including membranes combined with other separation processes [5] and membranes combined with reactors. However, in practice there are four specific groups that could be distinguished among membrane separation hybrid systems, e.g. such as membranes combined with conventional unit processes [6], hybrid processes combining only different membrane separation processes [7], membrane contactors and membranes combined with some kind aggregation of separated substances.

Fig.1. Classification of membrane based hybrid processes Membranes with conventional unit processes

The first known membrane-based separation process was combination of pervaporation and distillation, being published for the dehydration of isopropanol+ ethanol mixtures by Binning and James [8] in 1958. It can overcome restrictions encountered using distillation alone, like the addition of a solvent which is removed in subsequent steps, pressure variations, and a high number of trays in the

Membrane contactors

MEMBRANE + REACTION

Membranes+ Absorption Distillation Extraction Flotation Centrifuges

Adsorption Ion exchange Biosorption Complexation Micelles Flocculation Precipitation Crystallization

Reactors Photoreactors Bioreactors Photo bioreactors Photo oxidation Biooxidation Denitrification

Membranes Aggregation

Membranes +

Unit Process

Membranes

Absorption Adsorption Distillation Extraction

PV RO ED NF UF MF LM

MEMBRANE + SEPARATION

MEMBRANE-BASED HYBRID SEPARATION PROCESSES

34

distillation columns. The PV process is integrated into the distillation process to reduce the number of trays by processing a side stream of the distillation column or to split the azeotropes before distillation but also as a polishing step of either the top or bottom product of the distillation column. Distillation/membrane hybrid processes have a potential for energy savings and, under some circumstances, are superior to the single separation processes, especially if high product purities are required. Design methodology for a membrane/distillation column hybrid process has been already evaluated [9-13].

Such systems are used for many applications such as: separation of methanol/MTBE/C, mixture [14], aroma concentrate [15] dewatering of solvents [16]. It was shown that pervaporation can easily be used to break the azeotrope of methanol and TAME [17]. Integrated distillation with vapor permeation is used for dehumidification of compressed air [18]. Distillation is also frequently coupled with RO in hybrid systems for water desalination, which has been shown to be technically and economically superior to nonintegrated MSF and RO systems [19] by improving the performance reducing water cost but also the cost of materials of construction, equipment, membranes, steam, energy, chemicals, etc. [20, 21]. A hybrid process that combines a vapor permeation process with absorption and stripping process was used for removal of volatile organic compounds (VOCs) from gas streams [22, 23], acetone recovery with hybrid comprising PV and absorption column [24], removal of VOCs from groundwater with PV and air stripping [25], removal of acid gases from natural gas [26]. There are also other hybrids of membranes with unit separation processes, such as systems combine ion-exchange membranes with solvent extraction processes [27]. Membrane-adsorption hybrid system may be also performed solely with adsorptive membranes [28]. Membrane adsorbers are a hybrid synthesis of these two technologies, aiming at combining the selectivity of chromatography resins with the high productivity associated with filtration membranes. Like perfusion beads, membrane adsorbers were developed as an alternative to conventional gel bead chromatography.

Membrane contactors form also the specific group of hybrids with high

level of integration between membranes and such separation processes as distillation, extraction and absorption or adsorption. In the membrane contactor these unit processes are performed directly in membrane module where the membrane plays a role of artificial interface between two fluids with mass transfer of separated component between them. This technique is performed by inserting a microporous membrane wall between the feed phase and a stripping phase. Referring to conventional unit separation processes performed in columns, many advantages of the membrane contactors can be pointed out. There are no loading, flooding or emulsification problems, except the pumping of the flowing phases, no stirring nor is mixing needed. One drawback occurs when using a membrane as it creates additional resistance that hinders diffusion from one phase to another, thus slowing down the separation. In most cases, the large surface area per volume

35

offered by hollow fiber modules overcomes this disadvantage. In most cases, the large surface area per volume offered by hollow fiber modules overcomes this disadvantage.

Membrane with aggregation process involves bonding of the separated

species firstly to some special bonding agent and then separating the aggregates from the stream by membrane separation processes. There are several ways of binding that are used in practice such as adsorption on pulverized adsorbent, biosorption on microorganisms or some biological materials, complexation [29], chelating [30], binding on polymers, coagulation, flocculation, precipitation, crystallization, micellar solubilization etc. Very promising way of the binding is using ion exchange resins, molecularly imprinted materials, functionalized polymers etc. It should be noted that several hybrid processes based on aggregation and other separation processes such as flotation [31-33]or centrifugation [34].

Membrane reactors and membrane bioreactors and photoreactors belong to

the recent achievements in process engineering. Separation of undesired components may be also carried out throughout their dematerialization by chemical conversion. Combining a membrane with a chemical reaction has been shown to offer advantages in a number of different instances [35], which can be performed in membrane module integrated with reactor or solely in membrane. The catalytic membrane enables an efficient three-phase contact between gaseous phase, liquid phase, and the active surface. The pore size of the catalytic layer can be adjusted in the mesoporous or macroporous range according to the needs of the reaction, with a narrow pore size distribution. Moreover, the membrane catalyst concept allows a tuning of the reaction rate by adjusting the pressure to suit variable operating situations, i.e., different feed concentration, flowrate, and so on[36, 37]. One of potentials application is the use of Pervaporation process to drive an equilibrated reaction. Reviews of the literature concerning membrane reactors reveal that a very large fraction of catalytic membrane reactor applications involves reversible reactions, which reach a thermodynamically limited conversion level in a conventional reactor [38-44]. By conducting, these reactions in a catalytic membrane wherein one product can selectively permeate through the membrane and out of the reaction zone, an overall conversion is attained which is much greater than that realized in the conventional reactor [45-56].

The utilization of bioreactors [57] with enzymes or whole cells immobilized is used in biotechnology and several research areas. The specially challenging task is the separation of xenobiotic from water and air environment when they are present even in much diluted form. The specific group comprise so called refractory chemicals which are very resistant for decomposition. New methods, such as photocatalytic reactions [58], allow in many cases a complete degradation of organic pollutants in very small and harmless species, without using chemicals, avoiding sludge production and its disposal. These processes are based on the electronic

36

excitation of a molecule or solid caused by light absorption (usually UV light) [59] that drastically alters its ability to lose or gain electrons and promote decomposition of pollutants to harmless by-products [60-63].

REFERENCES

1. P. B. Grove (Ed.), Webster's Third New International Dictionary of the English

Language, Merriam-Webster, Incorporated Springfield, MA, USA, 1993 2. N. H. Dickey (Ed.), Funk and Wagnalls New Encyclopedia, Funk & Wagnalls

Corporation, NY, USA, 1995 3. F. Lipnizki, R. W. Field, P.-K. Ten, J. Membr. Sci., 153(1999)183 4. A. Szanyi, P. Mizsey, Z. Fonyo, Chem. Eng. Process.,43(2004)327 5. X. Feng, C. Y. Pan, J. Ivory, D. Ghosh, Chem. Eng. Sci., Vol 53. No 9. DD 1689-

1698, 1998 6. J. K. Gienger, R. J. Ray, AIChE Symp. Ser. 84(261)(1988)168 7. R. Wodzki, G. Sionkowski, G. Pozniak, Sep. Sci. Technol., 34(1999)627 8. R. C. Binning, F. E. James, Pet. Renifer, 37(1958)214 9. W. Stephan, R. D. Noble, C. A. Koval, J .Membr. Sci., 99(1995)259 10. T. Pettersen, K. M. Lien, J. Membr. Sci., 99(1995)21 11. A. M. Eliceche, M. C. Daviou, P. M. Hoch, I. O. Uribe Computers Chem. Eng.,

26(2002)563 12. J. Bausa, W. Marquardt, AIChE Annual Meeting 1998, Miami, Florida,

November 16-21, 1998 13. T. Pettersen, K.M. Lien, J. Membr. Sci., 99(1995)21 14. Y. Lu, L. Zhang, H.-L. Chen, Z.-H. Qian, C.-J. Gao, Desalination, 149(2002)81 15. S. Alvarez et al., J. Food Eng., 46(2000)109 16. S. Sommer, B. Klinkhammer, T. Melin, Desalination, 149(2002)15 17. S. Marx, P. van der Gryp, H. Neomagus, R. Everson, K. Keizer, J. Membr. Sci.,

209(2002)353 18. Y. Wu, et al., J. Membr. Sci., 196(2002)179 19. E. El-Sayed, et al., Desalination, 128(2000)231 20. A. M. Helalet al., Desalination, 154(2003)43 21. E. El-Sayed et al. Desalination, 128(2000)231, E. Cardona et al., Desalination,

153(2002)167 22. T. K. Poddarl, K. K. Sirkar, J. Membr. Sci., 132(1997)229 23. D. Roizarda, V. Teplyakov, E. Favre, L. Fefilatiev, N. Lagunstsov, V.

Khotirnsky, Desalination, 162(2004)41 24. E. Marki, B. Lenti, Gy. Vatai, E. Bekassy-Molnar, Sep. Pur. Technol., 22-

23(2001)377 25. M. R. Shah, R. D. Noble, D. E. Clough, J. Membr. Sci., 241(2004)257 26. B. D. Bhide, A. Voskericyan, S. A. Stern, J. Membr. Sci., 140(1998)27 27. S. E. Kentish, G. W. Stevens, Innovations in separations technology for the

recycling and re-use of liquid waste streams 28. L. R. Castilho, F. B. Anspachl, W.-D. Deckwer, J. Membr. Sci., 207(2002)253

37

29. P Baticle, C. Kiefer, N. Lackhchaf, O. Leclerc, M. Persins, J. Sarrazin, Sep. Purif. Technol., 18(2000)195

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209(2002)519 35. Q. L. Liu, H. F. Chen, J. Membr. Sci., 196(2002)171 36. K. Daub, R. Dittmeyer, Proceedings of the 15th International Symposium on

Chem. React. Eng. (ISCRE 15), Newport Beach, CA, September 13–16, 1998 37. K. Daub, G. Emig, M.-J. Chollier, M. Callant, R. Dittmeyer, Chem. Eng. Sci.,

54(1999)1577 38. K. Mohan, R. Govind, AIChE J., 34(1988)1493 39. K. Mohan, R. Govind, AIChE J., 32(1986)2083 40. K. Mohan, R. Govind, Ind. Eng. Chem. Res., 27(1988)2064 41. N. Itoh, AIChE J., 33(1987)1576 42. Y. M. Sun, S. J. Khang, Ind. Eng. Chem. Res., 29(1990)232 43. Y. M. Sun, S. J. Khang, Ind. Eng. Chem. Res., 29(1990)232 44. S. Vemiya, N. Sato, H. Ando, E. Kikuchi, Ind. Eng. Chem. Res., 30(1991)585 45. I. K. Song, W. Y. Lee, Appl. Catal. A: Gen., 96(1993)53 46. H. Kita, K. Tanaka, K. Okamoto, M. Yamamoto, Chem. Lett., (1987)2053 47. M. O. David, Q. T. Nguyen, J. Neel, J. Membr. Sci., 73(1992)129 48. K. Okamoto, M. Yamamoto, Y. Otoshi, T. Semoto, J. Chem. Eng. Jpn.,

26(1993)475 49. H. Kita, S. Sasaki, K. Tanaka, K. I. Okamoto, M. Yamoto, Chem. Lett.,

(1988)2025 50. H. Kita, S. Sasaki, K. Tanaka, K. I. Okamoto, M. Yamoto, Chem. Lett.,

(1988)2025 51. X. Feng, R. Y. M. Huang, Chem. Eng. Sci., 51(1996)4673 52. L. Bagnell, K. Cavell, A. M. Hodges, A. W. H. Mau, A. J. Seen, J. Membr. Sci.,

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38

61. M. Schiavello (Ed.), Photoelectrochemistry, Photocatalysis and Photoreactors, Fundamentals and Developments, Reidel, Dordrecht, 1985

62. E. Pelizzetti, N. Serpone (Eds.), Photocatalysis. Fundamentals and Applications, Wiley, New York, 1989

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39

PLASMA MODIFIED POLYMER MEMBRANES

Marek BRYJAK

Faculty of Chemistry, Department of Polymer and Carbon Materials, Wroclaw University of Technology, 50-370 Wroclaw, Poland

So far, life on Earth has made use of three states of matter: solid, liquid and gas. The fourth state – plasma – has appeared to be phantasmagoria with rather magical than scientific connotation. Aurora and lightening can be found in poetic terminology even these phenomena are connected to plasma state, indeed. Cosmology tells us that with more than 99% domination of plasma in the Universe, plasma should be considered as the fundamental state of matter. The cosmic forms of plasma include the atmospheres and interiors of stars, the star wind, planets magnetosphere, the wasteland between stars and galaxies, some effects of quasars, supernovas and the compact spinning stars.

Plasma has been tamed by human beings in 19th century when William Crookes started his experiment with florescent tubes. In 1929, Irvin Langmuir, to describe the gas phenomenon in the glass tubes used the term plasma. Today, the annual turnover of plasma business is estimated to be around 250 billion USD. Plasma application encompasses a variety of disciplines ranging from plasma physics to some aspects of chemistry and/or material science. Its ‘interdisciplinary’ nature put onto agenda all plasma components including ionized gases that range from weakly ionized to highly ionized, from collisional to collisionless, and from cold to hot ones. Different types of plasmas are related to different applications and different natural phenomena. The diversity of what is included to "plasma science" makes the subject difficult to categorize. On the other side, wide diversity makes plasma easy to be used in many applications and technological developments. Below is a brief list of some of the technological applications of plasma. Surface processing (nano-machinery construction), volume processing (flue gas, liquid and solid waste treatment), displays (field emitter arrays, plasma displays), chemical synthesis (plasma spraying, diamond-like layer deposition), light sources, surface treatment (hardening, welding, cutting, drilling), medicine (sterilization), isotope separation, beam source, lasers, etc.

The market demand for new membrane materials is growing year by year. However, it is not expected that new polymer materials will be available in large extent soon. The global tendency is to keep annual plastic production at the level of 200 millions tons and to use only the commercialized plastic materials. Hence, to be up to that request, the typical materials should be subjected to change their properties. One of the useful methods to reach that goal is plasma modification. There are two additional issues of plasma modification to be noteworthy here. The technique meets most of ecological limits for clean technology and it is one of the

40

fastest methods. The modification lasts usually 1-2 minutes. For these reasons, it is one of the most commonly used ways for alteration of membrane properties and tailoring them to a particular request.

When plasma acts on a polymer membrane, two opposite processes can take place: ablation and deposition. The first one causes etching of polymer chains and loss of material while the second presents deposition of plasma polymer on the surface and a measurable increase in sample weight. Surface chemistry alteration appears in both presented processes. Having available such powerful tools as plasma devises are, almost each material scientist is able to prepare membranes with the requested properties. Moreover, to do that, the scientist needs usually to have on stock one typical porous membrane. For more details on a membrane modification protocol the reader is asked to look at our second contribution. In this paper some general findings are being described.

PLASMAS OF NON-POLYMERIZABLE SPECIES

Such pure gases as Ar, N2, O2, CO2 and NH3 as well as gas mixtures were

studied. In almost all cases, an increase in pore diameter and enlargement in pore size distribution showed the membrane ablation as the dominant process. However, in same cases deposition of freed fragments of etched polymer chain can interfere to the process. The observations were confirmed by evaluation of surface energy through the contact angle measurements. After improvement of surface hydropilicity within the first period of the process the hydrophobicity recovery was noted. After modification, the hydrophilic character of membrane diminished with time of storage. It was shown that surface chemistry can be determined by means of XPS spectroscopy but more valuable data on surface acid-base character can be detected by contact angle measurements with contact angle surface titration.

PLASMAS OF POLYMERIZABLE SPECIES

Such vapors as AllOH, AllNH2, ButNH2 and AAc were mixed with Ar and

used for membrane modification. In same cases, membrane ablation dominated but most frequently observed process was polymer deposition. Depending on the geometry of plasma chamber, concentration of polymerizable component as well as time of deposition and energy of plasma some different layers were prepared. The spectroscopic studies (XPS and ATR-FTIR) allow one to qualify and quantify surface functionalities. The obtained membranes served for several approaches: as the supports for enzymes immobilization, as multi-layer NF membranes with an extraordinary good effect to split multivalent and monovalent ions or as brush like membranes that behaved as smart elements (membrane valves).

41

The graph below summarizes our efforts on plasma modified membranes.

UF membrane with anti-

fouling activity

NF membrane

with acive layer

UF membrane for enzyme

immobilization

UF membrane

with requested

pore diameter

MD membrane

Teflon-like

type UF MEMBRANE

NF

membrane

With various

layers

PV membrane

Polymerized

various polymers

Brush like membrane

Smart membrane

42

FUNCTIONALISED MAGNETIC FLUIDS FOR SEPARATION AND TARGETED DELIVERY

Pawel PLUCINSKI

University of Bath, Department of Chemical Engineering, Claverton Down, Bath, UK

While describing our students’ the potential driving forces for separation during the first lecture on the “Separation Processes”, we mention the magnetic force as one of the possibilities. However, we will probable never mention it again in a series of lectures.

Colloidally dispersed magnetic nanoparticle (NP) suspensions (magnetic fluids) show considerable promise for a wide range of applications, including as sealants, damping agents, storage media, contrast agents in MRI, catalysts, drug delivery vehicles, and separation aids. In many cases, these colloidal suspensions, consist of magnetite (Fe3O4) or maghemite (Fe2O3) nanoparticles, typically ~10 nm in size, coated with surfactants, polymers or organometallic compounds both to stabilise the particles in suspension and to provide favourable surface properties that are tailored for specific applications of interest.

This contribution focuses mainly on the application of magnetic fluids as separation aids and drug delivery vehicles. Both kinds of magnetic composites (magnetite- and maghemite-based magnetic fluids), show superparamagnetic behaviour, i.e. they are attracted to a magnetic field, but retaining no residual magnetism after the field is removed. Such behaviour allows the application of the external magnetic field to achieve effective separation of NPs from the liquid phase (and their subsequent reuse) or for their targeted guidance inside of human tissue.

The separation of functionalised magnetic NPs in the magnetic field (permanent or electromagnetic) can be applied for the recovery of toxic metal ions from wastewater or blood, amino acids, and proteins from fermentation broth as well as cells from aqueous media and/or from the tissue. The pH-controlled chemisorption of these compounds (metal ions, amino acids, proteins, etc.) onto functional groups immobilised at the surface of NPs allows their subsequent stripping and reuse of NPs in the continuous separation processes. The immobilisation of catalytic functionality onto magnetic NPs facilitates the separation of quasi-homogeneous catalysts from the product stream.

The response of functionalised NPs to the applied external magnetic field can be also used for the targeted delivery of therapeutic drugs, genes and radionuclides in the biomedicine.

43

II. SHORT LECTURES

44

ANALYSIS OF LIQUID-LIQUID DISTRIBUTION CONSTANTS OF 8-HYDROXYQUINOLINE AND ITS DERIVATIVES

Waldemar ROBAK1, Wiesław APOSTOLUK2,*, Barbara WOŹNIAK 2

1The Tadeusz Kościuszko Land Forces Military Academy, Czajkowskiego 109, 51-150 Wrocław, Poland

2Hydrometallurgy Group, Division of Chemical Metallurgy, Wrocław University of Technology, WybrzeŜe Wyspiańskiego 27, 50-370 Wrocław, Poland

1. INTRODUCTION

8-hydroxyquinoline and its derivatives are known as chelating ligands forming stable complexes with a great number of metal ions. In chemical analysis and hydrometallurgical practise, 8-hydroxyquinolinols of different hydrophobicity are used as chelating extractants suitable for separation and preconcentration of several elements [1-12]. It should be noted that different 8-quinolinols and their complexes with Cu(II) are biologically active [13-19].

The distribution of 8-hydroxyquinoline, HQ, in organic solvent - water systems can be written as follows:

)()( oa HQHQ ⇔ with equilibrium constant a

oD HQ

HQK

][

][= , (1)

where indices a and o refer to the aqueous and organic phases, respectively.

The distribution ratio, D, is defined as the ratio of analytical concentrations of HQ is equal to the ratio of its analytical concentrations in both phases:

)(

)(

aHQ

oHQ

c

cD = (2)

In acidic solutions 8-hydroxyquinoline is protonated and its cationic form, H2Q

+, behaves as a weak diprotic acid:

,)()(2++ +⇔ aa HHQQH

a

aaa QH

HQHK

][

][][

21 +

+

= (3)

,)()()(−+ +⇔ aaa QHHQ

a

aaa HQ

QHK

][

][][2

−+

= (4)

Analytical concentration of HQ in the aqueous phase is equal to the sum of equilibrium concentrations of its neutral and ionic species:

45

)][

1][

(][][][][ 2

12)(

a

a

a

aaaaaaHQ H

K

K

HHQQHQQHc +

+−+ ++=++= , (5)

while the distribution of HQ is equal to

a

a

a

a

D

H

K

K

H

KD

][1

][ 2

1+

+

++= , (6)

Eq. (5) and (6) permit to evaluate the distribution ratio of 8-hydroxyquinoline and its derivatives within the whole range of pH of the aqueous phase. The diluents applied in metal extractions influence both the physical properties of the organic phase (e.g. density and viscosity) and the interfacial phenomena, as well as extraction equilibria and kinetics [1,6,20]. In the extraction systems involving 8-quinolinols, the non solvating and solvating diluents are frequently used [1,2,11,12,19,21,22]. The empirical model of solvent effects of Kamlet and Taft [23] has been applied for analysis of liquid – liquid distribution constants of 8-hydroxyquinoline and its 2-, 4- and 5-methyl derivatives in twenty organic solvent – water systems [24]. The present work deals with the following subjects: (i) hydrophobicity and lipophilicity of 8-quinololinols of different structure which are the factors governing their distribution in fixed organic solvent/water system; (ii) analysis of solvent and ionic strength effects on the distribution of 8-hydroxyquinolinols at 25° C; (iii) the effect of temperature on the distribution of different 8-quinolinols. The structures and names of considered 8-quinolinols and their distribution constants in organic solvent/water and/or organic solvent/aqueous solution systems [22,25-49] are collected in the files which could be available by request of editors and/or readers.

2. MODELS AND COMPUTING

The following multiparametric linear model has been used:

),,,,,,(log 22* IHLBHLBfK HD δβαπ= (7)

where KD stands for the distribution constants of all 8-quinolinols as solutes partitioned between the phases of an extraction system. Model (7) operates with the dimensionless parameters of dipolarity/polarizability (π* ), hydrogen bond donating (α) and accepting (β) abilities of solvents [50-53]. The cohesive energy density of solvents is expressed as a square of their Hildebrand solubility parameters, δH [54]. A hydrophile-lipophile balance, HLB, of a given 8-hydroxyquinolinol has been expressed in the McGowan scale [55].The ionic strength of the aqueous phase has been calculated according to the formula:

212

1zcI

ii∑= (8)

where ci and zi stand for the molar concentration and charge of i-th ion.

46

The effect of temperature upon the distribution constants of different 8-quinolinols has been expressed according to the following model:

),,,,,,)1(

,,,1

(log2*2

2/1

2/12

TTTTT

I

T

I

IT

I

T

HLB

T

HLB

TK H

D

δβαπφ+

= (9)

All calculations have been performed as previously [24,55-59] by means of multiple regression analysis. The assessment of statistical validity of derived correlations has been made applying the values of determination coefficient (R2), cross-validation coefficient (Q2), standard deviation (S.D.) and test function, F, of Fisher-Snedecor (F-statistics) calculated for N experimental point. The dissociation constants of all considered 8-quinolinols as well as their molar intrinsic volumes and HLB in McGowan scale are collected in Table 1.

Table 1. Characteristics of 8-hydroxyquinoline and its derivatives

Solute t, oC pKa2 pKa1 I Ref. Vx, cm3mol-1 HLB Go

HQ 20 4.67 9.77 0.2 8 110.30 6.28

25 4.85 9.95 0.1 6

25 4.99 9.81 0.01 10

2-M-Q 25 5.56 10.06 0.1 11 124.39 5.81

4-M-Q 20 5.23 10.28 0.2 8 124.39 5.81

5-M-Q 20 5.05 10.10 0.2 8 124.39 5.81

7-Dodecenyl-HQ 25 - 10.40 0.1 16 275.08 0.73

25 3.70 11.90 1.5 17

5,7-DM-HQ 25 4.45 12.10 0.1 15 138.48 5.33

5-OOM-HQ 25 4.32 9.99 0.1 18 242.98 3.31

2-M-5-MOM-HQ 25 5.28 9.77 0.1 19 158.44 6.16

2-M-5-EOM-HQ 25 5.21 9.77 0.1 11 172.53 5.69

2-M-5-BOM-HQ 25 5.20 9.96 0.1 11 200.71 4.74

2-M-5-HOM-HQ 25 5.07 9.97 0.1 11 228.89 3.79

2-M-5-OOM-HQ 25 5.16 9.88 0.1 11 257.07 2.84

5-Cl-HQ 25 3.84 9.29 0.01 10 122.54 5.87

5-NO2-HQ 25 2.69 6.31 0.01 10 127.72 5.70

25 2.64 6.38 0.01 20

25 2.60 6.42 0 20

5-Cl-7-I-HQ 25 2.70 7.90 0.1 21 148.37 5.00

5,7-DCl-HQ 25 2.90 7.40 0.1 21 134.78 5.46

2-M-5,7-DCl-HQ 25 3.73 7.97 0.1 24 148.87 4.98

25 3.74 8.02 0.1 24

25 3.62 8.12 0.1 24

5,7-DBr-HQ 25 2.60 7.30 0.1 21 145.30 5.10

25 3.30 7.20 3.0 23

5,7-DI-HQ 25 2.70 8.00 0.1 21 161.96 4.54

47

3. RESULTS AND DISCUSSION

3.1. Distribution of 8-quinolinols of different hydrophobicity in the given system

The effect of pH on the distribution ratio of three different 8-quinolinols in the systems with aliphatic hydrocarbons is presented in Fig. 1. As can be seen the decrease of distribution ratios of compared solutes observed at pH < 5 as well at pH > 9 is simply related to their increased solubility in acidic and alkaline solutions, respectively. At pH ranging from 5 to 9 the distribution ratio of each solute is near constant. In the whole range of pH of the aqueous phase, the values of distribution ratio depend on hydrophobicity of compared solutes and increase in the order: 8-hydroxyquinoline < 2-methyl-5-butyloxymethyl-8-hydroxyquinoline < 2-methyl-5-hexyloxymethyl-8-hydroxyquinoline. These results agree well with findings of Côté and Bauer [40].

-3

-2

-1

0

1

2

3

4

5

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

pH

log

D

2-M-5-HOM-HQ2-M-5-BOM-HQ8-HQ

Fig.1. The distribution ratio of different 8-quinolinols as a function of pH of the

aqueous phase

3.2. Distribution of 8-hydroxyquinoline and its derivatives in the extraction systems at 25 oC

The distribution constants of 8-hydroxyquinoline and its derivatives in different extraction systems at 25 oC have been found to fulfill the following correlation:

23*

22/1

2/1

2

10)46.014.4()19.000.1()22.004.2()13.091.1(

)061.0344.0()21.032.1(1

)41.047.4(

)013.0134.0()111.0321.0()28.093.4(log

H

D

III

I

HLBHLBK

δβαπ −⋅±−±−±+±+

±+±−+

±+

±−±+±=

48

R2 = 0.9296, Q2 = 0.9120 , S.D. = 0.20, F = 187.2, N = 128 (10)

3.3. Effect of temperature on distribution of 8-hydroxyquinoline and its derivatives in the extraction systems

Application of model (9) to the analysis the effect of temperature on distribution constants of 8-hydroxyquinoline and its derivatives in different systems results in the following equation:

,133.0142.17.518.2773.583.539

7.366.5668.165.697.595.312)

1(

1211194

72.384.378.329.772.840.1498log

2

*22/1

2/1

2

H

D

TTT

TI

TI

TI

I

T

HLBT

HLBTT

K

δβα

π

±−±−±+

±+±+±−+

±

+±−±+±=

R2 = 0.9915, Q2 = 0.9018, S.D. = 0.27, F = 1938, N = 158 (11)

The correlation (11) seems to be of excellent statistical quality, however, the squared cross-validation coefficient (Q2) is significantly lower than determination coeffient (R2). It means, that correlation (11) fairly well reproducing the the distribution constants of 8-hydroxyquinoline and its derivatives in different systems at 25 oC, should have the value of squared cross-validation coefficient similar to that in correlation (10). This conclusion is clear since the substitution of temperature 298 K in correlation (11) leads to the equation which is quite similar to correlation (10). Therefore, the moderate predictive power of correlation (11) indicates that it can be used for the rough estimation of unknown values of distribution constants of considered solutes in the particular system within the range of temperature from 20 to 50 oC. On the other hand, correlation (11) indicates that entalpy of distribution depends both on properties of solutes and diluents, respectively, as well as on the ionic strength of the aqueous phase. However, the available set of data is rather very limited and further improvement and/or verification of correlation (11) is practically impossible. As a result, the estimated values of enthalpy of distribution of 8-hydroxyquinoline and its derivatives should be treated with care. Hence, further studies of temperature effects on the distribution of considered solutes in the extraction systems are necessary to validated the importance of the derived correlations.

4. CONCLUSIONS

It has been demonstrated that the hydrophile-lipophile balance in the McGowan scale is a convenient descriptor of 8-hydroxyquinoline and its derivatives

49

distributed in the different extraction systems. For the first time, the distribution constants of 8-hydroxyquinoline and its derivatives have been also correlated with the ionic strength of the aqueous phase. The derived correlations prove that 8-hydroxyquinoline and its derivatives interact with diluents in the organic phase. First of all, they involve a positive contribution of dipolarity/dipolarizabity term of diluents which means that polar solvents promote the organic phase in the distribution of these solutes. On the other hand, however, the opposite contributions of hydrogen bond donation and hydrogen bond accepting abilities of diluents indicate that the nature and range of their specific interactions with 8-hydroxyquinoline and its derivatives in the organic phase is rather complicated. The correlation (11) describing the effect of temperature on the distribution of 8-hydroxyquinoline and its derivatives in considered extraction systems is of good statistical quality, however, its predictive power is rather moderate. As a result, correlation (11) can be used for the rough estimation of unknown values of distribution constants of 8-hydroxyquinoline and its derivatives in the particular system within the range of temperature from 20 to 50 oC. As it follows from correlation (11), the entalpy of distribution of 8-hydroxyquinoline and its derivatives depends both on properties of solutes and diluents, respectively, as well as on the ionic strength of the aqueous phase. However, the estimated values of enthalpy of distribution of different 8-hydroxyquinolinols should be treated cautionusly.

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51

45. Y. I. Korenman, Distribution Coefficients of Organic Compunds, Voronezh University, Voronezh, 1992 (in Russian)

46. D. A. Kniazev, Zh. Anal. Khim., 19(1964)273 47. A. Izquierdo, R. Compano, Microchim. Acta, (1983)371 48. J. G. Mason, I. Lipschitz, Talanta, 18(1971)1111 49. H. Hellwege, G. K. Schweitzer, Anal. Chim. Acta, 28(1963)236 50. Y. Marcus, Chem. Soc. Rev., 22(1993)409 51. Y. Marcus, Solvent Extr. Ion Exch., 10(1992)527 52. Y. Marcus, J. Phys. Chem., 95(1991)8886 53. Y. Marcus, J. Chem. Soc. Perkin Trans., (1994)1751 54. A. F. M. Barton, Handbook of Solubility Parameters and Other Cohesion

Parameters, CRC Press, Boca Raton, FL, 1983 55. W. Apostoluk, J. Szymanowski, Anal. Chim. Acta, 374(1998)137 56. W. Apostoluk, J. Szymanowski, Colloids Surf. A Physicochem. Eng. Aspects,

135(1998)227 57. W. Apostoluk, B. Gajda, J. Szymanowski, M. Mazurkiewicz, Anal. Chim. Acta,

405(2000) 321 58. W. Apostoluk, W. Robak, Anal. Chim. Acta, 548(2005)116 59. W. Robak, W. Apostoluk, P. Maciejewski, Anal. Chim. Acta, 569(2006)119

52

PHOSPHONIUM IONIC LIQUID AS AN EXTRACTANT OF ZINC F ROM HYDROCHLORIC ACID SOLUTIONS

Barbara MARSZAŁKOWSKA, Magdalena REGEL-ROSOCKA, Maciej

WIŚNIEWSKI

Institute of Chemical Technology and Engineering, Poznan University of Technology, Poznan, Poland

INTRODUCTION

Non-flammability, high thermal stability and non-volatility of ionic liquids

(Ils) account for their application in many fields, e.g., as solvents and catalysts for organic reactions, electrolytes in chemical sources of energy, plasticizers, bactericides, fungicides or antistatic agents [1-3]. Profound studies on the application of imidazolium ILs as solvents in separation processes have been carried out for eight years. No reports concerning phosphonium ionic liquids in extraction systems have been available to-date. However, they were considered to be prospective for separation of substances [4]. Looking for new, more efficient solvents, we have examined phosphonium ionic liquid as an extractant for the removal of zinc(II) from chloride media.

The aim of the work is to examine zinc extraction equilibria with Cyphos®IL101 in the presence of various electrolytes and in changing HCl concentration.

EXPERIMENTAL

The removal of zinc(II) is a very important issue in the case of spent pickling

solutions from hot-dip galvanizing plants. Several extractants (basic, acidic and neutral) were proposed for zinc(II) extraction from hydrochloric acid solutions in our previous works [5,6]. Tributyl phosphate (TBP) was chosen as the most effective one for zinc(II) extraction and stripping from the loaded organic phase. However, the main drawback of TBP is the transfer of high amounts of water to the organic phase that, in consequence, causes hydrolysis of TBP [7]. Moreover, only a concentrated reagent shows high extraction efficiency.

A phosphonium ionic liquid (Cyphos®IL101) supplied by Cytec Industry Inc. was dissolved in toluene (0.8 M) and used as an extractant. Toluene was applied to overcome some drawbacks caused by the high viscosity of ILs. The structure of the applied IL is presented in Fig.1. The composition of model aqueous solutions was as follows: 5 g/dm3 (0.077 M) Zn (II), 1.8% (0,58 M) HCl, 5 M Cl- (adjusted with NaCl).

53

P+C6H13

C6H13C6H13

C14H29

Cl-

Fig.1. A structure of Cyphos®IL 101 (trihexyltetradecylphosphonium chloride).

Moreover, preliminary kinetic studies in Lewis cell [8] were carried out.

Extraction process was carried on during six hours. Samples received from the organic phase were stripped with 2-folded excess of ammonia buffer (pH = 10) during 30 minutes. Next the aqueous phase was analysed.

RESULTS

The equilibrium results of zinc(II) extraction from the aqueous phase containing 5 g/dm3 Zn(II) indicate that Cyphos®IL 101 is a very effective extractant. An influence of various electrolytes (NaCl, NaBr, NaI, KCl, KBr, KI, Na2SO4, NaNO3), added in such quantities to obtain ionic strength I = 5, on Zn(II) extraction is studied and no dramatic effect is noticed, as it is shown in Fig.2.

The extraction isotherms of Zn(II) are presented in Fig.3. The presence of HCl slightly enhances metal transfer to the organic phase, that can be loaded with Zn(II) up to 40 g/dm3.

Na2SO4 NaBr NaI NaCl KBr KCl NaNO3 KI0

10

20

30

40

50

60

70

80

90

100

110

EZ

n(II), %

Fig.2. An influence of electrolyte presence on Zn(II) extraction with 0.8 M Cyphos®IL 101 (feed: 5 g/dm3 Zn(II), I = 5, without HCl).

54

0 10 20 30 40 500

10

20

30

40

1.8% HCl without HCl

Zn*

o, g

/dm

3

Zn*w, g/dm3

Fig.3. Extraction isotherms of Zn(II) extraction with 0.8 M Cyphos®IL 101 from feed containing 1.8% HCl (�) and without HCl (�).

Cyphos®IL 101 is very effective in equilibrium extraction, therefore we have decided to examine kinetics of zinc(II) extraction in Lewis cell. The preliminary results of percentage extraction are presented in Fig.4. As the results presented below are one of the first, they need to be repeated and statistically described. However, the results indicate that percentage extraction of Zn(II) increase in time and reaches plateau after 4 hours.

The studies were carried out for two stirring velocities 90 and 120 rpm. Extraction with 0.08 M Cyphos®IL 101 permitts to extract up to 40% of zinc(II) from the aqueous feed containing 1.8% HCl and 5 M Cl-. It seems that stirring velocity in the studied range does not affect zinc(II) transfer. As it has been described in our previous paper [9], zinc(II) can be extracted with Cyphos®IL 101 according to anion exchange mechanism, where two chloride ions from IL are exchanged into a negatively charged zinc tetrachlorocomplex.

)(2423)(3)(

2)(4 ]][)'[(]]['[22 ooww ZnClPRRClPRRHZnCl −+−++− ⇔++

−+ ++ )()( 22 ww ClH 1)

As it results from eq. 1, to extract Zn(II) completely molar ratio IL:Zn(II) should be equal to 2. Thus, the maximal extraction of Zn(II) under the studied conditions can amount 50% (IL:Zn(II) = 1).

55

0 50 100 150 200 250 300 350 400

0

10

20

30

40

50

EZ

n(II), %

Time, min

90 rpm 120 rpm

Fig.4. Zinc(II) extraction in Lewis cell for two stirring velocities 90 (�) and 120 (�) rpm with 0.08 M Cyphos®IL 101 (feed: 5 g/dm3 Zn(II), 1.8% HCl, 5 M Cl-).

CONCLUSIONS Cyphos®IL 101 seems to be a prospective reagent for zinc(II) extraction

from chloride media both without HCl and with HCl. More studies on kinetics of zinc(II) extraction must be done to better describe the process.

ACKNOWLEDGEMENT

The work was supported by the 32-139/2007 DS grant.

REFERENCES

1. K. R. Seddon, A. Stark and M. J. Torres, Pure Appl. Chem., 72(2000)2275 2. C. J. Adams, in: Ionic Liquids. Industrial Applications for Green Chemistry, ed.

R. D. Rogers and K. R. Seddon, Chapter 2, American Chemical Society, Washington, DC, ACS Symp., 818(2002)13

3. A. Cieniecka-Roslonkiewicz, J. Pernak, J. Kubis-Feder, A. Ramani, A. J. Robertson and K. R. Seddon, Green Chem., 7(2005)855

5. C. J. Bradaric, A. Downard, C. Kennedy, A.J. Robertson and Y. Zhou, Green Chem., 5(2003)143

6. M. Regel-Rosocka and J. Szymanowski, Solvent Extr. Ion Exch., 23(2005) 411 7. R. Cierpiszewski, I. Miesiąc, M. Regel-Rosocka, A. M. Sastre and J.

Szymanowski, Ind. Chem. Eng. Res., 41(2002)598 8. A. S. Kertes and M. Halpern, J. Inorg. Nucl. Chem., 20(1961)117 9. J. Niemczewska, R. Cierpiszewski, J. Szymanowski, Desalination, 162(2004)169 10. M. Regel-Rosocka, K. Cieszyńska, M. Wiśniewski, Przem. Chem., 85(2006)651

56

THE EFFECT OF β-CD DERIVATIVES STRUCTURE ON THE REMOVAL OF COPPER(II) IN ION FLOTATION PROCESS

Wanda ŚLIWA , Cezary A. KOZŁOWSKI*, Tomasz GIREK*, Władysław

WALKOWIAK**

* Institute of Chemistry and Environment Protection, Jan Długosz University of Częstochowa, Armii Krajowej 13, 42-201 Częstochowa, Poland;

fax: +48 34 3665322; e-mail: c.kozlowski@ajd.czest.pl **Chemical Metallurgy Division, Faculty of Chemistry, Wrocław University of

Technology, WybrzeŜe Wyspiańskiego 27, 50-370 Wrocław, Poland

Cyclodextrins (CDs) are cyclic oligomers composed of six, seven or eight anhydrous glucopyranosyl units (AGU) (known as α-, β-, γ-CDs, respectively) linked together by α-1,4-bonds. In the CD molecule, all secondary hydroxyl groups at C2 and C3 positions of the AGU protruded from the wide opening of the trunk shape of CD, whereas the primary hydroxyl groups at C6 are exposed from the opposite side [1]. It is widely acknowledged that CD can form complexes with a variety of organic and inorganic substances in its hydrophobic cavity [2-4]. Because of this unique property, CDs are applied in food, pharmaceutical and cosmetic industries.

In the work the β-CD derivatives for complexing metal ions in ion flotation process have been obtained. The substitution of functional groups, e.g. iodide, amino, and azide in the place of hydroxyl groups on primary carbon atoms has activated binding properties towards d-electron metal ions, such as Cu(II).

Structures of β-CD derivatives

Results of copper(II) flotation obtained with the use of nonylphenol

polyoxyethyl glycol ether as an non-anionic surfactant and β-CD derivatives as

X = I,

X = NH2

X = N3

1

2

3 O

OHHO

X

O

O

OH

HOX

O

OOH

OH

X

O

O

OH

OH

X

OO

OH

OH

X

O

OOH

OHX

O

O

OH

HO

X

O

57

complexation collector agent, show that the removal of Cu2+ decreases in the following order of CDs: 3 > 2 > 1. For derivative 3 with pH increase the copper(II) removal increase. The highest flotation removal, i.e. 90%, was found for β-CD derivatives 3 at pH of aqueous phase equal to1.0.

ACKNOWLEDGMENT

Financial support of this work was provided by Polish Science Foundation (Grant no. 4 T09C03032).

REFERENCES

1. S. F. Lincoln, Coord. Chem. Rev., 166(1997)255 2. W. Śliwa, T. Girek, Heterocycles, 60(2003)2147 3. T. Girek, C. A. Kozłowski, J. J. Kozioł, W. Walkowiak, I. Korus, Carbohydr.

Polym., 59(2005)211 4. C. A. Kozłowski, T. Girek, W. Walkowiak, J. Kozłowska, J. Inclusion

Phenomena and Macrocyclic Chem., 55(2006)71

58

KINETIC ASPECTS OF THE DEGRADATION OF SOLVENTS IN HYDROMETALLURGICAL LIQUID-LIQUID PROCESSES

Alexandre CHAGNES1, Gérard COTE1, Bruno COURTAUD2, Jacques THIRY2

1 Ecole Nationale Supérieure de Chimie de Paris - ENSCP Université Pierre et Marie Curie – Paris6 - Laboratoire d'Electrochimie et de Chimie Analytique - UMR7575 CNRS-ENSCP-Paris6 ENSCP, 11 Rue Pierre et Marie

Curie, 75231 Paris Cedex 05, France. 2 ArevaNC – Service d’Etudes de Procédés et d’Analyses

(SEPA), B.P. N°71 – 87250 Bessines sur Gartempe (France).

Liquid-liquid extraction is a well established technique for the production of both base and strategic metals throughout the world. A basic rule in hydrometallurgy is that the exploited processes should be sustainable, which requires in particular that the solvents of extraction used are resistant against degradation. In the recent past, a great effort of research and development has been made to design and syntheses highly selective molecules for specific applications, but the result was often disappointing as these new molecules were fragile. The case of the bis-triazynyl-pyridines (BTP) is a typical example, as these molecules developed for the separation of actinides(III) and lanthanides(III) in the reprocessing of used nuclear fuels are not resistant enough against degradation under chemical and radiological stresses.

The losses of the solvents in the hydrometallurgical applications of liquid-liquid extraction are a general concern. The losses occur according to various processes. The solubility in aqueous solutions is often a relatively important cause of losses associated with environmental problems. The question is rather documented in the literature. For instance, extractants such as Kelex 100, DEHPA, TBP exhibits aqueous solubilities at 25°C up to 0.06 g/L in 1 mol/L sulphuric acid, 75 ppm in ammonium carbonate solution and 0.4 g/L in water. Another source of losses is the ageing the solvents of extraction under chemical, thermal and radiological, if any, stresses. This question is much less documented in the literature. However, it is known that the dialkylphosphoromonothioic and dialkylphosphorodithioic acids hydrolyse, especially in acid media. Cyanex 301 and Cyanex 302 belonging to the family of the dialkylphosphinomonothioic and dialkylphosphinodithioic acids, respectively, degradate. Cyanex 301 degradates more rapidly than Cyanex 302, but the fomer can be regenerated whereas the second cannot.

In the exploited processes, a compromise has generally been found between the extractive properties of the solvents of extraction and their ageing. However, for

59

various reasons, this compromise might be altered. In particular, the composition of ores to be treated may change and this may induce a modification of the stresses undergone by the solvents of extraction. To exemplify this situation, the case of the presence of impurities such vanadium and molybdenum in the leaching solutions of uranium ores is considered. Presently, uranium ores are leached in sulphuric acid media and uranium(VI) is extracted by protonated amines according to an anion exchange mechanism. In certain ores, impurities such as vanadium and chromium are present and follow uranium during the leaching operations. As these two metals are known for their catalytic behaviours, their role in the ageing the solvents of extraction should be considered very cautiously.

The present paper is focused on the role of vanadium at the oxidation state +5. First, a brief overview of the oxidant power of vanadium (+V) toward organic compounds is presented. Then, the kinetic aspect of the degradation of the extraction solvent typically containing n-dodecane, as a diluent, tridecanol as a phase modifier and Alamine 336, as the extractant, is investigated and the results are interpreted by using the Michaelis-Menten mechanism. Futhermore, the degradation products have been identified and a model of the degradation mechanisms is discussed.

60

DEPENDENCE OF CHROMIUM(III) EXTRACTION FROM ALKALIN E SOLUTIONS ON TEMPERATURE

Barbara WIONCZYK

Institute of Leather Industry, Zgierska 73, 91-462 Łódź, Poland

e-mail: wionczyk@mazurek.man.lodz.pl

INTRODUCTION In the previous studies [1,2,3] on extraction of chromium, it was proved that chromium(III) is effectively extracted with trioctylmethylammonium chloride (Aliquat 336) from alkaline aqueous solutions as tetrahydroxochromate(III) anions. As the initial concentration of chromium(III) in the aqueous phase is lower than the initial concentration of extractant and concentration of Aliquat 336 in the organic phase does not exceed 0.05 M, the equilibrium of extraction of Cr(III) from alkaline media can be described as follows [3]: )(444)(4 )()(

)()( ao ClOHNCrROHCrNClRoa

−− +=+ It has been found that experimental values of conditional extraction

constants of chromium(III) (Kex) determined at 25ºC strongly depended on the ionic strength (I) of the aqueous phase in accordance with the following dependence [3]:

where: R2, S.D., F, and N stand for determination coefficient, standard deviation, Fisher-Snedecor test function, and number of experimental points, respectively.

In this work, I analyse the effect of temperature on equilibria of extraction of chromium(III) with Aliquat 336 from alkaline aqueous solutions.

EXPERIMENTAL

In all experiments, the initial concentrations of chromium(III) in the aqueous phases were kept within the range 0.003 – 0.024 M and were always lower than the initial concentration of Aliquat 336 varying from 0.02 to 0.05 M. The organic phases, solutions of Aliquat 336 in n-heptane, were modified with 1% (v/v) 1-decanol. The initial aqueous phases of chromium(III) were prepared from reagent

31.=N 1219;=F 0.10;=S.D. ;9878.0

;)65.086.1(1

)68.104.10()38.009.6(log

2 =

±−+

±−±=

R

II

IKex

(1)

(2)

61

grade KCr(SO4)2⋅12H2O, NaOH, and distilled water. Their ionic strength ranged from 0.1 to 0.8 M. Experiments were carried out at constant phase volume ratio of Vo/Va = 1:1 and in constant time (3 h) while temperature varied from 0 to 50ºC (273 – 323 K).

RESULTS AND DISCUSSION

Experimental values of extraction constants of chromium(III) (Kex) were correlated with the reciprocal of absolute temperature (T) and the ionic strength (I) of the aqueous phase. The calculations have been performed according to the following model:

log Kex = f(1/T, φ(I))

where: ℃(I) stands for the linear combination of terms involving ionic strength of the aqueous phase. The following correlation was found:

The fitting of experimental values of extraction constants of Cr(III) (Kex, observed) to these predicted from correlation (4) is presented in Fig.1.

Fig.1. The fitting of the experimental extraction constants of Cr(III) to those

calculated from dependence (4)

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

logK exCr(III), predicted

logK

exCr(III), o

bser

ved

159.N 1984;F 0.15;S.D. ;9741.0R

; I)30.033.1(I1

I)02.162.11(

T

6.840.3887)38.044.19(Klog

2

ex

====

±−+

±−±−±=

(3)

(4)

62

The very good statistical quality of correlation (4) allows for its use to determine the enthalpy change (∆Hex) of extraction of chromium(III) with Aliquat 336 from alkaline solutions. The value of enthalpy change calculated from Eq. (4) is positive and equal to 74.42±1.62 kJ/mol, which indicates that extraction of chromium(III) with Aliquat 336 described by Eq. (1) is endoergic. Therefore, it should be expected that this process is entropy driven. Indeed, the values of entropy change (∆Sex) in the studied extraction system, calculated from Eq. (5)

are always positive and varying from 242.0 to 313.7 J/(mol·K). Entropy change depends only on ionic strength of the aqueous phase and decreases with the increase of ionic strength according to the following correlation:

Good accordance of the values of ∆Sex determined from experimental data (Eq. 5) and these calculated from dependence (6) is illustrated in Fig.2. Fig.2. The fitting of entropy change calculated from Eq. (5) (∆Sex, observed) to those

predicted from correlation (6).

240

250

260

270

280

290

300

310

320

240 250 260 270 280 290 300 310 320

∆∆∆∆Spredicted , [J/(mol.K)]

∆∆ ∆∆S

obse

rved

, [J/

(mol

.K)]

159.N 2097;F K);J/(mol 2.87S.D. ;9637.0R

; I)0.30.14(I1

I)2.100.265()4.37.380(S

2

2ex

==⋅==

±−+

±−±=∆

,lnT

HKRS ex

exex

∆+=∆ (5)

(6)

63

The high and positive values of entropy change indicate that in Eq. (7) the negative term T∆Sex should prevail over value of ∆Hex giving negative values of free energy (∆Gex) in the studied extraction process.

.STHG exexex ∆−∆=∆

However, at suitably high ionic strength of aqueous phases and at lower temperatures, values of ∆Gex are positive, which means, that equilibrium of extraction of chromium(III) shifts to the left side of Eq. (1). The mean values of the ionic strength and entropy change as well as temperature at which ∆Gex is positive are presented in Table 1. Table 1. Values of free energy (∆Gex) of extraction of chromium(III) with Aliquat

336 from alkaline solutions. (Negative values of ∆Gex are indicated by “~“)

∆∆∆∆Gex, [J/mol] I

mol/dm3

∆∆∆∆Sex

J/(mol⋅K) 273

K

278

K

283

K

288

K

293

K

298

K

303

K

308

K

313

K

318

K

32

3

K

0.82 245 5972 4806 4729 3144 2885 1732 1089

0.72 252 4794 3531 2978 2413 1023

0.61 259 2963 1716 932 93

0,57 262 2002 411

0.54 264 1822 354

0.52 266 1389 1348

0.51 266 1807 1046

0.50 267 1596 871

0.41 275 388

0.32 284

0.22 296

0.12 314

CONCLUSIONS

Analysis of the effect of temperature on extraction of chromium(III) with Aliquat 336 from alkaline solutions allows for estimation of thermodynamic functions involved. The positive value of ∆Hex indicates the endoergic character of extraction described by Eq. (1) under studied conditions. At lower ionic strength of the aqueous phase, the high and positive values of entropy change indicate that the negative term T∆Sex prevails over positive ∆Hex, which means, that extraction of chromium(III) with Aliquat 336 is an entropy driven process. An increase of ionic strength over 0.6 M leads to positive values of ∆Gex and shifts the equilibrium of

(7)

64

extraction process towards formation of substrates. This negative effect of the ionic strength can be compensated in part for elevation of extraction temperature.

ACKNOWLEDGEMENTS

The work has been sponsored in part within the grant No. T09B04526 of the Ministry of Scientific Research and Information Technology (Poland). Professor Wiesław Apostoluk and Professor Witold A. Charewicz are gratefully acknowledged for fruitful discussion on the work.

REFERENCES

1. B. Wionczyk, W. Apostoluk, Hydrometallurgy ,72(2004)185 2. B. Wionczyk, W. Apostoluk, Hydrometallurgy, 72(2004)195 3. B. Wionczyk, W. Apostoluk, Hydrometallurgy, 78(2005)116

65

CROSSLINKED IMIDAZOLIUM TYPE IONIC LIQUIDS AND THE IR EXTRACTIVE PROPERTIES

Andrzej W. TROCHIMCZUK

Faculty of Chemistry, Wroclaw University of Technology Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland

The efficient removal of organic substances from complex aqueous

solutions is a very important process both from the environmental and the analytical point of view. Usually applied for this purpose is sorption, mostly on activated carbon and on polymeric sorbents. It is used for the decontamination, recovery of compounds and in preconcentration of compounds before their chromatographic analyses.

In order to maximize the uptake of organic substances from liquid phase new types of sorbents have been developed over last few decades. One groups of sorbents consists of polar, porous polymers such as crosslinked acrylonitrile [1,2], methacrylate copolymers [3] and various copolymers crosslinked with ethylene glycol dimethacrylates, tetramethylolpropane tetraactylate and trimethylolpropane trimethacrylates and triacrylates [4]. Such sorbents display better uptake of polar sorbates compared to the performance of traditional, non-specific sorbents based on the styrene-divinylbenzene copolymers.

In this work we would like to present some results of research on solid polymeric extractants, in which polarity of the extractant is obtain not by the introduction of the functional group, which has a free electron pair, like it was in the case of polar sorbents listed above, but is arising from the presence of cations and anions known from the chemistry of ionic liquids: imidazolium and (trifluoromethylsulfonate, trifluoroacetate, tetrafluoroborate). Such materials are obtained by microwave asssisted modification of lightly crosslinked vinylbenzyl chloride-divinylbenzene copolymers with methyl substituted imidazole and by subsequent ion-exchange of suitable anions.

The basic observation of the hydrophobicity/hydrophilicity balance of the obtained materials is illustrated in Fig.1, where it can be seen that, depending on the type of anion, water uptake changes enormously. The lowest water uptake is seen for resins in which the anion is shielding charge center. In such case the material is still consisting of ions yet is excluding water from the resin phase.

66

ionic form of the resin0 1 2 3 4 5 6

wat

er r

egai

n, g

of w

ater

/ g o

f res

in

0

2

4

6

8

BF4- CF3SO3

-

PF6-

CF3COO-

OH-

Fig.1. Water content of N-methylimidazol resin in various ionic forms.

As a quite hydrophobic and polar phase these resins should display some sorptive properties towards organic compounds. The sorptive properties have been tested using derivatives of phenol and aniline. The examples of sorption isotherms are seen in Figs.2-4.

2,6-dimethylphenol equilibrium concentration, mmol/L

0,0 0,1 0,2 0,3 0,4 0,5

2,6-

dim

ethy

lphe

nol s

orpt

ion,

mm

ol/g

of p

olym

er

0,00

0,02

0,04

0,06

0,08

trifluoroacetate form hexafluorophosphate form trifluoromethanesulfonate form tetrafluoroborate form

Fig.2. 2,6-dimethylphenol uptake by N-methylimidazol resin in various ionic forms.

67

p-nitroaniline equilibrium concentration, mmol/L0,0 0,1 0,2 0,3 0,4 0,5

p-ni

troa

nilin

e so

rptio

n, m

mol

/g o

f pol

ymer

0,00

0,02

0,04

0,06

0,08

0,10

trifluoroacetate form hexafluorophosphate formtrifluoromethanesulfonate formtetrafluoroborate form

Fig.3. p-nitroaniline uptake by N-methylimidazol resin in various ionic forms.

p-nitrophenol equilibrium concentration, mmol/L0,0 0,1 0,2 0,3 0,4 0,5

p-ni

trop

heno

l sor

ptio

n, m

mol

/g o

f pol

ymer

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

trifluoroacetate form hexafluorophosphate form trifluoromethanesulfonate form

Fig.4. p-nitrophenol uptake by N-methylimidazol resin in various ionic forms.

68

The distribution coefficients are in the range between 100 and 500, what makes these resins usable. In the presentation the possible mechanism of organic substances uptake will be discussed as well as kinetics of sorption and desorption.

REFERENCES

1. B. N. Kolarz, M. Wojaczyńska, A.W. Trochimczuk, Makromol. Chem., 194(1993)1299

2. A. W. Trochimczuk, M. Streat, B. N. Kolarz, React. Funct. Polym., 46(2001)259 3. B. N. Kolarz, A. W. Trochimczuk, M. Wojaczynska, M. Drewniak, Angew.

Makromol. Chem., 217(1994)19 4. B. N. Kolarz, D. Jermakowicz-Bartkowiak, A. W. Trochimczuk, Eur. Polym. J.,

34(1998)1191

69

REMOVAL OF CHROMIUM (VI) FROM AQUEOUS SOLUTION BY L OW COST ADSORBENT

Dilek Duranoğlu GÜLBAYIR, Ülker BEKER

Yıldız Technical University, Chemical Engineering Department

Davutpaşa Campus, Esenler 34210, Istanbul-TÜRKĐYE

The removal of heavy metals from wastewater is important since they cause a threat for the environment. Chromium is one of the well-known heavy metal contaminants and its compounds are widely used in metal alloys, metal coating, textile, paint and pigments industries. The hexavalent form is more toxic than the trivalent form and does not precipitate directly by using conventional precipitation methods [1]. Ion exchange, electrodialysis, reverse osmosis, solvent extraction, electrochemical precipitation and activated carbon adsorption have also been suggested for the removal of hexavalent chromium. Adsorption by using low cost adsorbent is an attractive method because of its cost and possible regeneration. Well-developed porous structure and surface functional properties makes it is very attractive for heavy metal sorption in low concentrations. Various agricultural wastes have been evaluated to produce low cost activated carbon recently [2-6] The nature of precursors, carbonization methods and activation processes affects activated carbon properties obtained.

The objective of this study was to produce low cost activated carbon and determine its Cr(VI) sorption capacity by varying initial Cr (VI) concentration, adsorbent dose and solution pH.

EXPERIMENTAL

Peach stones, which are one of the agricultural wastes in Turkey, were used as precursor for preparation of low cost activated carbon. They were pretreated by using successively alkali and acid treatment. Pretreated samples were then rinsed to remove excess of acid. They were carbonized in a tube furnace by using steam flow at 1073 K after drying in an oven at 383K for 24h to remove humidity. Obtained carbon samples were rinsed with hot distilled water till neutral pH. Samples were powdered and dried at 378K before using sorption experiments. Chromium (VI) adsorption capacities of the carbon sample were investigated in batch systems. Adsorption studies were conducted at different pH (2, 4, 6, 8) and different initial concentrations. During the batch sorption experiments the pH of the solution was kept constant by adding HCl and NaOH solutions. Equilibrium Cr(VI) concentrations were determined by using Analytic Jena Specord 40 UV Spectrophotometer.

The properties of activated carbon samples were determined by using various analytical methods like differential titration methods described by Boehm

70

[7], pH titration methods described by Helfferich [8] and zeta potential measurements. The specific surface area, N2 adsorption isotherms and pore volumes were obtained from nitrogen adsorption data at 77 K.

RESULTS AND DISCUSSION

N2 adsorption isotherm shows that activated carbon sample has microporous

structure. Steam activation and pretreatment were effective on development of surface area and micropore volume of the activated carbon samples. The point of zero charge (PZC) and the isoelectric point (IEP) of activated carbon sample are about 7.6 and 2.0, respectively. Due to the fact that carbon surface is positively charged at pH values below the PZC, activated carbon sample prepared can be able to exchange anions till the pH 7.6.

Cr(VI) sorption capacity of carbon sample was strongly depend on pH of the solution. As a result of sorption studies, activated carbon sample has effective Cr(VI) removal at pH 2. This result also has been supported by literature [2,6,9,10].

The increase of Cr(VI) sorption capacity at low pHs could be explain that the electrostatic attraction between positively charged groups of carbon surface and HCrO4

- ions. Cr(VI) sorption capacity was decreased because of decreasing electrostatic attraction and competitiveness between HCrO4

- anions and OH- ions by increasing pH.

0

20

40

60

80

100

120

0 1 2 3 4 5 6Equilibruim Cr(VI) concentration, mg/L

Cr(

VI)

so

rptio

n c

apac

ity,

mg

/g

pH2

pH4

pH6

pH8

0

20

40

60

80

100

120

140

160

0 5 10 15 20 25 30 35Equilibruim Cr(VI) concentration, mg/L

Cr(

VI)

so

rptio

n c

apac

ity,

mg

/g

pH2

pH4

pH6

pH8

Fig.1. Cr(VI) sorption capacity of the activated carbon sample at 5ppm initial concentration

Fig.2. Cr(VI) sorption capacity of the activated carbon sample at 30ppm initial concentration

According to the PZC value of carbon sample, carbon surface is negatively

charged at pH 8 and minimum sorption capacity was obtained at this pH. Consequently, the possible Cr(VI) removal mechanism is thought as anion exchange. In addition, Cr(VI) sorption capacity of the carbon sample increased with the initial chromium concentration. As a conclusion, an indigenous, low cost

71

activated carbon can be developed as an effective sorbent to remove Cr (VI) ions from aqueous solutions with relatively high sorption capacity.

REFERENCES

1. J. Hu, G. Chen, I. M. C. Lo, Water Research., 39(2005)4528 2. U. K. Garg, M. P. Kaur, V. K. Garg, D. Sud, J. Hazardous Mater., 140(2007)60 3. K. Mohanty, M. Jha, B. C. Meikap and M. N. Biswas, Chem. Eng. Sci., 60(2005)3049 5. G. Cimino, R. M. Cappello, C. Caristi, G. Toscano, Chemosphere, 61(2005)947 6. Y. Guo, J. Qi, S. Yang, K. Yu, Z. Wang, H. Xu, Mater. Chem. Phys.,

78(2002)132 7. K. Ranganathan, Bioresource Technol., 73(2000)99 8. H. P. Boehm, Advances in Catalyst, Academic Press, New York, 16(1966), pp.

179-274 9. F. Helfferich, Ion Exchange, Dover Publications, New York, 1995 10. Y. Selomulya, V. Meeyoo, R. Amal, J. Chem. Technol. Biotechnol., 74(1999)111 11. Guo, J. Qi, S. Yang, K. Yu, Z. Wang, H. Xu, Mater. Chem. Phys., 78(2002)132

REMOVAL OF NICKEL FROM AQUEOUS SOLUTION BY USING FIXED BED ION EXCHANGE COLUMN

SEMIHA MURAT, DURANOĞLU GÜLBAYIR, D., BEKER, Ü

Yıldız Technical University, Chemical Engineering Department

Davutpaşa Campus, Esenler 34210, Istanbul-TÜRKĐYE

In this study, commercial active carbon namely Chemviron CPG-LF was used for the removal of Nickel from aqueous solution at pH 5. Carbon sample (ACS) was oxidized by using acid and electrochemical activation treatment to increase its heavy metal sorption capacity for comparison ith as-received sample. The surface reactivity and functional group distribution of the activated ACSs were investigated using electrophoretic mobility measurements, pH titrations and FTIR measurements. The effect of activation methods on the Nickel adsorption capacity were investigated at pH 5.0 in an ion exchange column to evaluate both the effects of activation methods on the formation of surface oxygen complexes and to compare adsorption capacity of ACSs on adsorption of Nickel. Furthermore, regeneration studies were accomplished in order to determine the best regeneration concentration to remove Nickel from ACCs.

INTRODUCTION

Industrialization and together with the population growth reduced the clean water resources. Industries generate highly toxic and carcinogenic heavy metal contaminations if they enter the food chain and also important environmental problems can result. Waters containing Nickel compounds also cause a serious problem since present a high health risk to consumers but also are non-biodegradable toxic heavy metals and may cause dermatitis and allergic sensitization [1,2] even at low concentrations. According to the WHO, the maximum permissible concentration of nickel in drinking water should be less than 0.1 mg/l [3]. Oxidation, precipitation, adsorption, ion exchange and solvent extraction methods have been used to remove Nickel from aqueous solutions. Adsorption methods are attractive since they are energy conservatives and affect the competitive and complex process of adsorption from diluted solutions. Most of polymeric adsorbents are desirable because of their high surface area and pore structures for the removal of organic compounds. Interest for a low cost and easily available adsorbent has led to the evaluation of materials such as agricultural and industrial by-products to production of activated carbon as adsorbents. In this work, the main objective of this research is to explore the effect of activation methods of carbon for Nickel removal.

73

EXPERIMENTAL

The reference carbon (Calgon CPG-LF) was provided by Calgon and is made from bituminous coal [4]. Introduction of different oxygenated functional groups onto the carbon surface was conducted both by means of nitric acid activation at 90ºC and electrochemical activation by using 0.1 M KCl as an electrolyte solution at 25ºC, 45ºC and 60ºC.

Nitric acid oxidation of the active carbon sample was carried out at 90ºC. Dry samples were added to a 1L three-necked flask, equipped with stirrer, condenser, dropping funnel, and heating mantle. Thereafter, 20% (v/v) nitric acid was added slowly through the funnel. The reaction was stopped after 8 h and 12 h time intervals (these samples were designated as ACS8h and ACS12h, respectively) and samples taken were washed with distilled water. Conversion of the adsorbent into the hydrogen form was accomplished by treatment with a 0.1 N solution of hydrochloric acid followed by a final wash with distilled water. The adsorbent material was dried overnight in an oven at 105ºC. The carbon was kept in a dessicator for further studies.

The electrochemical cell was immersed in a thermostatically controlled water bath. A 1g sample of activated carbon produced was placed into to plastic column and immersed in 0.5M KCl for 3 h time interval at 25ºC (these sample was designated as EA3h). The bottom place of plastic column was supported by filter paper and anode and cathode (platinium) were placed inside and bottom side of the column, respectively. Oxidation was carried out by applying in the oxidation of carbonaceous material a current of 1Am. In this research, many oxygen-containing groups were used as the criterion to determine the experimental conditions. The activated carbons obtained were protonated with 0.1 M HCl followed by a water rinse until the pH of the rinse water was around 6. The activated carbons were dried at 110ºC before use. Column experiment was performed PE column (i.d. 0.6 cm, length 6.0 cm) filled with 0.3 gms granular samples. A flow controller was used to control the inlet flow rate. Nickel concentration was 1 ppm and ion (3), flow rate (3.0 cm3 min-1) and ACS bed height (1 cm) with particle size of +0.1 to -0.50 mm in the column. The effluent was collected from the column at regular time intervals and Nickel concentration was measured.

RESULTS AND DISCUSSION

Surface chemistry of activated carbon has an important role since adsorption of heavy metals is favored by the presence of oxygen-containing functional groups and electrostatic attraction for these groups. These groups can be increased through activation of carbon adsorbents by using chemical and physical activation methods. The activated samples through activation processes have the most intense peaks covered the absorption bands corresponding to all the functional groups revealed by titration.

74

The approximate FTIR band assignments indicated the presence of carbonyls, carboxyls, lactones and phenols. According to FTIR spectra and the literature (5), activated carbons have different surface functional groups such as phenolic O-H, C-H (stretching), carboxylic acids (at 2849-2961 cm-1), carboxylic acids, lactones (at 1717-1747 cm-1), quinones (at 1578-1637 cm-1), carboxyl-carbonates (at 1390-1459 cm-1 and 1115-1167 cm-1). There is a band for all samples between 3425 and 3442 cm-1 for adsorbed water which masked the other functional groups of carbon structure. FTIR and Boehm’s results showed that the carbons both activated with nitric acid and electrochemical activation can be regarded as prospective cation-exchangers for the removal of heavy metals from water solutions.

Fig.1. Mini-column breakthrough result for nickel removal The pH titration results also suggest that increasing activation period caused

an increase in concentration of both carboxyl and phenolic type groups for activation. The pHPZC values also decreased with the severity of oxidation treatment and approached the pHIEP values. This suggests that the highly oxidised samples are more uniformly oxidised.

Fig.1 displays a representative breakthrough curve for the series of carbons oxidised using both acid and electrochemical oxidation. Nickel sorption data indicates that according to degrees of surface oxidation, the oxidised activated carbon by using electrochemical activation has the higher sorption capacity for Nickel in comparison with acid activation method under identical sorption conditions (Figure 1). A linear correlation was found between Nickel sorption and the concentration of phenolic groups present in both electrochemical and acid oxidised CPG-LF carbons. Electrochemically oxidised carbons also showed a strong dependence between Nickel sorption and the concentration of phenolic groups

0

0,2

0,4

0,6

0,8

1

1,2

0 1000 2000 3000 4000 5000 6000 7000

Bed volumes passed, mL

Effl

uent

conce

ntra

tion, C

o/C

i

Unoxidized CPG-LF

ACS8h

ACS12h

EA3h

75

present within the samples. According the regeneration results, better regeneration conditions was obtained by using 10% HCl trelated to 5% HCl.

REFERENCES 1. F. A. Abu Al-Rub, M. Kandah, N. Al-Dabaybeh, Eng. Life Sci., 2(2002)111 2. F. A. Abu Al-Rub, M. Kandah, N. Al-Dabaybeh, Sep. Sci. Technol.,

38(2)(2003)483 3. US EPA, Guidance Manual for Electroplating and Metal Finishing Pretreatment

Standards, 1984 4. Calgon, Granular carbon, Technical bulletin 23-142a, Calgon Carbon

Corporation, Pittsburgh, PA, USA, 1987 5. J. L. Figueiredo, M. F. R. Pereira, M. M. A. Freitas, J. J. M. Orfao, Carbon,

37(1999)1379

76

EXTRACTION OF METAL CATIONS WITH CALIX-CROWNS

Jerzy GĘGA

Częstochowa University of Technology, Department of Chemistry, Al. Armii Krajowej 19, 42-200 Częstochowa, Poland;

e-mail: gega@mim.pcz.czest.pl A wide variety of macrocyclic ligands able to interact with neutral species, cations, and anions are known. Among them calixarenes and their derivatives have received considerable attention in recent years. The molecular structure of such compounds allows to bound of guest substrates within the hydrophobic bowl-cavity of calixarene through non-covalent interactions or outside the cavity by functionalities of upper or lower rim [1,2]. The first synthesis of calixarene compound was made by A.Baeyer in 1872 by heating of formaldehyde with phenol [3]. The cyclic structure of the reaction product was confirmed in 1950’s by J. W. Comworth and coworkers [4]. The presently accepted name of “calixarene” was proposed by C. D. Gutsche in 1970’s (Greek “calyx” means a chalice and the word “arene” indicates the presence of aryl rings in the molecule) [5]. One of the most interesting feature of calixarene-based cation ligands is that the metal ions complexation properties depend not only on the nature of the binding groups attached to the platform, but also on their stereochemical arrangements, which is determined by the molecule conformation. It is a known fact that the introduction at the lower rim of calix[4]arenes an alkyl group larger than ethyl or polyether chain cause the freezing of the ring inversion process giving four different stereoisomers (e.i. cone, partial-cone, 1,3-alternate and 1,2-alternate) [2]. Among the different calixarenes, especially calixarene-crown ethers are an important type of ligands for spherical metal ion complexation [1,2,6]. It has been shown that efficiency and selectivity of metal ion extraction by calix[4]arene-crown ethers is controlled by the polyether ring size, as well as the conformation of the molecule (Fig.1) [7]. It has also been reported that the efficiency and selectivity of metal ions extraction can by influenced by variation of para-substituents on the calixarene scaffold [8]. Although all calixcrowns-5 are selective for potassium, and all calixcrowns-6 for cesium, the efficiency and selectivity of complexation are strongly depend on the molecule conformation. It has been shown that K+/Na+ selectivity for crowns-5 and Cs+/Na+ selectivity for crowns-6 decrease in the order 1,3-alternate > partial cone > cone

77

HOOHO

O

O

O

O

O

HO

OH

O

O

O

O

O

O

HO OH

O

O

O

O

O

O

Cone Partial-cone 1,3-Alternate

Fig.1. Examples of conformationally fixed isomers of calix[4]crown-6

emphasizing that the preorganisation of the ligand in the conformation preferred for complexation is a crucial point for obtaining ion selectivity [2]. In particular, the some of calyx[4]crowns-5 in the 1,3-alternate conformation show the higher K+/Na+ selectivity ever the valinomycin – the best potassium selective ionophore known. The high selectivity of calixrowns-6 for Cs+ over Na+ allowed to apply these compounds for the removal of long-lived radionuclide 137Cs from nuclear waste, where sodium nitrate and nitric acid are present at a much higher concentration than cesium nitrate [2,6]. Bartsch and coworkers reported the synthesis of di-ionizable p-tertbutylcalix[4]arene-crown-6 ligands conformationally locked in the cone, partial-cone and 1,3-alternate conformations as the alkaline earth ion extractants [8,9]. Upon ionization the two acidic groups provided the requisite anions to form electroneutral extraction complexes. This avoided the need to transfer anions from the aqueous phase into the organic phase in the solvent extraction process and thereby markedly enhanced the efficiency of metal extraction from metal solutions of metal chlorides, nitrates or sulfates. For competitive solvent extraction of alkaline earth ions from the aqueous solutions into chloroform, the cone conformers exhibited high extraction efficiency and selectivity for Ba2+ over Mg2+, Ca2+ and Sr2+. The 1,3-alternate conformers were found to be weaker extractants, but retained high Ba2+ extraction selectivity. On the other hand the partial-cone conformers displayed very poor extraction capability. It was found that the spatial relationship between the ionziable groups and the crown ether ring has a very important influence on the extraction efficiency and selectivity. The cone conformation, in which the two ionized groups were located on both sides of polyether ring bound divalent metal ion, was the most energetically favorable for divalent metal ion extraction [9]. Di-ionizable calix[4]arene-crown-6 ligands showed alkaline earth metal ion extraction efficiency and selectivity decreasing in the order of

cone > 1,3-alternate >> partial-cone On the other hand it was foun that p-H-calix[4]arene compounds indicated greater flexibility than in analogues with p-tert-butyl substituents. Due to the generally lower alkaline earth metal ion extraction efficiency and selectivity observed for the

78

p=H=compounds is attributed to this greater ligand flexibility [8]. It confirms the very important influence of ligand preorganisation on extraction efficiency.

REFERENCES

1. C. D. Gutsche, Calixarenes Revisited, The Royal Society of Chemistry, Cambridge 1998

2. L. Mandolini, R. Ungaro (Eds.), Calixarenes in Action, Imperial College Press, London 2000

3. A. Baeyer, Ber., 5(1872)1094 4. J. W. Comworth, H. P. D’ Arey, G. A. Nicholls, R. J. Rees, J. A. Stock, Br. J.

Pharmacol., 10(1955)73 6. C. D. Gutsche, R. Muthukrishnan, J. Org. Chem., 43(1978)4905 7. G. J. Lumetta, R. D. Rogers, A. S. Gopalan, (Eds.), Calixarenes for Separation,

American Chemical Society, Washington, DC, 2000 8. A. Casnati, A. Pochini, R. Ungaro, C. Bocchi, F. Ugozzoli, R. J. M.Egberink, H.

Struijk, R. Lugtenberg, F. de Jong, D. N. Reinhoudt, Chem.-Eur.J., 2(1996)436 9. H. Zhou, D. Liu, J. Gega, K. Surowiec, D. W. Purkiss, R. A. Bartsch, Org.

Biomol. Chem., 5(2007)324 10. H. Zhou, K. Surowiec, D. W. Purkiss, R. A. Bartsch, Org. Biomol. Chem.,

3(2005)1676

79

SORPTION OF HEAVY METAL IONS FROM AQUEOUS SOLUTIONS IN THE PRESENCE OF COMPLEXING AGENTS

ON POLYACRYLATE ANION EXCHANGERS

Dorota KOŁODYŃSKA, Halina HUBICKA, Zbigniew HUBICKI

Department of Inorganic Chemistry, Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie-Sklodowska Sq.2. 20-031

Lublin, Poland, tel.: +48 (81) 5375736; Fax: +48 (81) 533 33 48, e-mail address: kolodyn@poczta.onet.pl

Aminopolycarboxylic acids such as ethylenediaminetetraacetic (EDTA),

nitrilotriacetic (NTA), diethylenetriaminepentaacetic (DTPA), hydroxyethylethylenediaminetriacetic (HEDTA), iminodiacetic (IDA) and iminodisuccinic acid (IDS) (Fig.1) are widely used for industrial, pharmaceutical and agricultural purposes including, among others, metal, textile, leather, rubber, food, cosmetic, paper and textile production. [1,2].

Fig.1. Structural formulae of the complexing agents – EDTA, NTA, DTPA, HEDTA, IDA and IDS

Synthetic chelating agents form strong and water soluble complexes with

various cations, but (except for NTA) they are almost resistant to biodegradation. Therefore their concentrations have often increased in some aquatic systems to unacceptable levels. There is also much interest in changing them by a new generation of chelates of improved biodegradability such as EDDS or IDS (Fig.1). Additionally, in the environment chelating agents have some undesired features such as the remobilization of radionuclides and toxic heavy metal ions from sediments and soils [3,4].

HOOC N

N

COOH

COOH

HOOC ED

HOOC

N

HOOC

COOH

NT

HOOC N

N

COOH

N

HOOC

COOH

COOHDT

H N

COOH

COOH

ID

HOOC N

N

COOH

HOOC

OH

HE

HOOC

HOOC

COOH

COOHN

H

IDS

80

NH

N

CH3

CH3

+

O

CH3

CH

Typical chemical precipitation methods (e.g. OH- and S2-), the most economical for the treatment of effluents containing heavy metal ions in the presence of strong chelating agents such as EDTA, NTA are ineffective. For treatment of these industrial wastewaters, when these metals are present as anionic complexes, the anion exchange plays a main role. In this case sorption, separation, removal and recovery of heavy metal ions are achieved by variation in parameters affecting the sorption process. The kind of applied anion exchanger is also a very important factor.

Polyacrylate anion exchangers are widely applied in water purification processes. They are characterised by favourable mechanical properties and high resistance to the osmotic shock. Polyacrylate anion exchangers possess unique physical and chemical properties, high ion exchange capacity, perfect physical resistance, quick kinetic exchange, very high resistance to organic impurities and greater basicity than polystyrene anion exchangers. They can be applied for deacidification, deionization and desalination of water where the removal of strong mineral acids and adsorption of organics are desired. Amberlite IRA 458 the strongly basic, gel polyacrylate anion exchanger has been applied to remove arsenate from drinking water as well as cyanide complexes of Ni(II), Fe(III), Cu(II), Co(II) from the effluent of metallurgical processing plants [5,6]. Amberlite IRA 68 the weakly basic, gel and Amberlite IRA 958 the strongly basic, macroporous anion exchangers are used for removal of heavy metal complexes particularly of Pb(II), Co(II), Cu(II), Ni(II) with EDTA from the effluent of metallurgical processing plants [7,8]. The structures of the strongly basic polyacrylate anion exchanger Amberlite IRA 458 and the weakly basic anion exchanger of this type Amberlite IRA 67 are presented in Fig.2.

Fig.2. Structure of the polyacrylate anion exchangers Amberlite IRA 458 and Amberlite IRA 67

This paper investigates the use of the commercially available polyacrylate anion exchangers Amberlite IRA 458, Amberlite IRA 958 and Amberlite IRA 67 for the removal of heavy metal ions Cu(II), Zn(II), Co(II), Ni(II), Pb(II), Cd(II) and Fe(III) in the presence of the complexing agents EDTA and NTA.

The solutions of metal complexes with EDTA and NTA were prepared by dissolving equimolar amounts of each metal chloride/nitrate in the EDTA (at pH

AMBERLIT AMBERLIT

NH

NCH3

CH3

O

CH

81

4.6) or NTA (at pH 4.0) solutions. The initial concentration of metal ions was 10-3 M, which is located within the level of real effluents such as planting waste waters. The experiments were carried out at pH values without adjustment. For anionic complexes of these heavy metals the recovery factors (%R) were determined by means of the static method (0.5 g of appropriate dry anion exchanger was placed in a 100 cm3 stoppered conical flask containing 50 cm3 of complexed heavy metal ion solution and shaken at the constant temperature - 25oC in the three parallel series). After equilibrium, the pH was measured with a Radiometer pH meter (Model PHM 82). The concentrations of Cl-/NO3

- ions were not determined. The contents of each metal in the raffinate and eluate were determined by the AAS method (Varian SpectrAA- 880).

As follows from the literature data [7,8] the capacity of polyacrylate anion exchangers like Amberlites for metal ions complexed with aminopolycarboxylic acids depends on the pH value. At pH about 2 where the dominant species are monovalent complexes, the removal of metal complexes is insignificant. It was also stated that the presence of calcium complexes with EDTA in the form of divalent species [Ca(edta)]2- does not influence the heavy metal removal.

Taking into consideration the above statements, the studies of sorption of Cu(II), Zn(II), Co(II), Ni(II), Pb(II), Cd(II) and Fe(III) complexes with EDTA on polyacrylate anion exchangers in the pH range from 2.0 to 6.0 using the static method, at the constant phase contact time which is 6 h were carried out. With the increasing pH of the solution, the values of recovery factors (%R) of metal ions on the anion exchangers Amberlite IRA 458, Amberlite IRA 67 and Amberlite IRA 958 increase and reach the plateau at pH above 5 (these data are not presented). Therefore in the next stage, the investigations of sorption by the static method depending on the phase contact time were carried out in the 0.001M M(II)/(III)-0.001M EDTA and 0.001M M(II)/(III)-0.001M NTA systems. The values of recovery factors (%R) of the complexes determined for the anion exchangers in question are presented in Fig.3.

As follows from the comparison of the obtained results (Fig.3) in the case of sorption of Cu(II), Zn(II), Co(II), Ni(II), Pb(II) and Cd(II) complexes with EDTA the recovery factors assume the values in the range 80-100% and are slightly differentiated for all the anion exchangers in the investigations. The equilibrium state of sorption for these anion complexes occurs at the ion exchanger–solution phase contact time about 30 min. However, the recovery factors of Fe(III) complexes are lower (values below 70 %) which confirms that the complexes of [M(edta)]- type exhibit lower affinity for polyacrylate anion exchangers in comparison to that of [M(edta)]2- type.

82

Fig.3. Comparison of the recovery factor (% R) values for Cu(II), Zn(II), Co(II), Ni(II), Pb(II), Cd(II) and Fe(III) complexes with EDTA and NTA on the polyacrylate anion exchangers Amberlite IRA 458, Amberlite IRA 958 and Amberlite IRA 67

0 60 120 180 240 3000

20

40

60

80

100

Amberlite IRA 458

Cu(II)-NTA Zn(II)-NTA Co(II)-NTA Ni(II)-NTA Pb(II)-NTA Cd(II)-NTA Fe(III)-NTA

%R

t [min]

0 60 120 180 240 3000

20

40

60

80

100

Amberlite IRA 67

Cu(II)-NTA Zn(II)-NTA Co(II)-NTA Ni(II)-NTA Pb(II)-NTA Cd(II)-NTA Fe(III)-NTA

%R

t [min]

0 60 120 180 240 3000

20

40

60

80

100

Amberlite IRA 958

Cu(II)-NTA Zn(II)-NTA Co(II)-NTA Ni(II)-NTA Pb(II)-NTA Cd(II)-NTA Fe(III)-NTA

%R

t [min]

0 60 120 180 240 3000

20

40

60

80

100

Amberlite IRA 458

Cu(II)-EDTA Zn(II)-EDTA Co(II)-EDTA Ni(II)-EDTA Pb(II)-EDTA Cd(II)-EDTA Fe(III)-EDTA

%R

t [min]

0 60 120 180 240 3000

20

40

60

80

100

Amberlite IRA 67

Cu(II)-EDTA Zn(II)-EDTA Co(II)-EDTA Ni(II)-EDTA Pb(II)-EDTA Cd(II)-EDTA Fe(III)-EDTA

%R

t [min]

0 60 120 180 240 3000

20

40

60

80

100

Amberlite IRA 958

Cu(II)-EDTA Zn(II)-EDTA Co(II)-EDTA Ni(II)-EDTA Pb(II)-EDTA Cd(II)-EDTA Fe(III)-EDTA

%R

t [min]

83

In the case of heavy metal complexes with NTA the values of the recovery factors are lower but more differentiated. The affinity series of these complexes can be arranged as follows: for the strongly basic anion exchangers Amberlite IRA 458: Cu(II) > Fe(III) > Ni(II) = Pb(II) = Zn(II) > Co(II ) > Cd(II); Amberlite IRA 958 Cu(II) > Fe(III) > Co(II )> Ni(II) > Pb(II) > Zn(II ) > Cd(II) and the weakly basic one: Amberlite IRA 67 Cu(II) > Cd(II) > Zn(II) > Fe(III) > Co(II) > Ni(II) > Pb(II). It is worth mentioning that the weakly basic anion exchanger Amberlit IRA 67, contrary to the strongly basic anion exchangers Amberlite IRA 458 and Amberlite IRA 958 has the highest affinity for Cd(II) complexes with NTA. The data obtained indicate that the sorption of heavy metal complexes with aminopolicarboxylic acids is effective and provide the advantage of simultaneous removal of these metals and organic ligands.

REFERENCES

1. T. P. Knepper, Trends in Analytical Chem., 22(2003)708 2. T-T. Lim, P-Ch. Chui, K-H. Goh, Chemosphere, 58(2005)1031 3. S. Metsärinne, T. Tuhkanen, R. Aksela, Chemosphere, 45(2001)949 4. P. W. Jones, D. R. Williams, Appl. Radiataion and Isotopes, 54(2001)587 5. P. A. Riveros, Hydrometallurgy, 33(1999)43 6. A. B. Nesbitt, F. W. Petersen, Sep. Sci. Technol., 30(1995)2979 7. R-S. Juang, L-D.Shiau, Ind. Eng.Chem. Res., 37(1998)555 8. M. R. Dudzińska, D. A. Clifford, React. Polym., 16(1991/1992)71

84

A POROUS STYRENE DIVINYLBENZENE COPOLYMER ADSORBENT CAPABLE OF REMOVING MIDDLE

MOLECULAR WEIGHT MOLECULES FROM BLOOD WHILST SIZE EXCLUDING ALBUMIN

I. ROCHE1*, D. J. MALIK1, G. L. WARWICK2, N. A. HOENICH3, C. WEBB1, D.

J. WILLIAMS4

1Department of Chemical Engineering, Loughborough University, Loughborough, LE11 3TU, United Kingdom

2 Department of Nephrology, Leicester General Hospital, Leicester LE5 4PW, United Kingdom

3 Department of Nephrology, University of Newcastle-upon-Tyne, The Medical School, NE2 4HH, United Kingdom

4 Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU, United Kingdom

*i.roche@lboro.ac.uk

INTRODUCTION Haemodialysis is routinely used for the removal of small molecular weight

toxins (e.g. urea and creatinine) and for the regulation of water. However, inadequate removal of middle molecular weight molecules (MMW, 10-20 kDa) is of clinical concern. Patients on haemodialysis have elevated concentrations of MMW molecules including β2-microglobulin (11.8 kDa, concentration around 50mg/l), cytokines (e.g. IL1-β, MW 18kDa, concentration around 0.5µg/l) as well as advanced glycosylated end-products and advanced lipoxygenated end-products. It is well documented in literature that retention of middle molecular weight molecules are implicated in the long term complications of haemodialysis [1]. Current haemodialysis membranes have a molecular weight cut-off of around 50 kDa however, due to the adsorption of blood proteins on the dialysis membrane (fouling), the removal of MMW solutes due to diffusion remains poor. Recent research [2] has focused on the possibility of using structured porous adsorbents to remove the solutes whereas the membrane carries out the function of clearance of small MW solutes and water regulation.

The research reported in this paper looks at the characterisation of a mesoporous polymer adsorbent (pore structure tailored during suspension polymerisation) for the selective removal of lysozyme (β2-M surrogate marker, MW 14kDa) whilst selectively excluding albumin (MW 69kDa). The use of any adsorbent based system is severely restricted by the fact that the albumin is present in blood at a concentration of 40g/l whereas the concentration of β2-M is three

85

orders of magnitude smaller. Hence, if the solutes have an equal affinity for the surface, albumin would swamp the adsorbent surface resulting in inefficient adsorption. By tailoring an adsorbent that effectively size excludes albumin, an attempt has been made to overcome this problem. The study looks at the influence of pore structure on the transport behaviour of proteins within the polymer bead. In addition the effects of a binary solute system containing both albumin and lysozyme have been evaluated to see if the presence of albumin influences the uptake kinetics or equilibrium adsorption capacity of lysozyme on the adsorbent.

MATERIALS AND METHODS

XAD4, a commercial styrene divinylbenzene copolymer (Rohm & Haas)

was purchased for comparison with a styrene divinylbenzene copolymer resin prepared in-house for this study. The pore structure of the two adsorbents were measured using nitrogen porosimetry and are reported in Fig.1. The kinetics of adsorption of lysozyme and albumin from a Hepes buffer solution on the two adsorbents were studied as single solute and binary systems using a stirred batch reactor with samples taken at regular intervals. Influence of degree of mixing and particle size were also evaluated. Protein concentrations were measured using a reverse phase HPLC column system equipped with a diode array detector.

RESULTS AND DISCUSSION The tailored adsorbent (CW1) synthesised in-house possesses a surface area

of 100 m2/g within the pore size range 2-10 nm (see table in Figure 1). The pore size distribution shows absence of pores larger than 10nm (see Figure 1). The XAD4 adsorbent possesses nearly 3 times as much surface area as CW1 in the 2-10nm range but possesses 60 m2/g of surface area above 10nm. This Results in XAD4 having over 21 m2/g of area available for Albumin adsorption compared with just 0.5 m2/g in CW1.

The CW1 polymer demonstrated effective size exclusion of albumin (from a single solute system) whilst allowing lysozyme access within the adsorbent interior. The XAD4 adsorbent allowed albumin access to the internal pore structure with albumin uptake around 3.4mg/g after 24 hours. Uptake of albumin onto CW1 was around 0.3 mg/g (reached after 90mins of contact) suggesting size exclusion of the protein. As expected, the tighter pore structure of the CW1 results in slower uptake of lysozyme although both materials showed adsorption uptake in excess of 3.4mg/g after 24 hours (see Fig.2). The results also show the influence of external (influence of external agitation) and internal mass transfer effects (influence of particle size) on protein adsorption kinetics. This data shows that the slower adsorption kinetics of the CW1 material would require engineering of smaller sized particles to improve adsorption kinetics without requiring excessively long clinical haemoperfusion treatment times (this would also entail consideration of the design of the adsorption

86

column in order to overcome effects such as pressure drop, a consequence of the reduction in particle size).

0

10

20

30

40

50

60

70

80

90

10 100 1000

Pore Width (A)

Incr

emen

tal S

urfa

ce A

rea

(m2/

g)

CW1 XAD4

0.0052950.11878100.030.18CW1

0.2060410.6623060.020.360.50XAD4

AlbuminLysozyme>500 A100 - 500 A20 - 100 A

Accessible toDFTBET

Pore Volume (cm3/g)

0.531.830.034.4287.9CW1

21.35627133.40.2450.88222.53XAD4

AlbuminLysozyme>500 A100 - 500 A20 - 100 A

Accessible toDFTBET

Pore Surface Area (m2/g)

Fig.1. Pore size distributions of XAD4 and CW1 (incremental surface area as a function of pore size)

0

50

100

150

200

250

0 50 100 150 200 250 300 350 400 450 500

Time (mins)

Con

cent

ratio

n (m

g/l)

XAD4 Lysozyme CW1 Lysozyme XAD4 Albumin CW1 Albumin

Fig.2. Adsorption kinetics of proteins (lysozyme and albumin) from single solute systems

Adsorption from a binary system containing both lysozyme (starting

concentration 100mg/l) and albumin (starting concentration 200mg/l) as competing proteins demonstrates that the presence of albumin does not influence the uptake of lysozyme on CW1 (see Fig.3). Thus albumin seems to be effectively rejected by the adsorbent whereas lysozyme can penetrate the internal pore structure of the particle and be removed by adsorption.

87

0

20

40

60

80

100

120

0 200 400 600 800 1000 1200 1400 1600

time (mins)

Con

cent

ratio

n (m

g/l)

with Albumin without albumin

Fig.3. Comparison of the presence of albumin as a competing protein on the adsorption dynamics of lysozyme on adsorbent CW1

CONCLUSIONS

A haemoadsorbent for the selective adsorption of MMW solutes based on a

size exclusion principle may offer the possibility of a treatment for patients on long term haemodialysis. This paper presents preliminary evidence that tailoring of the internal pore structure of a styrene divinylbenzene copolymer may facilitate the size exclusion of the competing protein albumin whilst permitting MMW molecules such as Lysozyme to adsorb to the polymer. A consequence of the tighter pore structure in CW1 is the reduction in the lysozyme uptake kinetics due to the absence of larger transport pores present in XAD4.

ACKNOWLEDGEMENTS

The authors wish to acknowledge the financial support of EPSRC grant

EP/C517660/1 in order to carry out this work.

REFERENCES

1. T. Vraetz, T. H.Ittel, M. G. Van Mackelenberg, Nephrology dialysis transplantation, 14(9)(1999)2137

2. J. F. Winchester, C. Ronco, V. Kuntsevich,. Blood Purification 22 (1)(2004)73

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ENGINEERING OF THE INTERNAL PORE STRUCTURE OF POLY(STYRENE-DIVINYLBENZENE) ADSORBENTS FOR THE

REMOVAL OF MIDDLE MOLECULAR WEIGHT PROTEINS FROM BLOOD AND THE EXCLUSION OF ALBUMIN

C. WEBB, D. J. MALIK, R. G. HOLDICH

Department of Chemical Engineering , Loughborough University, Loughborough,

LE11 3TU, United Kingdom

INTRODUCTION

The removal of potentially harmful molecules from blood is an important area of research. Initial work has focused around the need to remove middle molecular weight proteins from the blood of long term dialysis patients. A number of the middle molecular weight molecules have been identified as having detrimental health implications (e.g. β2-microglobulin) and are not removed during current dialysis treatment. As research into this field has progressed other potential applications have become apparent, these include the treatment of acute kidney failure, sepsis and drug overdose.

To remove these middle molecular weight proteins non-specific adsorption using poly(styrene-divinylbenzene) polymer adsorbents has been investigated [1]. There is one major concern to be addressed in the removal of these middle molecular weight proteins, albumin a blood protein is present in significantly higher concentrations than the middle molecular weight proteins. This will mean that there will be a greater driving force for the removal of albumin than the middle molecular weight proteins assuming their affinity to the adsorbent is the same. To reduce this problem the internal pore structure of the poly(styrene-divinylbenzene) adsorbents could be tailored to exclude albumin.

The generation of porous poly(styrene-divinylbenzene) adsorbents has been investigated by a number of researchers [2-5] and a comprehensive review has been compiled by Okay [6]. Polymerisation is carried out using the suspension polymerisation technique where the monomer phase is dispersed in an aqueous phase containing stabilisers (e.g. poly(vinyl-alcohol)). This produces stabilised droplets of monomer which can then be polymerised to form spherical polymer beads.

To generate internal porosity within the polymer beads a porogen (also referred to as a diluent) must be added to the monomers, these porogens are inert solvents, which while playing no part in the polymerisation reaction effect the porous structure generated. Three types of porogen are available, good porogens, bad porogens and polymeric porogens. Each will effect the pore structure generated during polymerisation differently. Simply the better the solvent the smaller the

89

majority of the pores that are generated will be, good solvents producing materials with the smallest pores and polymeric porogens producing materials with the largest pores. Other factors affecting the porosity include temperature, polymerisation initiator type and concentration and crosslinking degree. By altering these parameters pore structure should be able to be engineered to exclude albumin.

Albumin has a molecular weight of 69 kDa and has an approximate diameter of 80 Å an example of a middle molecular weight protein would be lysozyme with a molecular weight of 14 kDa and an approximate diameter of 25 Å. There is obviously a significant difference in the size of these two molecules so tailoring a material to exclude albumin while allowing access to lysozyme would seem to be a realistic goal.

METHODS OF ANALYSIS

In order to assess the pore structures of the adsorbents a number of methods for analysing pore structure have been investigated. Polymer pore size distributions in the dry state were measured using a Micromeretics ASAP 2000 instrument using nitrogen as the probe molecule. Adsorption/desorption isotherms were obtained from which BET surface area, total pore volume and application of Density Functional Theory (DFT) model permitted the extraction of adsorbent pore size distributions. The main disadvantage with nitrogen porosimetry is that the material is analysed in the dry state and most polymers swell to varying degrees when exposed to solvents and in so doing change their pore structure.

In order to account for swelling effects, inverse size exclusion chromatography (ISEC) [7] may be employed. This method of pore size analysis requires a set of probe molecules and an eluent which in combination do not interact with the stationary phase, in this case poly(styrene-divinylbenzene) adsorbents. The probes and eluent employed for this material are polystyrenes of narrow polydispersity and tetrahydrofuran (THF). The probes are injected individually into a packed column of the adsorbent and the retention times of each can be evaluated to give a fraction of the pore volume accessible/inaccessible to each probe. From this size exclusion data an estimate of the maximum size of a molecule which is able to access the internal pore structure of the adsorbent can be established. ISEC has a similar limitation to nitrogen porosimetry in that the eluent and therefore the swollen nature of the polymer is fixed due to the specific conditions under which the technique is applicable.

In addition to these two techniques, freeze drying the adsorbent at low temperatures from various solvents before nitrogen porosimetry has been studied. The sublimation of frozen solvent from the adsorbent’s pores reduces the interactions between the solvent and polymer thus preserving the pore structure in the swollen state. In conjunction with the freeze drying work differential scanning calorimetry (DSC) has been used to identify the temperature required to freeze the

90

solvent in the smallest pores for each adsorbent. The DSC data also allows for qualitative comparisons of pore volumes and maximum pore size.

RESULTS AND DISCUSSION

Three materials were generated using different porogens to alter the internal pore structure of each adsorbent. Toluene as a good solvent for polystyrene will generate small pores and has been used as the basis for all the porogen mixtures. Toluene was mixed with two other porogens to determine their effect on pore structure, they are undecane and naphthalene. Table 1 shows the composition of the porogens used for the three adsorbents produced as well as the BET surface area, pore volume and DFT values for two discrete pore sizes. The normalised pore volume distributions produced from nitrogen porosimetry for the adsorbents in Table 1 can be seen in Figure 1. This shows that when dried from toluene TolNap has the lowest maximum pore cut off. TolUn and XAD-4 show very similar characteristics with larger pores and a greater fraction of their pore volumes in the pores greater than 100 Å.

Table 1. Compositions and nitrogen porosimetry data for the tree poly(styrene- divinylbenzene) adsorbents and XAD-4

Freeze drying from a number of different solvents has shown that while pore volumes and surface areas change the pore size cut off remains unchanged. This information means we can employ ISEC to determine the size of a molecule which is excluded from the internal pore structure of the adsorbents. Table 2 shows the percentage of the pore volume accessible to the 10 and 20 kDa probes and there size for each material.

Table 2. Pore volume accessibility for polystyrene probes of varying molecular weight

% Pore Volume Accessible Probe

Diameter

(Å) TolNap Tol TolUn

PS 10 kDa 55 8.0 12.6 19.7

PS 20 kDa 93 2.7 3.6 7.1

91

Fig.1. Normalised pore volume distributions generated from DFT analysis of nitrogen porosimetry data.

CONCLUSIONS

From the combination of analysis methods employed in determining the pore size distributions of the adsorbents produced in this study it is evident that tailoring them to exclude albumin is possible. The use of toluene as the sole porogen produces a material with good characteristics for excluding albumin and would be significantly better than XAD-4 for example. The addition of naphthalene as a porogen improves the pore structure again by reducing the percentage of the pore volume accessible to molecules of an equivalent size to albumin by approximately 2% compared to an adsorbent generated with just toluene.

ACKNOWLEDGEMENTS

The authors would like to thank Dr A. Trochimczuk for his helpful discussions and advice during this project.

REFERENCES

1. J. F. Winchester, J. Salsberg, E. Yousha, Artificial Cells, Blood Substitutes, and Immobilization Biotechnology, 30(2002)547

2. C. Poinescu, C. Beldie, C. Vlad, J. Appl. Polym. Sci., 29(1984)23

0

0.01

0.02

0.03

0.04

0.05

0.06

10 100 1000

Pore Width (A)

Nor

mal

ised

Incr

emen

tal P

ore

Vol

ume

TolNap

TolUn

Tol

XAD-4

92

3. D. C. Sherrington, Chem. Commun., 21(1998)2275 4. R. F. T. Stepto, (ed) Polymer Networks Principles of Their Formation Structure

and Properties, London, Blackie Academic & Professional 1998 5. S. Durie, K. Jerabek, C. Mason, D. C. Sherrington, Macromolecules,

35(2002)9665 6. O. Okay, Prog. Polym. Sci., 25(2000)711 7. L. Hagel, J. Chromatogr. Lib. Vol. 40 Aqueous Size-exclusion Chromatography,

Edited by P. L. Dubin, Chapter 5 119 (1988)

93

ION EXCHANGE AND EXTRACTION CHROMATOGRAPHY AS A BAS IS OF SEPARATION SCHEMES FOR EFFICIENT SEPARATION AND

DETERMINATION OF SEVERAL ELEMENTS BY NAA AND OTHER TECHNIQUES

R. S. DYBCZYŃSKI, Z. SAMCZYŃSKI, E. CHAJDUK, B. DANKO, H.

POLKOWSKA-MOTRENKO

Department of Analytical Chemistry, Institute of Nuclear Chemistry and Technology, 03-195 Warszawa, Dorodna 16, Poland

Several separation schemes based on column ion exchange and extraction

chromatography, elaborated in the Department of Analytical Chemistry, Institute of Nuclear Chemistry and Technology, Warsaw are reviewed and their merits are discussed.

The unique possibilities of amphoteric resins are illustrated by the example of definitive method for the determination Cd in biological materials by neutron activation analysis (NAA, where the use of single column with Retardion 11 A8 enables selective and quantitative separation of Cd from practically all other elements with 100% yield and in a state of very high radiochemical purity as confirmed by γ-ray spectrometry [1-3].

Chelating resin Chelex 100 containing iminodiacetic acid functional groups also exhibits amphoteric properties. It has been used for preconcentration of Pd, Pt and Au from geological and industrial materials and their subsequent determination by NAA. [4]

Another newly devised separation scheme for an accurate determination of Se in biological materials by NAA is also presented. Selenium is quantitatively and selectively separated from all other radionuclides on a column with 3,3’-diaminobenzidine supported on Amberlite XAD 4 and measured directly in the stationary phase [5]. New pre-irradiation separation scheme for the selective and truly quantitative isolation of the lanthanides from biological materials was devised and used for the determination of individual lanthanides by NAA. The scheme includes also post-irradiation separation of REEs into two groups by anion exchange chromatography to minimize the spectral interferences [6] The above scheme was later also used for the determination of trace amount of lanthanides and yttrium by ion chromatography (IC).

Efficient and selective separation methods make possible accurate determination of trace amounts of many elements in various complex matrices as was demonstrated by the analysis of several certified reference materials (CRMs).

REFERENCES

1. Z. Samczyński, R. Dybczyński. Chem.Anal. (Warsaw), 41(1996)873 2. Z. Samczyński, R. Dybczyński. J. Chromatogr.A., 789(1997)157

94

3. R. S. Dybczyński, B. Danko, H. Polkowska-Motrenko, Z. Samczyński. Talanta, 71(2007)529

4. Z. Samczyński, B. Danko, R. Dybczyński. Chem. Anal. (Warsaw), 45(2000)843 5. H. Polkowska-Motrenko, E. Chajduk, R. Dybczyński. Chem. Anal. (Warsaw),

51(2006)581 6. B. Danko, Z. Samczyński, R. Dybczyński, Chem.Anal.(Warsaw), 51(2006)527

95

VALENCE CONTROL IN LANTHANIDE SEPARATION VIA SORPTI ON TECHNIQUES

Luděk JELÍNEK*, Yuezhou Wei** and Tsuyoshi Arai**

*Department of Power Engineering

ICT Prague, Technická 5, 166 28 Praha 6, Czech Republic e-mail: jelinekl@vscht.cz

**Institute of Research and Innovation 1201-Takada, Kashiwa, 277-0861 Chiba, Japan

In their main sources, minerals monazite and bastnasite, lanthanides are

present in a mixture. Similar chemical properties of lanthanides are making their mutual separation complicated. Lanthanides basically exist in aqueous solution in stable trivalent state. Fortunately, some lanthanides can be reduced or oxidized to other oxidation states. Such change can drastically change their chemical properties and thus enhance their separation.

Among Lanthanides only Ce can be oxidized to tetravalent state. Ce(III) oxidation in sulfuric acid media has been thoroughly investigated [1,2]. However, solubility of Ce(IV) in sulfuric acid is limited [3]. Unlike sulfates, nitrates can be easily removed by calcination. Nitric acid media allows working with high Ce(III) concentrations and brings the advantage of formation of Ce(IV) nitrato-complexes that can be subsequently separated by solvent extraction or ion exchange. Electro-oxidation of concentrated Ce solution (1 mol·dm-3) at carbon felt anode was described recently [4]. Solvent extraction way of Ce(IV) nitrato complexes has been studied in several papers mainly using TBP as an extractant. Extractability of Ce(IV) increased with HNO3 concentration in studied range (0.5-5 mol·dm-3). [Ce(NO3)4] is thought to be the main adsorbed Ce(IV) species [5,6]. Anion exchangers can be utilized to adsorb anionic nitrato complexes of Ce(IV). However, the number of papers published on Ce(IV) separation by anion exchange has so far been very limited.

On the other hand, Eu can be reduced to divalent state that is relatively stable in aqueous solution. In industrial separation chemical reduction by zinc followed by precipitation of EuSO4 is used but with respect to ion exchange separation the electro-reduction is more suitable. Hydrochloric acid (HCl) is a preferred medium for Eu(III) electro-reduction because of its reducibility and high solubility of EuCl2. Electro-reduction of Eu(III) on different materials was studied extensively [7-9]. The number of papers on Eu(II) separation by other processes than sulfate precipitation is so far very limited. Only electro-reductive stripping of Eu(III) from loaded extractants and its recovery as Eu(II) sulphate was investigated7). In this work several sorbents that are suitable for rare earths separation via valence control is suggested.

96

Cerium(IV) separation from trivalent rare earths La(III) and Y(III) in nitric acid media was tested in two sorbents, tri-n-butylphosphate (TBP) impregnated resin and polyvinyl pyridine (PVP) based anion exchanger. All sorbents utilized porous silica support covered with polymer. Particle size was about 50 µm. Preparation of PVP anion exchangers SiPyRN3 and SiPyRN4 having pyridine and N-methylpyridinium functional groups, respectively, was described previously [10]. TBP impregnated resin (TBP/SiO2-P) was prepared by means of impregnating a dichloromethane solution of into the SiO2-P

11) beads (polystyrene/DVB copolymer immobilized in porous SiO2) evaporation of dichloromethane and drying in vacuum drying oven. 1 mol·dm-3 Ce(IV) solution was prepared [4] prior the sorption experiments and diluted to 1 mmol·dm-3 before the sorption run. 8 cm3 of sorbents was packed into glass column of inner diameter 1 cm (bed height 10 cm).

Europium(II) was prepared in closed system under protective Ar atmosphere. It was necessary to work in closed system to prevent Eu(II) reoxidation. Strong acid cation exchanger on porous silica support and bis-(2-ethylhexyl) phosphoric acid (HDEHP) impregnated resin HDEHP/SiO2-P. The resin was prepared in similar way as TBP/SiO2-P. Feed solution contained 1 mmol·dm-3 of chlorides of respective rare earths (La, Ce, Sm, Eu, Gd, Er, Yb) in 0.01 mol·dm-3 of hydrochloric acid. 600 cm3 of feed solution was placed into container and reduce in flow type electrolyzer at 3D glassy carbon fiber cathode at -800 mV vs. Ag/AgCl. Sorption column packed was packed with 5 cm3 (about 2.5 g of resin) of HDEHP/SiO2-P in slurry state. It has inner diameter of 8 mm and bed height of 100 mm. Eu(II) concentration was measured by direct UV spectroscopy [12] developed during the preliminary experiments. Total metal concentrations were measured by ICP-OES. Specific flow rates were ranging from 6-15 BV·h-1.

It was possible to selectively adsorb Ce(IV) onto TBP/SiO2-P from nitric acid solution [13]. Ce(IV) sorption increased with increasing nitric acid concentration (0.5-6 mol·dm-3). Oxidation of sorbent by adsorbed Ce(IV) species resulting in Ce(III) release to the solution and decrease of sorption was observed. This effect could be suppressed by lowered temperature. Column separation of Ce(IV) from Y(III) and La(III) was achieved in 6 mol.dm-3 HNO3 at 288K. Ce(IV) breakthrough capacity was 0.48 mol·kg-1-TBP. Column regeneration with 0.1 mol·dm-3 nitric acid yielded Ce solution with purity higher than 99.99 wt.% with respect to La and Y impurities. However, TBP leakage during the sorption cycle was about 12%.

PVP anion exchangers showed good stability in oxidative Ce(IV) solution in nitric acid. Ce(IV) reduction was much slower than in the case of commercial strong base anion exchanger. Sorption increased with increasing nitric acid concentration. From the Ce(IV) speciation it was evident that [Ce(NO3)6]

2- is the main adsorbed specie. Column separation of Ce(IV) from Y(III) and La(III) was carried out from 6 mol·dm-3 nitric acid at lowered temperatures [14]. Reasonable Ce(IV) breakthrough capacity (0.7 mol·kg-1-PVP) was achieved. No remarkable decrease of capacity was observed within 3 consequent runs. Regeneration with 0.1 mol·dm-3 nitric acid was

97

successful (recovery 100±4 %) and gained Ce solution of high purity (>99.97%) with respect to La and Y content.

Eu(II) separation from trivalent lanthanides by strong acid cation exchanger in hydrochloric acid medium was partly successful. Eu(II) exhibited lower affinity towards the cation exchanger than trivalent lanthanides and therefore it was the first species to breakthrough the column. Excellent separation from middle rare earths was achieved while the separation from heavy rare earths was incomplete. The re-oxidation of Eu(II) during the sorption run was a problem despite all the measures that were taken to prevent oxidation by dissolved oxygen and photo-oxidation. Eu(II) showed much lower affinity towards the HDEHP/SiO2-P resin than the trivalent lanthanides and brokethrough the column readily. During the sorption run Eu of purity higher than 99.8% was yielded. The back-oxidation of Eu(II) was observed during the sorption and Eu(III) was absorbed onto the resin. Adsorbed light and middle rare earths could be stripped from loaded resin by 3 mol·dm-3 hydrochloric acid. Stripping of heavy lanthanides (Er, Yb) was problematic with recovery ratio <50%. Thus, ideal application of both sorbents will be final purification of Eu in middle lanthanide mixture Sm, Eu, Gd.

ACKNOWLEDGEMENT

This work was financially supported by Japan Society for Promotion of Science (JSPS)

REFERENCES

1. T. Randle, A. Kuhn, Electrochim. Acta, 31(1986)739 2. B. Fang, S. Iwasa, Y-Z. Wei, T. Arai, M. Kumagai. Electrochim. Acta,

447(2002)3971 3. Y-Z. Wei, B. Fang, M. Kumagai, J. Appl. Electrochem., 35(2005)561 4. L. Jelinek, Y-Z. Wei, M. Kumagai, J. Rare Earths, 24(2006)257 5. Y-C. Hoh, T-Y. Wei, Y-Y. Wang, T-M.Chiu, Hydrometallurgy, 19(1987)209 6. C. S. Kedari, S. S. Pandit, A. Ramanujam, J. Radioanal. Nucl. Chem.,

22(1997)141 7. N. Hirai, I. Komasawa, J. Chem. Eng. Japan, 25(1992)644 8. A. G. Atanasyans, A. N. Seryogin, Hydrometallurgy, 37(1995)367 9. T. Hirato, H. Kajiyama, H. Majima, Y. Awakura, Metall. Mater. Trans. B.,

26(1995)1175 10. K. Horiguchi, et al., J. Ion Exchange., 14(2003)68 11. Y-Z. Wei, et al., Nucl. Technol., 132(2000)413 12. L. Jelinek, T. Arai, Y-Z. Wei, M. Kumagai, J. Rare Earths., 25(2007)1 13. L. Jelinek, Y-Z. Wei, M. Kumagai, Solvent Extr. Ion Exch., 24(2006)765 14. L. Jelinek, Y-Z. Wei, M. Kumagai, J. Rare Earths., 24(2006)385

98

APPLICATION OF WEAKLY AND STRONGLY BASIC ANION EXCHANGERS FOR THE REMOVAL OF SULPHONATED AZO DYE

Monika LESZCZYŃSKA♦, Zbigniew HUBICKI

Department of Inorganic Chemistry, Faculty of Chemistry, Maria Curie-

Skłodowska Sq.2, Maria Curie-Skłodowska University, 20-031 Lublin, Poland

Azo dyes (including the sulphonated azo dyes) are a very important class of

synthetic colours characterized by the presence of one or more chromophoric azo groups (―N═N― ) in their structure [1-3]. Since the second half of the 19th century, they have been extensively used in numerous industrial branches. Currently, there are over 3000 azo dyes in use worldwide and they account for 65% of the commercial dye market [1].

Large quantities of sulphonated azo dyes are applied in many filds of up-to-date technologies, e.g. textile industry, paper production, leather tanning industry, food and cosmetics as well as in photoelectrochemical cells, photography and reprography, for pharmaceutical and medical diagnostic purposes and in agricultural research [4,5]. Moreover, synthetic dyes containing sulphonic groups have been employed as indicators for the determination of some metal ions because they are the most versatile chelating agents forming stable complexes with heavy metal ions [6-8].

A wide group of sulphonated azo dyes have also been immobilized on anion-exchange resins in order to transform them into chelating resins which can be used in sorption – spectroscopic test methods for sensitive determination of metal ions in the environmental analysis [9,10]. Due to large–scale production and extensive application, sulphonated azo dyes can cause considerable environmental pollution and are serious health-risk factors. Although, the stringent regulations for the quality of potable water have led to enhanced interest in the decontamination of wastewater. A wide range of methods has been developed for the removal of synthetic dyes from waters and wastewaters to decrease their impact on the environment. The technologies involve adsorption on organic or inorganic matrices, decolorization by photocatalysis, and/or by oxidation processes, microbiological or enzymatic decomposition, etc. [4,11]. Some examples are presented and summarized in Table 1 [11].

Table 1. Current treatment technologies for dyes removal [11]

♦ corresponding author: tel.+48 81 5375738; fax +48 81 5333348 e-mail: mleszczynska@vp.pl,

99

Chemical and/or physical methods

Advantages Disadvantages

Adsorption Effective removal of a wide range of dyes

Absorbent requires regeneration or disposal

Oxidation Rapid process High energy costs and formation of by-products

Membrane technologies Removal of all types of dyes

Concentrated sludge production

Coagulation/flocculation Economically feasible

High sludge production

The research presented here concerns the usefulness of the weakly and

strongly basic (type I) anion-exchange resins: Amberlite IRA-67, Amberlite IRA-402 and Amberlite IRA-958 (Table 2) in recovery of the sulphonated azo dye - brilliant yellow from aqueous solutions (Fig.1). The batch experiments were carried out in order to determine the recovery factors of brillant yellow (%R). The effect of initial concentration of brilliant yellow in the range from 1×10-4 to 1×10-2 M and phase contact time on the percentage uptake was investigated. The influence of temperature and pH on adsorption behaviour of the dye on the above mentioned anion-exchangers was studied. The adsorption isotherms of brilliant yellow on Amberlite IRA-67, Amberlite IRA-402 and Amberlite IRA-958 were determined, too. The breakthrough capacities of brilliant yellow for the applied anion – exchangers were calculated from the breakthrough curves.

The anion exchange resins modified by means of 2,2'(1,2-ethenediyl)bis[5-[(4-hydroxyphenyl)azo] benzenesulfonic acid]disodium salt (brilliant yellow) were also applied in order to remove Cu(II), Ni(II) or Co(II) ions from aqueous chloride solutions.

OH N N CH

SO3Na

CH N OHN

NaO3S

Fig.1. Brilliant yellow structure Table 2. Physicochemical properties of the anion – exchangers.

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Descriptions Amberlite IRA-67 Amberlite IRA-402 Amberlite IRA-958 Type Weakly basic Strongly basic Strongly basic Functional groups —N(R)2 —N+(CH3)3 —N+(CH3)3 Matrix Acrylic

divinylbenzene

Styrene divinylbenzene

Acrylic divinylbenzene

Structure Gel Gel Macroreticular Ionic form as shipped

Free base Cl- Cl-

Bead size [mm] 0.50 – 0.75 0.60 – 0.75 0.63 – 0.85 Total capacity [eq/dm3]

≥1.6 ≥1.3 ≥0.8

Max. operating temp. [oC]

6 60 60 80

Producer Rohm & Haas Rohm & Haas Rohm & Haas As follows from results the percentage uptake of brilliant yellow depends on the phase contact time as well as on the initial concentration of the azo dye for all used anion exchangers (Fig.2). pH and the temperature of the solution have insignificant influence on brilliant yellow recovery on the strongly and weakly basic anion exchangers.

0 60 120 180 240t [min.]

0

20

40

60

80

100

%R

Initial concentration:0.0005 M

0.001 M

0.002 M

0.004 M

0.006 M

0.008 M

0.01 M

Fig.2. Influence of initial concentration of brilliant yellow and phase contact time on the recovery factors of brilliant yellow for Amberlite IRA-958

It was found that affinity of this azo dye for the anion – exchangers of acrylic or styrene – divinylbenzene copolymer matrix can be presented in the following series (Fig.3):

101

Amberlite IRA-958 > Amberlite IRA-67 > Amberlite IRA-402.

Taking into consideration the values of brilliant yellow uptake by Amberlite IRA-958 and Amberlite IRA-67 it can be stated that they find practical application in removal of brilliant yellow from tannery wastes, pulp – mill liquors and as well as wastewaters originating from textile industry.

0 0.01 0.02 0.03Co [M]

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

Q [m

mo

l/g]

Amberlite IRA-402

Amberlite IRA-67

Amberlite IRA-958

Fig.3. Adsorption isotherms of brilliant yellow on the weakly (Amberlite IRA-67) and strongly (Amberlite IRA-402, Amberlite IRA-958) basic anion exchangers Brilliant yellow as aromatic complexing agent exhibit a high affinity not only for Amberlite IRA-67 but also for the strongly basic anion exchangers. Retained on the anion exchange resins it transforms them into chelating ion exchangers. The sorption mechanism of sulfo-derivative aromatic complexing agents (ACA(SO3)n

n-) on a strongly basic anion exchanger in the chloride form (RCl) can be described by means of the reaction:

n RCl + ACA(SO3)n

n-Rn(SO3)nACA + n Cl

_

As follows from the above, brilliant yellow (ACA(SO3)n

n-) forms a stable ion pair in the anion exchanger phase. It can be retained by means of a molecular mechanism (physical adsorption), too.

Modified anion exchangers by means of brilliant yellow can also be applied for Cu(II), Ni(II) and Co(II) ions recovery from wastewaters and their trace analysis.

102

REFERENCES

1. L. H. Ahlström, C. S. Eskilsson, E. Björklund, Trends Anal. Chem., 24(2005)49 2. A. Gnanamani, M. Bhaskar, R. Ganga, G. Sekaran, S. Sadulla, Chemosphere,

56(2004)833 3. F. Rafii, J. D. Hall, C. E. Cerniglia, Food Chem. Toxicol., 35(1997)897 4. E. Forgacs, T. Cserháti, G. Oros, Environmental International, 30(2004)953 5. J. Sokołowska, Barwniki w nowoczesnych technikach, Łódzkie Towarzystwo

Naukowe 2005 (in Polish) 6. D. K. Singh, M. Srivastava, Sep. Purif. Technol., 45(2005)1 7. R. Saxena, A. K. Singh, Anal. Chim. Acta, 340(1997)285 8. J. Chwastowska, E. Kosiarska, Talanta, 35(1988)439 9. K. Brajter, E. Dąbek-Złotorzyńska, Talanta, 27(1980)19 10. V. Vasić, J. Savić, V. Pavelkić, S. Milonjić, Coll. Surf. A, 215(2003)277 11. C. I. Pearce, J. R. Lloyd, J. T. Guthrie, Dyes and Pigments, 58(2003)179

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III. POSTERS

104

RECOVERY OF COLLAGEN HYDROLYSATE, Cr(III) AND OTHER METALS FROM LIQUID AND SOLID INDUSTRIAL WASTES

Zbigniew ADAMSKI1, Aleksandra KOTECKA1, Katarzyna ROTUSKA1, Wiesław APOSTOLUK1, Barbara WIONCZYK2, Witold CHAREWICZ1

1Division of Chemical Metallurgy, Department of Chemistry, WrocławUniversity of Technology, WybrzeŜe Wyspiańskiego 2, 50-370 Wroclaw, Poland

2Institute of Leather Industry, Zgierska 73, 91-462 Łódź, Poland Tanning industry generates large quantities of solid wastes which are dangerous pollutants. Storage of their in stationary stockyards is a serious problems. Having in mind the increasing environmental restrictions and escalating landfill costs numerous technologies of simultaneous removal of chromium(III) and collagen hydrolysates from tanned solid wastes have been developed. However, these methods are complicated, time consuming and usually consist of a great number of unit processes and operations [1-3]. In this work the treatment of chromium tanned solid wastes with NaOH solutions has been proposed [4]. This process has been studied in terms of variation of the following process variables:

• concentration of NaOH form 1.5 to 3 M, • time of leaching from 0.5 to 3h, • temperature from 353 to 373 K, • solid to liquid phase ratio from 1:10 to 1:3.

The optimal solid to liquid phase ratio has been established experimentally taking into account the total decomposition of tanned wastes, facility of mixing of reaction mixture, and the yield of chromium recovery. At low phase ratio the leach solution is viscous and gelatinous collagen hydrolysate is formed which makes separation of phases difficult due to the clogging of filter pores and increased time of filtration.

Under optimal conditions the solid tannery waste has been fully dissolved in sodium hydroxide solution while chromium has been completely precipitated as Cr(III) hydroxide. After the separation of phases the precipitate can be easily dissolved in sulphuric acid in order to prepare fresh tanning liquors. Aging of alkaline leach solution for 5 h at temperature 273-278 K is the best manner of separation of a greater part of collagen hydrolysate from mother solution. This fraction of collagen hydrolysate is practically free from chromium and can be directed to further utilization. Remaining solution, after correction of concentration of sodium hydroxide can be used in leaching of next portion of chromium tanned wastes. Recirculation of the leach solution is possible so long as the concentration of highly soluble fraction of collagen hydrolysate, which do not precipitate after cooling, is low. Therefore, a portion of such leach should be removed and replaced with equivalent volume of a fresh solution sodium hydroxide. From preliminary

105

experiments it follows that an alkaline leach solution containing highly soluble fraction of collagen hydrolysate could be used to neutralize acidic waste solutions from treatment of stainless steels and recover chromium, nickel, and cobalt.

ACKNOWLEDGEMENT

The Ministry of Science and High Education (Poland) is kindly acknowledged for the financial support through the grant T09B 045 26.

REFERENCES 1. W. Lasek, Recykling, 63(2006)26 2. L. F. Cabeza, M. M. Taylor, G. L. DiMaio, E. M. Brown, W. N. Marmer, R.

Arrio, P. J. Celma, J. Cot, Waste Management, 18(1998)211 3. C. Mu, W. Lin, M. Hang, Q. Zhu, Waste Management, 23(2003)835 4. A. Kotecka, Z. Adamski, B. Wionczyk, W. Apostoluk, W. Charewicz, Patent

Application P 381 767, 15.02.2007

106

RHENIUM RECOVERY FROM ACIDIC SOLUTION ON FUNCTIONALIZED RESINS

Dorota JERMAKOWICZ-BARTKOWIAK, BoŜena N. KOLARZ

Wroclaw University of Technology, Faculty of Chemistry, Department of Polymer and Carbonaceous Materials, WybrzeŜe Wyspiańskiego 27, 50-370 Wroclaw,

Poland; e-mail: dorota.jermakowicz-bartkowiak@pwr.wroc.pl

Rhenium is one of the most rarely occurring elements on the earth. Rhenium does not occur in nature as a free metal, but it can be found in certain copper or molybdenum ores. Rhenium is produced as a by-product of molybdenum production which is itself a by-product of copper production. Its abundance on the Earth's crust is relatively low, at 0.4 ppb, and even lower in seawater at 0.004 ppb (compared with molybdenum at 1.5 ppm and copper at 50 ppm) [1]. An enormous increase of rhenium prices together with the fact that world-wide supply of this metal is limited to 17000 tons only, have forced the search for new methods of its recovery [2].

Rhenium as an accompanying element is present in Polish copper concentrates. Its concentration reaches the level of 5 – 20 ppm [3,4]. Rhenium compounds evaporate during the thermal-processes of copper metallurgy and can be collected mainly in gas cleaning devices. Several technologies of rhenium recovery have been developed lately.

The new technology of rhenium recovery is selective sorption of perrhenate anions on functionalized resins during column processes. The elution of rhenium is carrying out with ammonia water giving ammonia perrhenate as final product [4].

This work has been focused on obtaining resins with ability to rhenium sorption and its separating from multicomponent acidic solutions. The matrix of suspension copolymers was modified with amines and resulted with ligands incorporated in copolymer structure. The properties of obtained ion-exchange and chelating resins were characterized by water regain, ion-exchange capacity and sorption of rhenium. Investigated resins showed 80-95% yield of rhenium sorption and revealed level of loading up to 50 mg of Rhenium for 1 gram of dry resin.

REFERENCES 1. L. V. Borisova, A. N. Ermakov, The Analytical Chemistry of Rhenium, Moscow,

1974 2. www.lipmann.co.uk 3. R. Chamer, K. Anyszkiewicz, G. Benke, K. Litwinionek, R. Kalinowski, Z. Śmieszek, A. Chmielarz, Rudy i Metale NieŜelazne, 9(2004)441

4. G. Benke, K. Anyszkiewicz, D. Hac, K. Litwinionek, K.Leszczyńska-Sejda Przemysł Chemiczny, 8-9(2006)793

This work was supported by the Polish Committee for Scientific Research under grant # N205 046 31/2046.

107

LABORATORY SIMULATION OF NICKEL(II), COBALT(II) AND CADMIUM(II) IONS SEPARATION IN A CONTINUOUS COUNTER –

CURRENT EXTRACTOR

Bernadeta GAJDA1), Mariusz B. BOGACKI2)

1) Częstochowa University of Technology, department of Metal Extraction and

Recirculation, Armii Krajowej 19, 420200 Częstochowa, Poland. 2) Poznań University of Technology, Institute of Chemical Technology and

Engineering. Pl. M. Skłodowskiej – Curie 2, 60,-965 Poznań, Poland, e-mail: Mariusz.Bogacki@put.poznan.pl

In this paper we present the study related to application of CYANEX 272 (di(2,4,4-trimethylpentyl)phosphinic acid) and D2EHPA (di(2-ethylhexyl)phosphoric acid) extractant in the extractive separation of nickel(II), cobalt(II) and cadmium(II) ions originating from a sulphate solution. Simulation of three-stage extraction process, performed in laboratory conditions, was conducted in vessel to multifold, consecutive mixing and phase separation. As the result of the extraction, the raffinates and extracts were obtained. The process was conducted until properties of the consecutively obtained extracts and raffinates products stabilized.

Laboratory simulation of the counter – current extraction process permitted to conclude that such a process allows for a selective separation of cobalt(II), nickel(II) and cadmium(II) ions from sulphate solutions. The obtained results indicate the need for pH control following every step of the extraction and for setting it at such a level which prevents against the parallel transfer of ions. The performed studies on the counter – current extraction process at a laboratory scale allow to draw significant technological conclusions related to the way in which the process should be conducted.

ACKNOWLEDGEMENT

The study was partially subsided by the grant No. 32-244/2007-DS provided by the Poznań University of Technology.

108

CONTRIBUTION OF SEPARATION METHODS TO NAA OF MOLYBDENUM AND LANTHANIDES IN THE MATERIALS

OF BIOLOGICAL ORIGIN

BoŜena DANKO, Rajmund DYBCZYŃSKI, Zbigniew SAMCZYŃSKI

Institute of Nuclear Chemistry and Technology,

Department of Analytical Chemistry, 03-195 Warszawa, ul Dorodna 16

Recently the growing interest in the analytical methods of high reliability has taken place. Radiochemical neutron activation analysis (RNAA) with the selective isolation of determined radionuclide as well as the NAA with pre-irradiation separation of the determined elements play an important role among other methods of inorganic trace analysis.

The separation procedures [1,2] - on the basis of ion-exchange and extraction column chromatography – have been used to obtain the isolated fraction of analytes, free from matrix and other trace constituents.

A number of studies employing radiotracers have been carried out in order to devise the final separation schemes for the analytical purposes. Some examples are presented in this paper.

The isolation of the analytes makes possible to overcome the numerous interferences, usually difficult to recognize, minimizing the uncertainty of the method. This in turn results in reliable quantification of the elements of interest. Neutron activation analysis is one of the few analytical methods capable of determination of low levels molybdenum and the lanthanides in a variety of matrices including biological materials.

The usefulness of the above methods for checking reliability of the routinely used analytical methods as well as for the certification of new reference materials is hard to overestimate, as illustrated by several practical examples.

REFERENCES

1. B. Danko, R. Dybczyński, J. Radioanal. Nucl. Chem., 216(1997)51 2. B. Danko, Z. Samczyński, R. Dybczyński, Chem. Anal. (Warsaw), 51(2006)527

109

FAST RESPONSIVE MACROPOROUS HYDROGELS

M. Valentina DINUa, M. Murat OZMENb, E. Stela DRAGANa, Oguz OKAYb,

a "Petru Poni" Institute of Macromolecular Chemistry, Functional Polymers Department, Iasi, Romania

b Istanbul Technical University, Department of Chemistry, Maslak 34469, Istanbul, Turkey

Responsive hydrogels are soft and smart materials, capable of changing

volume in response to specific external stimuli, such as the temperature, solvent quality, pH, electric field, etc [1]. These properties of the hydrogels received considerable interest and, a large number of hydrogel based devices have been proposed, including artificial organs, actuators, and on-off switches. However, the application of hydrogels is limited due to their slow rate of response as well as due to their lack of mechanical strength. In order to increase the response rate of hydrogels, several techniques were proposed, such as reducing the size of the gel particles [2], creating dangling chains on the gel samples [3], or, constructing an interconnected pore structure within the hydrogel matrices [4].

In order to obtain fast responsive macroporous hydrogels, the polymerization reactions were carried out below the freezing point of the solvent. In this technique, during freezing of the monomer solution, the monomers expelled from the ice concentrate within the channels between the ice crystals, so that the reactions only take place in these unfrozen liquid channels. After polymerization and, after melting of ice, a porous material is produced whose microstructure is a negative replica of the ice formed [5]. Recently, we have shown that by conducting the copolymerization-crosslinking reactions below –8°C, hydrogels based on 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS) monomers with superfast swelling properties could be obtained [6-8]. N,N’-methylenebis(acrylamide) (BAAm) was the crosslinker used in the hydrogel preparation.

In this study, polyacrylamide (PAAm) hydrogels were prepared by free-radical crosslinking copolymerization of AAm with BAAm in aqueous solution at various temperatures (Tprep) between -25°C and +25°C. The initial concentration of the monomer (AAm +BAAm), Co, as well as the crosslinker ratio X, which is the mole ratio of the crosslinker BAAm to the monomer AAm were also varied in the experiments.

It was shown that by conducting the polymerization reactions below -6°C, superfast swelling macroporous hydrogels can be obtained. PAAm networks with largest pores were obtained at –18°C. The pore sizes of the networks increased while the thickness of the pore walls decreased by decreasing the monomer concentration. The advantage of these macroporous hydrogels, so-called “cryogels” compared to

110

the macroporous hydrogels obtained by phase separation is their high mechanical stability. They are very tough, and can withstand high levels of deformations, such as elongation and torsion; they can also be squeezed under mechanical force to drain out their solvent content [9].

REFERENCES

1. M. Shibayama, T. Tanaka, Adv. Polym. Sci., 109(1993)1 2. K. S. Oh, J. S. Oh, H. S. Choi, Y. C. Bae, Macromolecules, 31(1998)7328 3. Y. Kaneko, K. Sakai, A. Kikuchi, R. Yoshida, Y. Sakurai, T. Okano,

Macromolecules, 28(1995)7717 4. O. Okay, Prog. Polym. Sci., 25(2000)711 5. V. I. Lozinsky, Russ. Chem. Rev., 71(2002)489 6. M. M. Ozmen, O. Okay, Polymer, 46(2005)8119 7. M. M. Ozmen, O. Okay, J. Macromol. Sci. Part A, 43(2006)1215 8. D. Ceylan, M. M. Ozmen, O. Okay, J. Appl. Polym. Sci., 99(2006)319 9. M. V. Dinu, M. M. Ozmen, E. S. Dragan, O. Okay, Polymer, 48(2007)195

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LINEAR AND CROSSLINKED WEAK POLYELECTROLYTES CONTAINING PRIMARY AMINE GROUPS

Ecaterina Stela DRAGAN, Maria Valentina DINU, Cristina Doina VLAD

“Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41

A, RO-700487 Iasi, Romania; e.mail: sdragan@icmpp.ro

Among the functional polymers, the linear and crosslinked copolymers bearing primary amine groups are of a great interest due to their high reactivity, which allows the incorporation of numerous additional moieties [1-4]. Some less explored ways to get linear or crosslinked copolymers containing primary amine groups have been employed in this study. Linear polymers containing p-aminomethylstyrene were obtained either by the Délepine reaction on the poly(chloromethylstyrene) (PCMS), i.e., the reaction of PCMS with hexamethylene tetramine, or by the formation first of a guanidinium salt between PCMS and guanidine followed by the alcaline hydrolysis to primary amine group [5].

Hofmann degradation of the amide groups has been also less explored when acrylamide was contained in a crosslinked copolymer [6-8]. For this purpose, some acrylamide copolymers crosslinked with either divinylbenzene or N,N’-methylene-bis(acrylamide) have been synthesized as beads by the suspension polymerization technique in water. Crosslinked weak polyelectrolytes have been also prepared by the aminolysis-hydrolysis reaction with 1,2-diaminoethane of the nitrile groups contained in some porous acrylonitrile-DVB copolymers. Due to the wide applicability of the selective chelating ion exchangers in the removal of toxic ions from industrial effluents, anion exchangers with primary amine groups were further post-derivatized by the carboxymethylation with ClCH2COONa to prepare porous chelating ion exchangers with iminodiacetic groups. FT-IR spectroscopy, solvent uptakes, morphological characterization in the dry state, and ion exchange capacity, all were used in order to obtain deeper information on the structural changes which take place by the chemical reactions on these copolymers.

REFERENCES 1. H. Tanaka, R. Senju, Bull. Chem. Soc. Jpn., 49(1976)2821 2. Y. Yamamoto, M. V. Sefton, J. Appl. Polym. Sci.,61(1996)351 3. D. J. Dawson, R. D. Gless, R. E. Wingard Jr, J. Am. Chem. Soc., 98(1976)5996 4. P. V. Prabhakaran, S. Venkatachalan, K. N. Ninan, Eur. Polym. J., 35(1999)1743 5. E. S. Dragan, (manuscript in preparation) 6. E. S. Dragan, C. D. Vlad, Macromol. Symp.,181(2002)47 7. E. S. Dragan, C. D. Vlad, M. V. Dinu, J. Appl. Polym. Sci., 89(2003)2701 8. E. S. Dragan, E. Avram, M. V. Dinu, Polym. Adv. Technol., 17(2006)571

112

PLASMA MODIFICATION OF POLYMER MEMBRANES

Irena GANCARZ, Gryzelda POŹNIAK, Jolanta BRYJAK, Marek BRYJAK, Jerzy KUNICKI*

Department of Chemistry, Wrocław University of Technology, WybrzeŜe

Wyspiańskiego 27 50-370 Wrocław * Central Laboratory of Batteries and Cells, ul. Forteczna 12, 61-362 Poznań

INTRODUCTION

Nowadays, membrane processes are receiving considerable interest in many fields of industry. The number of polymers appropriate for membrane preparations is limited so to fulfill diverse process requirements, modification of known and commonly used membranes is often applied.

Plasma is an excellent technique for that for a few reasons. Plasma can activate only the upper layer of the membrane not affecting the bulk properties of the polymer. Additionally, this technique is:

• versatile – when changing plasma gas and process parameters one can obtain the whole bunch of membranes of various properties, from just one membrane

• very effective – process usually lasts only a few minutes, • environmentally friendly – process produces neither by-products nor

wastes. The present paper is a review of our numerous works realized in this field

which aim was to improve ultrafiltration membranes properties, to get new nanofiltration and ion-exchange membranes, to introduce the surface functional groups as the anchor sites for covalent immobilization of biomolecules and to find the other application for modified membranes. Two different plasma apparatus (one operating at a frequency 2.45 GHz and other at 75 kHz) were used to modify porous and solid hydrophobic polymer membranes including polyethylene (PE), polypropylene (PP), polysulfone (PSU), poly(phenylene oxide) (PPO), polyacrylonitrile (PAN) and poly(etherimide) (PEI). Various plasma processes were applied - treatment with plasma of non-polymerizing gases (air, Ar, CO2, N2, NH3, NH3+Ar), plasma polymerization (acrylic acid, allyl alcohol, allylamine, n-butylamine) and plasma-initiated surface grafting (acrylic acid, 4-styrenesulfonic acid).

The data of FTIR-ATR, XPS and chemical analysis, used to confirm the chemical structure of the modified surface are given in the corresponding papers cited in the text.

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EXPERIMENTAL

Membranes of poly (phenylene oxide) (PPO, Mv=27 kDa, Aldrich) and polysulfone (PSU, Udel P-1700, Mv=33 kDa, Amoco) were prepared in laboratory. Dense membranes were cast from DMF or CHCl3 solution and dried in 120°C. Porous membranes were prepared by the phase inversion method from 15% solution in DMF with 10% of PVP (Mw=10 kDa) for PSU and a mixture of chloroform and nonyl alcohol (8:2 by weight) for PPO. Coagulation medium was water and methanol, respectively.

Porous membranes of poly(etherimide) and poly(acrylonitrile) were gift from Sulzer Chemtech GmbH and polypropylene (Celgard 2500) was the product of Daicel Chemical Industries, Ltd.

Two various plasma apparatus were used – a microwave plasma generator of 2.45 GHz frequency (Plazmatronika, Poland) and 75 kHz plasma generator (Dora, Wroclaw). In the former one, plasma was generated in a quartz tube at the top of the glass reaction chamber. Membranes were attached to a table in the post discharge area at various distances from the lower edge of the plasma. In the latter one sample was attached to the one of the electrodes. The details of parameters of all processes are given in the corresponding papers cited in the text.

In plasma induced grafting, the polymer sample after argon plasma treatment was left in air for 10 min, then soaked in a deaerated monomer solution and kept in a constant temperature bath (PSU, PPO) or exposed to wide-range UV irradiation (PP) for predetermined time. PSU and PPO porous membranes were hydrophilized in 1:1 ethyl alcohol-water solution prior to the grafting. After graft polymerization the membranes were extracted in distilled water in order to remove the homopolymer.

Contact angles were detected by means of TM 50 System (Technicome SA, France). Data of contact angles of water and diiodomethane were used for calculation of surface tension γ s and its polar γ s

p and dispersive γ sd components

according to [1]. Sample polarity was defined as ratio of γ sp /γ s.

The Amicon 8200 dead-end cell with a membrane surface area of 19.6 cm2 was used in filtration study. The performance of ultrafiltration (UF) membranes was determined with water, buffers and buffered solutions of bovine serum albumin (BSA, 1g/dcm

3). Values of fouling index (FI), flux recovery after cleaning (FR) and

reduction of the flow in filtration (RF) were calculated as follows: FI=[1–(J f /Jo)]; FR=Jc /Jo; RF=[1 – (Jp /Jo)]; where: Jo is flow of buffer through the fresh membrane, Jp - flow of buffered BSA through the same membrane, Jf – flow of buffer through the membrane after BSA filtration, and Jc – flow of buffer after membrane cleaning. In micellar enhanced UF (MEUF), a mixture of 2,4-D-herbicide and the surfactant, hexadecyltrimethylammonium bromide (CTAB), was filtered. The concentration of CTAB (conductivity) and 2,4-D-herbicide (UV absorption, 283 nm) in the permeate was determined. In nanofiltration studies, water solutions of salts (1 mmol/dm3) were filtrated.

114

Concentration of salt in permeate was determined (conductivity or atomic absorption). Salt rejection was calculated as: R (%) = (1 – Cp/Co) x 100, where Cp and Co are salt conc. in permeate and in the initial solution, respectively. Immobilization of chosen enzymes (xylose isomerase and invertase) was conducted on the modified by plasma dense membranes. Activation of functional groups prior to immobilization was done with divinylsulfone (hydroxyl) or glutaraldehyde (amino groups). Concentration of protein and sugars was estimated from UV absorption data. Determination of the electrolytic resistance R (om x cm2) of the membrane was determined by measurement of the potential between two reference electrodes at a fixed current that flowed between platinum electrodes. In all measurements concentrated KOH solution (d=1.28 g/cm3) was used.

RESULTS AND DISCUSSION

Plasma of non-polymerizable gases

Most polymers to be used for preparation of filtration membranes have strongly hydrophobic character. That is one of the reasons why such membranes fouls to the high extend. Plasma hydrophilization seems to be an attractive approach to reduce protein fouling and to improve the cleaning process of the membranes. Plasma treatment almost always causes increase of surface tension and polarity of polymer samples. PAN surface becomes almost twice as polar after air plasma treatment (increase of polarity from 44 to 85%) [2] and PE even 10 times more polar (increase from 6 to 60%) [3] than unmodified polymers. In the same time plasma etching causes increase of membrane pore size. These two phenomena affect the permeate fluxes through membranes. The flux change is sometimes very significant, for example for PEI membrane treated in argon plasma water flux increases 4 to 9 times depending on plasma parameters [4]. The serious drawback of plasma modification is diminishing of gained hydrophilicity with time.

The most detailed study of plasma influence on filtration performance was performed on PSU membranes. Plasma of non-polymerizable gases as CO2 [5], N2 [6] and NH3 [7] was applied. In all cases a sharp decrease in water contact angle hence increase of polar component of surface tension, in the first minute of plasma treatment was observed. Prolonged excitation did not cause further changes in surface tension and SEM pictures had shown intensive etching [5].

Filtration process of protein (BSA) using native and modified membranes was characterized by fouling index (FI), reduction of the flux in filtration (RF) and flux recovery after cleaning (FR). It can be seen in Table 1 that CO2, N2 and NH3 plasma modified membranes show better performance than untreated ones. In some cases this performance depends also on pH of protein solution. CO2 plasma modified PSU works better in basic solution (both BSA and membrane are negatively charged so repulsion takes place), N2 plasma gives surface of amphotheric character – filtration in whole pH range seems to be similar. NH3 plasma unexpectedly seems to leave slightly acidic surface. In case of PSU, the best performance in BSA filtration

115

show the CO2 plasma modified membranes. Air and argon plasma treated membranes show better filtration performance in acidic solution. In almost all cases of plasma treatment significant improvement of flux recovery after cleaning was noted. It means that plasma hydrophilization helps in protein removal from the fouled surface.

Table 1. Surface properties and ultrafiltration performance of chosen membranes

Surface properties Characteristic filtration parameters

PH=3 pH=9

Base

polymer

Plasma

medium Surface

tension,

mN/m

Polarity

% FI FR RF FI FR RF

None 45.9 2.0 59.9 53,2 82.5 53.5 68.4 72.9

CO2 61.8 51.8 50.9 88.2 67.5 22.1 100.0 35.1

N2 59.2 49.0 47.5 87.0 62.5 45.5 89.5 59.8

NH3 55.3 47.0 58.0 69.8 73.2 45.3 72.8 71.1

n-BuNH2 37.2 18.0 69.8 36.21 69.1 53.5 48.7 53.3

n-BuNH2

+Ar

44.6 22.9 23,7 92.1 54.7 62.9 48.9 78.9

AllNH 2 44.9 24.3 42.5 77.6 61.7 43.2 86.0 58.3

AllNH 2 +

Ar

76.5 52.3 28.4 90.3 28.8 19.0 100.0 20.0

PSU

AAc 67.6 63.0 65.7 45.1 82.2 41.6 76.5 64.3

Plasma polymerization

Using vapors of organic compounds as plasma medium makes possible a deposition of layer of a new material on the membrane surface. In this process, the starting monomer is highly degraded, the resulting fragments are scrambled, hence the chemical structure of the deposited film is significantly different from the structure of the monomer. However, in the mild plasma conditions (pulsed, remote plasma, low power) high retention of monomer structure is observed. In that way PSU or PPO membranes bearing amine [8-11], hydroxyl [12] or carboxyl [13] groups were obtained by plasma polymerization of n-butyl amine (n-BuNH2) [8,9] and allylamine (AllNH2) [9-11], allyl alcohol (AllOH) [12] and acrylic acid (AAc) [13] respectively. Presence of these groups on the surface can improve filtration performance of membranes and also may play the role of “anchoring sites” for biomolecules. The final result of plasma polymerization depends strongly on the composition of plasma medium. The presence of neutral gas (argon) stabilizes the plasma but sometimes gives unexpected results. Improvement of UF membranes performance

Plasma polymerization of all monomers causes decrease of water permeability through PSU membrane thus only short polymerization time can be

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applied for UF membranes. Performance of membranes in protein solutions at various pH gives us information on their surface character. Good filtration properties (Tab.1) are observed for AAc modified PSU in basic solution (acidic surface) [13] and in the whole range of pH in case of All-NH2 (with and without Ar) plasma treated PSU (amphotheric surface) [9]. N-butyl amine plasma makes the surface more hydrophobic and modified membranes with worsened filtration properties [8,9]. Addition of argon to n-butyl amine vapor improves membrane performance only in acidic solution (basic surface) (Tab. 1).

Membranes for micellar enhanced UF Sulfonated porous PPO membranes covered with allylamine plasma

polymer retained their ultrafiltration structure. We examined the possibility of their application in the process of micellar enhanced ultrafiltration. It is a technology that employs surfactant micelles to increase the ability of UF membranes in separation of small molecules [14]. Beyond the critical micelle concentration, the surfactant forms large aggregates (micelles of size above 10 nm) in which the organic or inorganic contaminants are solubilized. After that they can be separated by means of suitable UF membrane. This technology seems to be very promising in removal of herbicides from drinking water. The results obtained in the process of removing 2,4-D herbicide from water using modified PPO membrane are shown in Table 2. The performance of modified membrane is better than native one – the former rejected much more herbicide than PPO did. The probable reason for such behavior is repulsion of positively charged groups of surfactant and amine groups on the polymer surface.

Table 2. MEUF properties of PPO membranes

2,4-D herbicide rejection,%

Cs/Ch*

Membrane

Water flux

dm3 /m2 h 0.92 1.84

PPO 56.5 72 78

SPPO-ppAllNH2 68.2 55 92

*Cs/Ch – molar conc. ratio of CTAB to herbicide

Bipolar composite nanofiltration membranes

In this study sulfonated PSU (bearing negative charge) of sulfonation degree equal to 0.25 was applied as a support layer. The upper layer of bipolar membrane was prepared using plasma polymerization process of n-butylamine or allylamine, what gave the skin of weakly basic character. Such membranes were examined with solutions of single electrolytes containing cations and anions of various valences as well as the mixture of salts [15]. They showed higher rejection of magnesium sulfate

117

than sodium chloride. Differences of rejection of sodium chloride and magnesium chloride as well as Na2SO4 and MgSO4 are smaller than for monopolar membranes (Table 3). No essential difference between MgSO4 rejection from single salt solution and mixture was observed. As in the case of monopolar membranes, NaCl rejection was much lower in the mixture of salts solution. Bipolar membranes with allylamine plasma polymer show better separation properties than these with n-butylamine layer. Such bipolar membranes should be effective in water softening process as they show high salt solution fluxes and high rejection of divalent ions.

Table 3. Properties of nanofiltration membranes

Single salts retention, % NaCl+MgSO4 Kind of membrane Jw

dm3/m2h NaCl MgCl2 Na2SO

4 MgSO

4 MgSO

4 NaCl

monopolar* 5.8 60 14 96 44 44 21

BuNH2 4.9 35 21 71 56 57 19 bipolar

AllNH 2 4.6 26 25 70 69 68 19

*the best from investigated monopolar nanofiltration membranes – PSU+PVP/SPSU [12]

Enzyme immobilization

PSU and PPO membranes with plasma polymers of various compounds (allyl alcohol, n-butylamine, allylamine) deposited on their surfaces were used for covalent immobilization of two technologically important enzymes – xylose isomerase [10,12] and invertase [11]. Presence of argon in plasma medium stabilized the plasma but deposited layer seemed to have less functional groups. The enzyme activity was usually higher (n-butyl amine plasma is an exception) in that case. The enzyme activity varied strongly with plasma parameters as pulses, power, treatment time or sample-to-plasma distance. The last parameter seemed to have the strongest influence on enzyme immobilization. The values of enzyme activity obtained for modified PSU were in the range of 10.3 to 35.2 µmol/min and for plasma treated PPO – from 10.8 to 44.9 µg/min. There is no simple correlation between the polarity of modified samples or concentration of active groups on the surface and enzyme activity [11].

Plasma-induced surface grafting

Exposure of the polymer to inert gas plasmas (Ar, He, Ne) results mainly in free radical formation on the surface. These radicals can directly initiate polymerization of monomers (vapor phase grafting). In contact with air they can produce on the surface peroxides and hydroperoxides, which can be a source of succesive radicals in solution grafting.

118

PSU and PPO membranes PSU membranes were grafted with acrylic acid both in vapor (VG-PSU) and

solution (SG-PSU) [10] to get weakly acidic surface. Depending on plasma and grafting parameters grafting yield reached values from 26 to 261 µg/cm2 for VG-PSU and 0.3 to 12.4 µg/cm2 for SG-PSU. Permeability of water for VG-PSU dramatically decreases when degree of grafting approaches 50 g/cm2. Below that value filtration of protein is significantly improved in basic medium (Tab. 4). For SG-PSU one observes constant decrease of water flux with grafting yield and its value was too small to study protein filtration.

Table 4. Properties of grafted polymer membranes

Grafting Surface properties Characteristic filtration parameters

pH=3 pH=9

Base

polymer monomer yield,

µg/cm2

γs

mN/m

polarity

% FI FR RF FI FR RF

None 0 45.9 2.0 59.9 53.2 82.5 53.5 68.4 72.9

AAc* 34.0 56.5 56.0 66.1 42.2 77.2 40.7 80.0 53.6

PSU

NaSS 30.3 49.8 31.5 63.0 61.7 97.0 38.4 87.3 41.6

None 0 42.8 5.1 37.0 113.0 50.0 33.0 113.0 42.0 PPO

NaSS - 47.8 22.2 50.0 78.0 48.0 38.0 98.0 41.0

Electrolytic area resistance, om x cm2

None 0 29.3 2.0 130 000

AAc* - - - 9402 – 105 270

PP

AAc 100-

1000**

60.4 39.0 18 – 89**

* grafting in vapor phase ** - depending on plasma and grafting parameters

Strongly acidic surface could be obtained by surface grafting of sodium salt of sulfonic acid (NaSS). Degree of grafting for PSU depending on plasma and grafting parameters reached values from 4 to 42.3 µg/cm2. As in the case of acrylic acid, NaSS grafted PSU membranes show excellent transport properties in solution of pH above 7 (Tab. 4) [4]. In acidic solutions however filtration parameters are even worse then for unmodified PSU membrane. In case of PPO, grafting with NaSS worsen filtration performance of the membranes [14].

The grafted polymer does not form a uniform layer on the surface but it appears as agglomerates of various sizes, scattered on the substrate [14].

PP porous membranes Microporous polypropylene is an excellent membrane from point of view of

chemicals and temperature resistance. It is however very hydrophobic with surface tension of 29.3 mN/m and polar component only 0.6 mN/m. Durable, not changing with time wettability is the main condition of its wider application. Plasma-induced

119

grafting of acrylic acid seemed to be the proper method to reach this aim. The grafting was conducted both in vapor phase and solution but the first method appeared to be not very effective. Grafting in solution allowed introducing to polypropylene up to 1 mg of acrylic acid per 1 cm2 of the membrane (Table 4) in form of even polymer layer on the membrane surface (Fig.1).

a b

Fig.1. SEM of surface of PP virgin (a) and AAc grafted membrane (b) Such membranes became hydrophilic (polarity around 20%) and were characterized by very high ionic conductivity (Table 5) what makes it a good candidate for a separator in rechargeable high-power Ni/Cd cells [16].

CONCLUSION

Modification of membranes in plasma is a possible in simple and fast way to

improve their performances and to widen their application.

REFERENCES

1. S. Wu, Polymer Interface and Adhesion, M. Dekker, New York 1982 2. M. Bryjak, I. Gancarz, A. Krajciewicz, J. Pigłowski, Angew. Makromol. Chem.,

234(1996)21 3. M. Bryjak, I. Garncarz, Angew. Makromol. Chem., 219(1994)117 4. I. Gancarz, unpublished data 5. I. Gancarz, G. Poźniak, M. Bryjak, Eur. Polym. J., 35(1999)1419 6. I. Gancarz, G. Poźniak, M. Bryjak, Eur. Polym. J., 36(2000)1563 7. M. Bryjak, I. Gancarz, G. Poźniak, W. Tylus, Eur. Polym. J., 38(2002)717 8. G. Poźniak, I. Gancarz, M. Bryjak, W. Tylus, Desalination, 146(2002)293 9. I. Gancarz, G. Poźniak, M. Bryjak, W. Tylus, Eur. Polym. J., 38(2002)1937 10. I. Gancarz, J. Bryjak, G. Poźniak, W. Tylus, Eur Polym. J., 39(2003)2217 11. I. Gancarz, J. Bryjak, G. Poźniak G., W. Tylus, Eur. Polym. J., 42(2006)2430

120

12. I. Gancarz, J. Bryjak, M. Bryjak, G. Poźniak, W. Tylus, Eur. Polym. J., 39(2003)1615

13. I. Gancarz, G. Poźniak, M.Bryjak, A. Frankiewicz, Acta Polym., 50(1999)317 14. G. Poźniak, I. Gancarz, W. Tylu, Desalination, 198(2006)215 15. G. Poźniak, I. Gancarz, M.Bryjak, Proceedings of the 27th International

Conference SSCHE, Tatranske Matlare, Slovak Republik, 2001, 108 16. A. Ciszewski, I. Gancarz, J. Kunicki, M. Bryjak, Surf. Coat. Technol.,

201(2006)3676

121

ADSORPTION OF LANTHANIDES ON Na-MORDENITE

Agnieszka GŁADYSZ-PŁASKA, Marek MAJDAN

Faculty of Chemistry UMCS, 20-031 Lublin, Maria Curie-Skłodowska square 2, Poland

The adsorption of the lanthanides (except for Pm) on the mordenite was

investigated under various solution conditions of nitrate ion concentrations ( [NO3-] :

0.001-2 mol/dm3) and total lanthanide concentrations 0.0005 mol/dm3. Zeolite CBV 10 A (mordenite) in the form of powder has been delivered by Zeolyst International. Chemical composition of the samples has been reported by the supplier as: Na2O – w/w 6.6%, SiO2 /Al2O3 = 13.

EXPERIMENTAL

The aqueous phases (100 cm3 volume) containing lanthanide nitrates (0.0005 mol/dm3; 99.9% purity, Sigma Aldrich) dissolved in sodium nitrate with concentrations ranging from 0.001mol/dm3 to 2 mol/dm3 (pure, Sigma Aldrich) were equilibrated through 4h with 100 mg samples of the sodium form of the mordenite in temperature 23±10C. The aqueous phase was separated from the solid residue by filtration (paper filter Filtrak 390, Polskie Odczynniki Chemiczne) and the concentration of the lanthanides was determined spectrophotometrically using Arsenazo III [1]. The concentration of the lanthanide in the solid phase cZe was found as the difference between the initial concentration cin and the concentration in the equilibrium aqueous phase caq. The initial and equilibrium pH values were controlled using combined glass electrode (Sigma Chemical Co.) connected to the pH meter (CX-731 type, Elmetron Co.).

RESULTS AND DISCUSSION

The change of the distribution constants of the lanthanides in the system

Ln(NO3)3-NaNO3-mordenite with the nitrates concentrations is given in Figure. The distribution constants Kd are defined as:

Kd = (cZe/ caq)V/m. (1) where: V and m denote the volume of aqueous phase and the mass of the adsorbent respectively.

The nonmonotous change of log Kd values with the atomic number of the tripositive lanthanides is evident. For the first tetrad of the lanthanides (La-Nd) the concave deviation from the interpolation straightline in the run of Kd values is observed. Second tetrad (Pm-Gd) was not considered since we do not have the data for Pm. For the third tetrad (Gd-Ho) the negative deviation from the interpolation

122

line is noticed. For the fourth tetrad (Er-Lu), similarly as in the case of the first tetrad, concave deviations are evident especially for higher concentrations of nitrates (0.2 – 2 mol/dm3). According to Kawabe [2-6], the concave tetrad is observed when the covalency in lanthanide ion-ligand in products of the complexation reaction is Fig.1. The changes of distribution constants (Kd) of the lanthanides in the system NaNO3 – mordenite with nitrate concentrations.

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

log

Kd

-2

-1

0,2 [mol/dm3] NaNO3

0,5 [mol/dm3] NaNO3

0,8 [mol/dm3] NaNO3

1,0 [mol/dm3] NaNO3

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

log

Kd

-4

-3

-2

-1

0

1,2 [mol/dm3] NaNO3

1,4 [mol/dm3] NaNO3

1,6 [mol/dm3] NaNO3

1,8 [mol/dm3] NaNO3

2,0 [mol/dm3] NaNO3

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

log

Kd

-1

0

1

2

0,001[mol/dm3] NaNO3

0,01 [mol/dm3] NaNO3

0,1 [mol/dm3] NaNO3

123

weaker, i.e. Racah parameters are higher, than in the substrates. Therefore for the ions: La3+-Nd3+, when the ion exchange-complexation reaction of the aquoions Ln(H2O)9

3+ with the sodium form NaZe of the zeolite is considered: Ln(H2O)9

3+ + 3NaZe↔Ln(H2O)x Ze3 + 3 Na+ +(9-x) H2O (2) covalency of the Ln-O bond in the Ln(H2O)x Ze3 species is weaker than in aquocomplex Ln(H2O)9

3+. Apart from above mentioned reactions the complexation of the lanthanide ions by nitrates should be taken into account, according to general reaction:

Ln(H2O)n3+ + NO3

- ↔Ln(H2O)xNO32+ + (n-x) H2O (3)

where n=9 and 8 for the light and heavy lanthanides [7].

REFERENCES

1. Z. Marczenko, M. Balcerzak. "Spektrofotometryczne metody w analizie nieorganicznej", Wydawnictwo PWN SA, Warszawa 1998, p.353

2. A. Ohta, I. Kawabe, Geochem. J., 34(2000)455 3. A. Ohta, I. Kawabe, Geochem. J., 34(2000)439 4. I. Kawabe, A. Ohta, N. Miura, Geochem. J., 33(1999)181 5. A. Ohta, S. Ishii, M. Sakakibara, A. Mizuno, I. Kawabe, Geochem. J.,

33(1999)339 6. I. Kawabe, T. Toriumi, A. Ohta, N. Miura, Geochem. J., 32(1998)213 7. M. Majdan, A. Gładysz-Płaska, S. Pikus, D. Sternik, O. Maryuk, E. Zięba, P.

Sadowski, J. Mol. Struct. 702(2004)95

124

PROPERTIES OF Cu(II) IONS COORDINATED BY MOLECULAR IMPRINTED POLYMERS WITH AMINOGUANIDYL LIGANDS INSID E

THE IMPRINTS

Anna JAKUBIAK, BoŜena N. KOLARZ

Faculty of Chemistry, Wrocław University of Technology, WybrzeŜe Wyspiańskiego 27, 50-370 Wrocław, Poland

In recent years one of the most promising approaches to design materials able to selective and specific recognition of target molecules is molecular imprinting technique (MIT) [1]. This technique consists in preorganization of functional monomers around the template/template analogue molecule and subsequent crosslinking polymerization of formed assembly. Removal of the template leads to the remaining of the specific recognition cavities in the polymer matrix, spatially and functionally compatible to the target molecule. Obtained imprinted materials are characterized by high specificity, both region- and stereoselectivity and stability. Due to these advantages they are applied in separations (solid-phase extraction, enantiomeric separation, affinity separation, membranes, capillary electrophoresis), sensors, medical diagnostic, organic synthesis and catalysis [2].

In our investigations we have synthesized group of polymers using traditional imprinting method and the new one – surface imprinting. The second technique utilizes water-in-oil emulsion organic-aqueous interface as a recognition field for target molecule giving imprints at the inner cavity surface of obtained polymers [3].

All supports were prepared by suspension polymerization of 4-vinylpyridine (VP), trimethylolpropane trimethacrylate (TMPMA) and acrylonitrile (AN) in the presence of Cu(II) ions and 4-methoxybenzyl alcohol (MBA) as a template. In the surface imprinting method W/O emulsion prepared from Cu(II) ions aqueous solution in organic phase composed of monomers, MBA, solvent (cyclohexanol) and surfmer 4-vinyloxybutylstearate (VOBS) was polymerized (sample B-9 and 10) [4]. Obtained resins were porous with comparable porosity value ascribed to the amount of the aliphatic crosslinker TMPMA (40 wt.%; Table 1). Porosity in swollen state was determined by ISEC method.

Table 1 Characteristics of imprinted polymers

Sample VOBS, wt.%

Water regain, g/g

ZN*, mmol/g Porosity

B-8 -- 3.15 7.20 0.69 B-9 0.3 2.25 5.59 0.68 B-10 0.8 2.29 6.18 0.66

*ZN – nitrogen content

125

To create additional functional groups inside the imprints indirect aminolysis of nitrile groups of AN with hydrazine (at room temperature) and thiourea/ethyl iodide (at 85°C) was carried out according to the scheme (Fig. 1) [5]. Aminoguanidyl ligands were accompanied by carboxyl ligands, created during additional reaction – hydrolysis. The obtained resins were characterized by low modification degree (Table 2).

Fig.1. Scheme of aminolysis of nitrile group

Sorption of Cu(II) ions was performed by the batch method using 5×10-4

and 5×10-3 M solutions of copper(II) acetate in acetate buffer at pH 5.0. The pyridine nitrogen (samples B)/amino groups (samples B-L) to copper (II) molar ratio was 10:1 and 2:1 for samples B-8 and B-9/10, respectively. Cu(II) ions concentration was determined by atomic absorption spectrophotometry (AAS) and sorption properties were expressed in values of Cu(II) loading S (mg/g) and distribution coefficient K (cm3/g). The structures and peculiarities of complexes between metal ion and polymer ligands were studied using FTIR and EPR methods. Table 2 Characteristics of modified resins

Ion exchanger

Water regain, g/g

ZN, mmol/g

ZNH2, mmol/g

ZCOOH, mmol/g

B-8L 2.57 6.1 0.9 0 B-9L 3.74 4.4 0.3 1.5 B-10L 2.42 4.8 0 0.6

Sorption properties of chosen ion exchangers are shown in Figure 2.

Introduction of aminoguanidyl and carboxyl ligands inside the imprint structure increases sorption of Cu(II) ions. One can observed greater influence of carboxyl ones. However, the EPR measurements do not confirm coordination of formed aminoguanidyl ligands by metal ion. Obtained spectra and simulation parameters are characteristic for copper coordination of two or three pyridine nitrogens and oxygen atoms of water molecule or carboxyl groups.

In order to complete properties of molecular imprinted Cu(II) ion-exchangers with aminoguanidyl ligands, their catalytic activity was studied in model reaction of hydroquinone oxidation (H2Q) to p-benzoquinone (Q) in the presence of hydrogen peroxide. Figure 3 presents the catalytic activity of chosen ion exchangers as the loss of hydroquinone (LH2Q) and reaction selectivity (SQ). Even small degree of nitrile groups modification to aminoguanidyl/carboxyl ones on the surface of imprint increases both parameters. It is connected with exchange of hydrophobic interaction to hydrophilic and creation of better environmental conditions during

CN

NH2C NH

SC2H5

P C C

O

P NH NH2 P C NH NH C

NH

NH2

O

P

NH2NH2

-NH3

+H2O

NH

NH NH2

126

catalysis. This effect is greater in case of samples synthesized by surface imprinting (sample B-10).

Fig.2. Sorption (S, mg/g) properties of non-modified and modified imprinted ion

exchangers

Fig.3. Catalytic activity (loss of hydroquinone LH2Q and selectivity SQ in %) of

molecular imprinted resins with coordinated Cu(II) ions

REFERENCES

1. C. Alexander, L. Davidson, W. Hayes, Tetrahedron, 59(2003)2025 2. O. Bruggemann, Adv. Biochem. Eng. Biotechnol., 76(2002)127 3. E. Toorisaka, K. Uezu, M. Goto, S. Furusaki, Biochem. Eng. J., 14(2003)85 4. A. Jakubiak, B. N. Kolarz, J. Jezierska, Macromol. Symp., 235(2006)27 5. A. Jakubiak, I. A. Owsik, B. N. Kolarz, Annals Polish Chem. Soc.

3(3)(2004)955

012

3456

78

B-8 B-8L B-10 B-10LIon exchanger

S, l

ogK

S, mg/g logK

0

20

40

60

80

100

B-8 (0.2) B-8L (0.2) B-10 (0.07) B-10L (0.08)

Catalyst (Cu(II) loading, mmol/g)

L H

2Q, S

Q,%

LH2Q, % SQ, %

127

Ag-NANOPARTICLES IN COSMETIC COMPOSITIONS

A. F. KRIVOSCHEPOV, V. V. NAZAROV, K. I. KIENSKAYA , O. V. YAROVAYA, S.E. MUCHTAROVA*

Mendeleev University of Chemical Technology of Russia,

9, Miusskaya sq., Moscow, 125047, Russia, e-mail: sonoio@mail.ru *OOO “NPF Techkon”

Today one can believe that world market of cosmetic production is packed; however in spite of that technology of them develop permanently. New products appear with improved properties and characteristics and new antioxidants and preservatives are taking into account. Recently hydrosols of metals and metal oxides are widely used as preservatives. Sol-gel technology (nanotechnology) show that properties of small particles are unique and due to this fact that nanoparticles used in the different field of chemical technology and in medicine and in cosmetic. It is known that nanoparticles of CuO and ZnO are using as antibacterial additions in cosmetic creams, gels and lotions, but now the nanoparticles of silver (Ag- Nanoparticles) start to play leading role. Ag represents microelement, which is essential for normal activities of man. Ag possesses antinflammation and antimicrobe action. Here it should be noted that only metallic Ag has the properties, not ionic form of Ag. Due to the elaborations of methods of synthesis of Ag- Nanoparticles is very interesting problem.

Analysis of knows articles show that there are many publications devoted to

synthesis of Ag- nanoparticles, but all of the methods are very difficult and expensive. In present research work we offer a simple way to obtain Ag-nanoparticles based of reaction “silver-mirror”.

2Ag(NH3)2OH + OHC-(CHOH)4-CH2OH→

2Ag ↓ + 4NH4OH + HOOC-(CHOH)4-CH2O

As substrate we have selected the particles of silica dioxide. In this way silver is precipitate on the beforehand-formed Nanoparticles of SiO2. This variant has a some advantages. First if we speak about of cosmetic, this substrate – SiO2 is inert; secondly, hydrosol of SiO2 is stable in acid and alkali media and eventually we have a possibility to control the size of Ag-nanoparticles by varying size of SiO2. Finally we can obtain aggregative stable yellow-brown sol. Colloidal-chemical properties of hydrosols of Ag differ from properties of SiO2-hydrosols. In particular, the hydrosol of Ag is more stable in the presence of electrolyte, but the size of it particles exceed of SiO2 particles and arrange about 70-

128

80 nm. It should be noted that controlling of concentrations of all reagents we could to obtain completely sheeted by Ag nanoparticles of SiO2. In dispersion medium there are no AgNO3 and free SiO2. On the base of these new hydrosols of Ag were prepared some cosmetic composition. They were stable and show antinflammation and antimicrobe action. Moreover, these compositions not need additional preservatives.

129

CLASSICAL AND NONCLASSICAL PROCEDURES FOR THE RESOLUTION OF RACEMIC 1-(PYRIDIN-2-YL)ETHYLAMINE

Jozef DRABOWICZ, Marcin KŁOS

Center of Molecular and Macromolecular Studies, Polish Academy of Sciences,

Department of Heteroorganic Chemistry, Sienkiewicza 112, 90-363 Lodz, Poland

1-(Pyridyl)ethylamines 1 a-c are the most easily available heteroanalogues of 1-phenylethylamine [1], enantiomers of which have found a wide application in asymmetric synthesis as useful chiral auxiliaries.

It is well known that the presence of a nitrogen atom in the aromatic ring strongly modifies physico-chemical properties of the molecule [2,3]. Therefore it can be expected that enantiomers of 1-(pyridyl)ethylamines 1 a-c will have better solvating and coordinating properties. For these reasons, they should be more effective as reagents and ligands in asymmetric synthesis [2,3].

1 a-c

a = 2 b = 3 c = 4

Classical procedures for the resolution of racemic 1-(pyridin-2-yl)ethylamine 1a described in literature and based on the formation of diastereomeric salts with commercially available L-(+)-tartaric acid are not very effective [3,4]. Therefore we are searching for more efficient, classical and nonclassical protocols for the resolution of the racemic mixture of this amine. In this communication the results of experiments on the formation of the diastereomeric salts with enantiomers of mandelic acid, dibenzoyltartaric acid, tert-butylphenylphosphinothio acid and cholic acid as well as a supramolecular complex with cholic acid methyl ester will be presented.

ACKNOWLEDGEMENT This studies are carried out within a framework of the BIO-MAT project: Modern Materials and Biomaterials: Project number: Z/2.10/II/2.6/03/05/U/4/06.

N

CNH2

CH3

H

2

3

4

130

REFERENCES

1. a) I. Togni, L. M. Venanzi, Angew. Chem. Int. Ed. Engl., 33(1994)497 b) P. Braunstein, F. Naud, Angew. Chem. Int. Ed., 40(2001)680

2. a) H. Brunner, H. Fisch, Monatsh. Chem. 119(1988)525 b) H. Brunner, H. Fisch J. Organomet. Chem., 335(1987)15

3. H. Brunner, H. Fisch, J. Organomet. Chem., 335(1987)1 4. a) H. Brunner, M. Niemetz Monatsh. Chem. 133(2002)120;

b) F. R. Keene, M. J. Ridd, M. R. Snow, J. Am. Chem. Soc., 105(1983)7077 c) K. Michelsen, Acta Chem. Scand. A., 28(1974)428 d) O. Cervinka, O. Belovsky, P. Rejmanova, Coll. Czech. Chem. Commun., 38(1973)1358 e) A. Mi, X. Xiao, L. Wu, Y. Jiang, Synth.Commun., 21(1991)2207

131

CHELATING ION EXCHANGERS IN THE SORPTION OF COPPER( II) COMPLEXES WITH ETHYLENEDIAMINETETRAACETIC ACID

Dorota KOŁODYŃSKA, Halina HUBICKA, Zbigniew HUBICKI

Department of Inorganic Chemistry, Faculty of Chemistry,

Maria Curie-Sklodowska University, Maria Curie-Sklodowska Sq.2. 20-031 Lublin, Poland, tel.: +48 (81) 5375736; Fax: +48 (81) 533 33 48, e-mail

address: kolodyn@poczta.onet.pl In the natural environment heavy metal ions in the presence of chelating

agents occur in the form of anionic complexes. The treatment of heavy metal complex-bearing waste waters requires the separation of heavy metals from complexing agents. In conventional processes these complexing agents (e.g. EDTA) are precipitated by strong acids. In the second step heavy metal ions are precipitated by means of sodium hydroxide or calcium oxide or removed on ion exchangers [1,2]. A very important example of ion exchange application is recovery of copper(II) during leaching which is one of copper production stages. Due to small pH (below 2) of waste waters, conventional chelating ion exchangers of functional iminodiacetate and aminophosphonate groups do not practically adsorb copper(II) ions. The special chelating ion exchangers characterized by much greater affinity for copper(II) than for other metal ions were synthesized – Dowex XFS-4195 and Dowex XFS-4196 or Dowex XFS-43084 [3]. Copper(II) can be also removed by means of extraction with hydroxyoximes on the commercial scale from the mine waters as well as from the pyrometallurgical processes. Anionic heavy metal complexes can be also eliminated by means of anion exchangers. In the Cu(II)-EDTA system removal of [Cu(edta)]2- complexes is achieved using polystyrene anion exchangers as well as chelating anion exchangers. On contrary to conventional ion exchangers, chelating ion exchangers are characterized by high selectivity. Their selective properties depend on the kind of functional group, but insignificantly on grain size and other physicochemical properties. Sorption selectivity is particularly affected by mutual position of functional groups, their spatial configuration and steric effects but by matix properties to a smaller degree. Their exchange capacity depends on the number of functional groups and pH of solution. An important feature of macroporous chelating ion exchangers are their better kinetic properties compared to those of the conventional gel ion exchangers of that type.

Of several scores types of selective organic ion exchangers only a few are produced on the commercial scale. These are selective ion exchangers of the following functional groups:

132

FUNCTIONAL GROUP

FUNCTIONAL GROUP FORMULA

Ion exchanger

iminodiacetic

CH N2

COOHCH2COOHCH2 Dowex A-1

Purolite S-930

iminodiacetic and aminoacetic

Wofatit MC-50

amidooxime NC

OH

NH2 Duolite ES-346

aminophosphonic

CH2 NH CH2 POH

OHO

Duolite C-467 Lewatit TP 260 Purolite S-950

thiol −SH Imac TMR

thiourea

NC

NH

H

3+SCH2

Srafion NMRR Lewatit TP 214

In the presented paper the studies onto the sorption of Cu(II) in the presence

of ethylenediaminetetraacetic acid on the chelating ion exchangers Purolite S-930, Diaion CR-20 as well as Lewatit TP 214 were carried out. In order to measure affinity of these complexes, the breakthrough curves were determined using the above mentioned chelating ion exchangers. The exemplary breakthrough curves of Cu(II) complexes with EDTA (in the Cu(II)-EDTA=1:1 and 1:2 systems) on the macroporous chelating ion exchanger Lewatit TP-214 with thiourea groups are presented in Fig.1.

0 2000 4000 6000 8000 100000,0

0,2

0,4

0,6

0,8

1,0

1:1 1:2

c/co

V [cm3]

Fig.1. The breakthrough curves of Cu(II) complexes with EDTA and pH value of effluent on Lewatit TP 214 (in the Cu(II)-EDTA=1:1 and 1:2 systems).

0 2000 4000 6000 80000

1

2

3

4

5

6

1:1 1:2

pH

V [cm3]

CH N2

COOHCH2COOHCH2

N COOHCH2

133

From these breakthrough curves the weight (Dg) and bed (Dv) distribution coefficients as well as the working ion exchange capacities (Cw) of Cu(II) were calculated. The total ion exchange capacities (Ct) were calculated by integration along the curve. The recovery factors (%R) were also determined by means of the static method with the constant phase contact time 3 h (Fig.2 and 3).

As follows from the research results the distribution coefficients as well as the ion exchange capacities of Cu(II) ions for the above mentioned

0

20

40

60

80

100

2 3 4 5 6 7 8 9

S-930

CR-20

TP 214

0

20

40

60

80

100

2 3 4 5 6 7 8 9

S-930

CR-20TP 214

Fig.2. Comparison of the recovery factors (%R) of Cu(II) complexes with EDTA depending on the pH value on Purolite S 930, Diaion CR-20 or Lewatit TP 214 in the Cu(II)-EDTA=1:1system.

Fig.3. Comparison of the recovery factors (%R) of the Cu(II) complexes with EDTA depending on the pH value on Purolite S 930, Diaion CR-20 or Lewatit TP 214 in the Cu(II)-EDTA=1:2system.

%R

%R

pH

pH

134

chelating ion exchangers are differentiated. The differences in affinity of Cu(II) complexes depend on the kind of functional groups of the chelating anion exchangers (Purolite S-930 – iminodiacetic, Diaion CR-20 – polyamine and Lewatit TP 214 – thiourea groups) as well as on the pH value (Fig.2 and 3).

REFERENCES

1. H. Höll, in: Ion Exchange processes: Advances and Applications, eds. A.Dyer, M.J. Hudson, P.A. Williams, The Royal Society of Chemistry, Cambridge 1993

2. A. Dąbrowski, Z. Hubicki, P. Podkościelny, E. Robens, Chemosphere, 56(2004)91

3. Z. Hubicki, A. Jakowicz., A Łodyga, in: Adsorption and its Applications in Industry and Enironmental Protection. Studies in Surface Science and Catalysis, Vol 120, ed. A. Dąbrowski, Elsevier, Amsterdam, New York 1999

135

BIS-PNP-16-CROWN-6 DERIVATIVES AS ION CARRIERS FOR Pb(II), Zn(II), AND Cd(II) TRANSPORT ACROSS TRIACET ATE

CELLULOSE PLASTICIZED MEMBRANES

Cezary A. KOZŁOWSKI*, Jolanta KOZŁOWSKA*, Władysław

WALKOWIAK**, Jacek KOZIOŁ***, Iwona SERGIEL***

*Institute of Chemistry and Environment Protection, Jan Dlugosz University of Czestochowa, 42-201 Czestochowa, Armii Krajowej 13, Poland, Fax: +48 34

3665322. E-mail addresses: c.kozlowski@ajd.czest.pl ** Chemical Metallurgy Division, Faculty of Chemistry, Wroclaw University of

Technology, 50-370 Wroclaw, Wybrzeze Wyspianskiego 27 Street, Poland *** Institute of Biotechnology and Environment Protection, Zielona Góra

University, 21 B Monte Cassino, 65-561 Zielona Gora, jkoziol@ibos.uz.zgora.pl

Macrocyclic compounds such as crown ethers, azacrowns, cryptands, and calixarenes have been well known for selective recognition of specific metal ions [1-3]. Many studies have focused on the determination of the selectivity and efficiency of the carrier-mediated transport of metal ions through organic media into an aqueous receiving phase. In this paper we report a new, highly efficient liquid membrane system containing bis-PNP-16-crown-6 derivatives for the carrier mediated transport of Cd(II) and Zn(II), from chloride and nitrate aqueous solutions.

We prepared of PIMs by physical immobilization: a solution of cellulose triacetate, the ion carrier (1-6), and the plasticizer, o-nitrophenyl pentyl ether in dichloromethane was prepared. The structure of bis-PNP-lariat ethers investigated in the present work is shown in Fig.1 [4]. Investigation of the selective removal of Pb(II), Cd(II) i Zn(II) from aqueous solution using transport across polymer inclusion membranes was studied. The ion carriers, i.e.bis-PNP-lariat ethers derivatives were incorporated into polymer inclusion membranes composed of cellulose triacetate as a support and o-nitrophenyl pentyl ether as a plasticizer. The used bis-PNP-lariat ethers allow to separate metal ions; the selectivity orders were found as follows: Pb(II) > Zn(II) > Cd(II). In the case of diamino-bridged PNP-bis-lariat ether the removal of metal ions was higher at short core. This suggests that formed ion pairs with metal complexes are determined by number of nitrogen atoms in the ring and sidearm of the ligand.

136

n No.

O

O

O

O

O

N

PN

P

NP

NH(CH2)nNHO

OO

O

O

O

O

O

N

PN

P

NP

O

OO

4 6 7 8 10 12

1 2 3 4 5 6

Structures of bis-PNP-lariat ethers

ACKNOWLEDGMENT Financial support of this work was provided by Polish Science Foundation (Grant no. 4T09C030 32).

REFERENCES 1. L. F Lindoy., The Chemistry of Macrocyclic Ligand Complexes, Cambridge

University Press, Cambridge 1989 2. K. Matsumoto, M. Nogami, M. Toda, H. Katsura, N. Hayashi, R. Tamura,

Heterocycles, 47(1998)101 3. N. Parthasarathy, M. Pelletier, J. Buffle, Anal. Chim. Acta, 350(1997)183 4. R. A. Bartsch, R. A. Lee, S. Chun , N. Elkarim, K. Brandt, I. Porwolik-

Czomperlik , M. Siwy, D. Lach, J. Silberring, J. Chem. Soc., Perkin Trans., 2(2002)442

137

Fig.1. The distribution functions for different values of

USING THE “WHITE NOISE” MODEL FOR DESCRIPTION GAS PERMEABILITY THROUGH THE COMPOSITE MEMRANES

I. M. KURCHATOV, N. I. LAGUNTSOV*,

V. N. TRONIN, V. I. UVAROV* Moscow Engineering Physics Institute (State University), Russia,

*JSC “Aquaservice”, Russia, Moscow email: aquaserv@mail.ru

Recently there were publications [1,2] in which the gas transfer asymmetric phenomena in gradient porous media are considered. In [1] reported about the changing of gas permeability of a membrane in some times at change of a flow direction (“the gas flow diode” effect). Moreover in [2] authors report about anisotropy of catalytic activity in cases of feeding gas on different sides of the membrane.

These phenomena may takes place in membranes with at least two layers: first layer with free-molecular flow regime and second layer with smaller pores.

As it shown in [1] “the gas flow diode” effect can be explained using methods of stochastic dynamics The “white noise” model of interactions molecules with inner porous media surface was developed. This model gives distribution function of molecules by their moving directions:

,)

2(

)exp()(

2

Aerf

AAw π

θπ

θ −=

where θ – angle between moving direction of molecule and normal line to the surface of porous layer, A – parameter dependent on surface roughness or clusters on the surface.

Dependence of the distribution function on the parameter A presented on fig.1 (curve 1 plotted at A<<1, and corresponds to isotropic distribution function, curve 2 plotted at A~1, curve 3 at A>>1, curve 4 corresponds to “billiard model” [1]). One can mention that at increasing value of A, probability for molecule to have moving direction perpendicular to surface also increases. It means that projection of mean velocity of molecules to the gas flow direction decrease, but projection to normal line to the surface of porous media increase.

-π/2 π/2 0 θ

138

To describe gas flow through two-layer membrane system of balance equations was concerned. It is shown that anisotropy of permeability depends on parameter A.

Experimental studying of two layer membrane was carried out. An object of investigation in this work was a membrane with two layers. First layer (substrate) was made from boron nitride using self-propagating high-temperature synthesis method. Parameters of first layer: pore diameter – 50 nm, accessible porosity – 38 %, specific surface – 50 m2/g. Second layer was applied using “spin-coating” method and has pore diameter 3 nm. Experimental data was compared with theoretical dependence and good agreement had been found.

The anisotropy of catalytic activity was found on membranes modified by catalytic systems in such a way that on the inner porous media surface was generated nanoclusters of catalytic materials. Thus this phenomenon also can be explained using developed “white noise” model. To explain the anisotropy of catalytic activity collision rate was estimated for different cases of feeding the gas to the membrane. The ratio of collision rates at different sides of feeding can have value of few times.

Work supported by Russian Foundation for Basic Research grant №06-08-01626-a.

REFERENCES

1. I. M. Kurchatov, N. I. Laguntsov et al. Proceedings of the XXI International

Symposium on Physico-Chemical Methods of Separation “Ars Separatoria 2006”, July 2-5, 2006, Torun, Poland, p. 55

2. V. V. Teplyakov, G. I. Pisarev, M. I. Magsumov, M. V. Tsodikov, W. Zhu, F. Kapteijn, Catal. Today, 118(2006)7

139

FUNDAMENTAL SEPARATION PROPERTIES OF MEMBRANE CONTACTOR SYSTEMS

A. YU. OKUNEV, N. I. LAGUNTSOV,

I. M. KURCHATOV

Moscow Engineering Physics Institute (State University), Russia, Moscow JSC “Aquaservice”, Russia, Moscow

email: aquaserv@mail.ru

Operating principle of gas-liquid membrane contactor (MC) is selective sorption of the desired gas components by moving liquid carrier through polymeric membrane. There are two main sorption processes in MC for given gas/liquid system: chemisorption and/or physical sorption. As a rule chemisorption is characterized by high sorption capacity with non-linear isotherm; physical sorption is characterized by linear isotherm and low sorption capacity.

There are two main schemes based on MCs are known: recirculation scheme using at least two membrane contactors (absorber and desorber) connected by liquid to cycle and flow-through scheme that contains at least one MC. Second scheme can be used to desired gas component removal from gas phase or to liquid by gas saturation. Recirculation membrane contactor scheme allows separating gaseous mixtures.

In case of liquid by gas saturation and immateriality of gas to liquid recovery degree main optimization problems are connected with increasing gas to liquid boundary interface masstransfer of desired components and decreasing of absorbed components gradients across liquid channel.

Using of porous membranes usually solves the first part of problem. It is shown, that using of nonporous membranes can increase masstransfer that bonded with nonequilibrium absorption and extraction processes. Mathematical model of nonequilibrium absorption with interface components transformations has been developed. The model applicable for different membrane types and most interesting systems gas-liquid absorbent.

The second problem of maximizing liquid saturation connected with using of low liquid flow rates. The reasons are diffusion of absorbed components across the channel must almost be over to the exit of MC, and all transformation processes in liquid must became near to equilibrium. This processes influence is described by several dimensionless parameters; one of them is Peclet number that characterizes diffusion across the channel to convection along the channel flows ratio. Apparatus solving liquid saturation problem in case of immateriality of gas recovery degree isn’t gas sensible to gas and liquid mutual flows organization.

140

In case of gas purifying from easy soluble component by membrane contactor flows organization became important. Moreover realizing of simultaneous high gas purifying degree and high saturation degree can be realized only on MCs with countercurrent or near to that flows organization and can be achieved in both cases: physical and chemical absorbents.

Thus we can see that low liquid flow rates regimes are interesting to solving both mentioned above separation problems at one stage. At present most researches dealing with membrane contactors not attending to this case.

Mathematical models used in investigation are based on local material balances in liquid, membrane and gas phases, and don’t needed to experimental obtaining of overall masstransfer coefficients and dependences on hydrodynamic flows parameters. They only need on common coefficients such as diffusion coefficients, reaction rate constants an others. These constants can be measured at another system.

Recirculation membrane contactor system has at least one gas input and two gas outputs. Gas mixture feeds in absorber where easy soluble components removing by liquid. Refining of liquid and obtaining of easy soluble components taking place in desorber. To realize this process the chemical potential gradient between absorber and desorber is needed. The gradient can be realized by temperature or partial pressure difference. The first way is perspective for gas-liquid systems with high solubility of desired components in liquid; strong solubility on temperature dependence and in case of sorption isotherm is near to linear. One of these systems it triethylene glycol – water vapor [1]. If one or more of these demands are not satisfied pure temperature difference as process driving force connected with high energy consuming. Moreover in case of sorption isotherm extremely not linear and have lengmuir type – desorption in membrane contactor not effective and it’s desirable to use alternative methods for liquid purifying, for example – electrolysis.

In spite of mentioned restrictions recirculation membrane contactor system with vacuum in desorber and countercurrent flows organization in desorber can provide simultaneous high concentration and extraction degree of desired component of binary gas mixture. To provide this it’s necessary to realize low liquid flow rate regimes and absorber and desorber.

All mentioned above discussions are based on results of numerical and experimental investigations. Numerical methods of masstransfer in MC calculation based on specially developed grid methods [2]. Experimental work have took form of low energy consuming flat sheet countercurrent membrane contactor [3].

Work supported by Russian Foundation for Basic Research grant №06-08-01626-a.

141

REFERENCES

1. V. V. Usachov, N. I. Laguntsov, A. Y. Okunev, V. V. Teplyakov, S. D. Glukhov, Ars Separatoria Acta №2, 2003, Poland, pp. 36-46

2. N. Laguntsov, Yu. Okunev, E. Levin, Book of abstracts, Euromembrane-2004, Hamburg, Germany, S7-P-13

3. A. Yu. Okunev, N. I. Laguntsov, and others, Russian Federation patent on utility model №51898 from 28.10.2005

142

THE INFLUENCE OF STERIC EFFECT AND ALKYL CHAIN LENG TH ON FORMATION Cu(II) COMPLEXES WITH 1-ALKYL-2-

HEXYLIMIDAZOLE

ElŜbieta RADZYMIŃSKA-LENARCIK1, Beniamin LENARCIK2

1Department of Inorganic Chemistry, University of Technology and Life Sciences Bydgoszcz, Seminaryjna 3, 85-326 Bydgoszcz, Poland

2Higher School of Environmental Protection, Fordońska 120, 85–739 Bydgoszcz, Poland

Previously it was demonstrated that the steric effect, due to the methyl or

ethyl group in position “2” of the imidazole ring, favoured the formation of tetrahedral Co(II), Zn(II) and Cd(II) complexes in aqueous solutions [1-3]. That facilitated the transfer of the cations to the organic phase as compared to Ni(II) and other metals [4,5].

The purpose of this work was to investigate the influence of alkyl chain length of the 1-alkyl substituent and the hexyl group in the position “2” on the formation of complexes of Cu(II) with 1-alkyl-2-hexylimidazole, where alkyl = ethyl, butyl and hexyl. 2-Ethylhexanol and chloroform were used as organic solvent. Alkyl group at the nitogen atom do not affect the donor properties of 1,3-diazoles, but only suppress their solubility in water, thus increasing the hydrophobicity of the complexes [6,7].

Generally, the dark-blue complexes were formed during reaction of the organic (chloroform or 2-ethylhexanol) solutions of the ligand (L-1-alkyl-2-hexylimidazole) with Cu(II) nitrates.

Two complexes (ML, ML2) of Cu(II) with 1-alkyl- 2-hexylimidazole passed to the organic phase in each extraction process. Formation of the former is described by equations below:

[CuL]2+ + 2 NO3¯ ↔ [CuL(NO3)2](org)

[CuL2]

2+ + 2 NO3¯ ↔ [CuL2(NO3)2](org)

The values of the stability constants of the investigated complexes were

calculated by numeric method using the Rydberg’s formula [9] and are presented in Table 1 together with data obtained earlier for Cu(II) complexes with 1,2-dialkylimidazole [10-15].

143

Table 1. Stability constants log β1 of Cu(II) complexes with 1,2-dialkylimidazole in aqueous solution (298K, I=0.5 KNO3, HNO3)

Ligand pKa [8] log β1

(potentiometric method)

log β1 (extraction method)

solvent

1,2-dimethylimidazole [10] 8.21 3,70 1-ethyl-2-methylimidazole [11] 8.21 3,52

1-propyl-2-methylimidazole [12]

8.25 3,67

1-butyl-2-methylimidazole [11] 8.18 3,74 1-propyl-2-ethylimidazole 8,03 3,93 [14] 1-butyl-2-ethylimidazole 8,27 3,82 [14] 1-pentyl-2-ethylimidazole 8,31 4,46 [14] 1-hexyl-2-ethylimidazole 8,36 4,15 [14] 1-ethyl-2-propylimidazole 8.27 3,26 [13] 1-butyl-2-propylimidazole 8,35 3,37 [13] 1-hexyl-2-propylimidazole 8.43 3,52 [13] 1-ethyl-2-butylimidazole 8.31 3,39 [15] 1-butyl-2-butylimidazole 8.39 3,44 [15] 1-hexyl-2-butylimidazole 8.47 3,52 [15]

3,51 chloroform - 8.31

3,07 2-ethyl-1-hexanol 3,44 chloroform

8.39 3,43 2-ethyl-1-hexanol 3,78 chloroform

8.47 3,25 2-ethyl-1-hexanol

It was found that the stability constants, log β1 of Cu(II) complexes with

1-alkyl-2-hexylimidazole are lowest as compared to those of the 1,2-dialkylimidazoles in which position “2” is occupied by shorter alkyl substituent (propyl, ethyl or methyl). It is a result of steric hindrance of the butyl group placed close to nitrogen donor atom in the imidazole ring.

REFERENCES 1. B. Lenarcik., K. Kurdziel, Pol. J. Chem., 55(1981)737 2. B. Lenarcik, K. Kurdziel, Pol. J. Chem., 56(1982)3 3. B. Lenarcik, A. Adach, E. Radzymińska-Lenarcik, Pol. J. Chem., 73(1999)1273

144

4. B. Lenarcik, J. Głowacki, M. Rzepka, Sep. Sci. Technol.,14(1979)37 5. B. Lenarcik, K. Kurdziel, R. Czopek, Pol. J. Chem., 65(1991)837 6. B. Lenarcik, B. Barszcz, Pol. J. Chem., 53(1979)963 7. J. Kulig, B. Barszcz, B. Lenarcik, Pol. J. Chem., 66(1992)79 8. B. Lenarcik, P. Ojczenasz, J. Heterocycl. Chem., 39(2002)287 9. J. Rydberg, C. Musikas, R. Choppin, Principles and Practices of Solvent

Extraction, M.Dekker, NY,1992 10. B. Lenarcik, B. Barszcz, J. Chem. Soc. Dalton Trans., 24(1980) 11. B. Barszcz, J. Kulig, J. Chem.Soc. Dalton Trans., (1993)1558 12. B. Barszcz, J. Kulig, J. Jezierska, J. Lisowski, Pol. J. Chem., 73(1999)447 13. E. Radzymińska-Lenarcik, B. Lenarcik, XX-th International Symposium on

Physico-Chemical Methods of the Mixtures Separation “ARS SEPARATORIA 2005” Szklarska Poręba, June 20-23, 2005 p.195

14. E. Radzymińska-Lenarcik, B. Lenarcik, XV-th International Symposium on Physico-Chemical Methods of the Mixtures Separation “ARS SEPARATORIA 2001” Borówno k/Bydgoszczy, June 20-23, 2001 p.258

15. E. Radzymińska-Lenarcik, B. Lenarcik, XXI International Symposium on Physico-Chemical Methods of Separation “ARS SEPARATORIA 2006” Toruń, July 2-5, (2006)117

145

SOLVENT EXTRACTION OF Cu(II) COMPLEXES WITH 1-ALKYL -1,2,4-TRIAZOLE

ElŜbieta RADZYMIŃSKA-LENARCIK1, Beniamin LENARCIK2

1Department of Inorganic Chemistry, University of Technology and Life Sciences

Bydgoszcz, Seminaryjna 3, 85-326 Bydgoszcz, Poland 2Higher School of Environmental Protection, Fordońska 120, 85 – 739 Bydgoszcz,

Poland

The purpose of this work was the calculation of the stability and distribution constants of the Cu(II) complexes with 1-alkyl-1,2,4-triazoles (where alkyl = butyl, hexyl, heptyl, octyl and decyl) from extraction date. The determination of their change with an increase in alkyl chain length was studied too. Toluene was used as organic solvent.

The results of the extraction experiments for all the systems studied are presented as plot of logarithms of the distribution ratio between the aqueous and organic phase vs.pH (log DM = f(pH)) – Figure 1.

-1,5

-1

-0,5

0

0,5

1

4 4,1 4,2 4,3 4,4 4,5 4,6 4,7 4,8 4,9 5 5,1 5,2 5,3 5,4 5,5 5,6 5,7 5,8 5,9 6

pH

log D M

1-decyl1-1,2,4-triazol 1-octyl-1,2,4-triazol 1-heptyl-1,2,4-triazol 1-hexyl-1,2,4-triazol 1-butyl-1,2,4-triazol

Fig.1. Influence of the alkyl chain length in the molecule of 1-alkyl-1,2,4-triazole on the process of extraction Cu(II) by using toluene as a solvent [at 25oC and constant ionic strength of the aqueous solution I = 0.5(KNO3)]

The extraction of Cu (II) complexes with 1-alkyltriazole bases occurs at different pH. This is a separate curve for each system. The curves are shifted towards lower pH values with increasing 1-alkyl chain length. Slopes of the curves are the same. The shapes of curves are similar, so they indicate that one complex is being extracted. The values of the stability constants β1

146

and the partition constants P1 of the investigated complexes were determined by the method of curve-fitting using Rydberg’s formula [1-3].

It was found that the stability constants of Cu(II) complexes with 1-alkyl-1,2,4-triazole in the aqueous phase increased slightly with an increasing in 1-alkyl chain length of the 1,2,4-triazole.The partition constants (Pn) (Figure 2) of the compounds being formed in the water phase depend on the 1-alkyl chain length as well: they increase with increasing chain length.

0

20

40

60

80

100

120

140

160

180

3 4 5 6 7 8 9 10 11Cx

Pn

Cx number of carbon atoms in the 1-alkyl substituent in the molecule of 1-alkyl-1,2,4-triazole

P1 toluene

P2 toluene

Fig.2. Influence of the alkyl chain length on partition ratios (Pn) of Cu(II) complexes with 1-alkyl-1,2,4-triazole by using toluene as a solvent

REFERENCES

1. J. Rydberg, C. Musikas, R. Choppin, Principles and Practices of Solvent Extraction, M.Dekker, NY,1992

2. J. Rydberg, Acta Chem. Scan D., 4(1950)1503 3. F. J. C. Rossotti., H. Rossotti, The Determination of Stability Constants,

McGraw-Hill, NY,1961

147

ADSORPTIVE PROPERTIES OF THE CHABAZITE MODIFIED BY HEXADECYLTRIMETHYLAMMONIUM BROMIDE

Marek MAJDAN, Oksana MARYUK, Agnieszka GŁADYSZ-PŁASKA,

Paweł SADOWSKI

Maria Curie-Skłodowska University, Faculty of Chemistry, 20-031 Lublin UMCS,

Poland; e-mail:marek@hermes.umcs.lublin.pl

INTRODUCTION

There is growing interest in the application of the zeolites and clays modified by cationic surfactants in the removal of toxic inorganic and organic pollutants from the aqueous environment [1-5]. Cationic surfactants ,adsorbed on the zeolite surface in the amount higher than its external cation exchange capacity ECEC, alter cation-exchange ability of the adsorbent to anion-exchange and at the same time enable to preserve of some extent cation-exchange capability of the mineral. In connection with this the common adsorption of cations and anions is possible. In the presented report the adsorptive properties of the chabazite modified by hexadecyltrimethylammonium bromide are described.

EXPERIMENTAL Preparation of the adsorbent

The modified chabazite form was prepared through the equilibration of 100 ml 12 mmol/dm3 HDTMA-Br or HDTMA-Cl aqueous solution with 1 g of Na-chabazite through 4h in the temperature 60°C, filtration of the aqueous phase, washing several times with hot water and drying the solid residue in air. Specific surface areas and pore volumes of chabazite were determined by N2 adsorption (BET method) using ASAP 2405V1.01 instrument (Micrometrics Instrument Corporation). The samples were heated at 200° C and at the pressure 10-3 hPa for 2 h prior to measurements. The measurements were performed at –160°C. Adsorption of chromates and divalent metals

Simultaneous adsorption of chromates and divalent metals was conducted through the equilibration of 100 ml of solution: 5mmol/dm3 K2Cr2O7 (Polskie Odczynniki Chemiczne, pure) + 50 mmol/dm3 MeCl2 (respective metal chlorides kindly provided by Polskie Odczynniki Chemiczne) with 0.1 g of chabazite-HDTMA-Br through 4 h in 23°C, filtration of the solution through paper filter and drying the solid residue in air. The chemical composition of the chabazite surface in

148

50-ty randomly selected points was determined using Scanning Electron Microscopy method (microscope LEO SEM 1430 VP supplied with EDX detector; operating conditions of electron microprobe 20 kV, 80 µA beam current). The concentration of Al, Si, Na, Mn, Co, Ni, Cu, Zn, Cd, Mg, Fe, Cr, C on the chabazite surface was determined using standardless version of SEM method. The electron beam penetrated the samples for about 1µm. Vacuum 10-5 Pa was preserved during measurements. Alternatively the adsorption of MeCl2 on Na-chabazite in the absence of chromates was conducted through the equilibration of 100 ml solution : 50 mmol/dm3 MeCl2 with 0.1 g of Na-chabazite through 4h .

RESULTS AND DISCUSSION

The chemical composition of the chabazite samples loaded with Cr(VI) and Me ions: Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II). It is evident from the data, that the adsorbent has hybrid adsorptive properties. Interesting that common adsorption of carcinogenic chromates and toxic cations is possible. We intentionally selected this group of metals having in mind their toxicity, especially components of metal electroplating wastes: Cr, Ni, Zn, Cu, Cd , known from their potential hazard to human health. Cadmium and chromium show high toxicity to humans and animals [6], whereas copper, nickel and zinc have moderate toxicity. Apart from that nickel and cadmium show phytotoxic properties [7-8]. Manganese is used in several markets. Among them the most important is the steel industry, where it is used as a deoxidising and desulphurising agent. In connection with this the recovery of manganese from the wastes is important.

Table 1. The chemical composition of modified chabazite samples (symbol Me-chabazite-HDTMA-Br refers to the chabazite modified by HDTMA-Br with adsorbed metal Me; the molar/g concentrations of elements, taken as the average values from 50-ty points on the adsorbent surface, are referred to molar/g Al concentration)

Me-chabazite-HDTMA-Br

HDTMA/Al

Na/Al Mg/Al

Si/Al

K/Al Cr/Al Me/Al Fe/Al

Mn 0.361 0.193 0.174 2.70 0.251 0.044 0.176 0.073 Co 0.357 0.202 0.164 2.78 0.300 0.049 0.148 0.243 Ni 0.373 0.158 0.164 2.89 0.434 0.049 0.044 0.152 Cu 0.306 0.092 0.149 2.75 0.363 0.043 0.194 0.055 Zn 0.356 0.010 0.156 2.72 0.345 0.044 0.180 0.082 Cd 0.329 0.187 0.172 2.75 0.234 0.067 0.199 0.091 Na 0.353 0.158 0.186 2.85 0.554 0.166 0.158 0.061

149

CONLUSIONS 1. The adsorption of Cr(VI) on the chabazite surface is very complicated in

nature, but essence of its mechanism is based on the formation of alkylchromates and alkyldichromates. The surfactant cations form positively charged bilayers or micelles able to attract anions from the aqueous phase.

2. The cation-exchange ability of the adsorbent is preserved, so the remarkable adsorption of cations is possible. Among them the highest affinity of Cu(II) and Cd(II) toward unmodified and modified chabazite is noticed.

REFERENCES 1. K. S. Hui, C. Y.H Chao, S. C. Kot, J. Hazard. Mater., 127(1-3)(2005)89 2. M. Majdan, O. Maryuk, A. Gładysz-Płaska, Przem. Chem., 84(10)(2005)755 3. M. Majdan, S. Pikus, Z. Rzączyńska, M. Iwan, O. Maryuk, J. Mol. Struct.,

791(2006)53 4. A. D. Vujakovic, M. R. Tomasevic-Canovic, A. S. Dakovic, V. T. Dondor, Appl.

Clay Sci., 17(2000)265 5. E. Chmielewska, K. Jesenak, K. Gapłovska, Collect. Czech. Chem. Commun.,

68(2003)823 6. E. Alvarez-Ayuso, A. Garcia-Sanchez, X. Zquerol, Water Res., 37(2003)4855 7. Kabata-Pendias, H. Pendias , Trace elements in soils and plants, Boca Raton, FL:

Lewis Publ Inc; 1992 8. M. B. McBride , Environmental chemistry of soils, NewYork: Oxford University

Press, Inc; 1994

150

SELECTIVE SORPTION OF ANTIMONY OXOANIONS BY COMPOSI TE SORBENTS WITH HYDROUS OXIDES OF CERIUM AND ZIRCONIU M

Eva MISTOVA, Martina TELECKA, Helena PARSCHOVA, Ludek JELINEK,

*Ferdinand SEBESTA

Department of Power Engineering, ICT Prague, Czech Republic *Department of Nuclear Chemistry, CTU Prague, Czech Republic

eva.mistova@vscht.cz

Antimony occurs in natural waters in a variety of forms including inorganic and organic forms of Sb(III) and Sb(V). Toxicity of inorganic antimony is much greater than that of organic antimony species. The Sb(III) is more toxic than the oxidized Sb(V) [1,2].

There are several different methods for selective separation of Sb (as cation or oxoanion) from water solutions, e.g. sorption by chelating synthetic resin, different types of biosorbents and sorption on inorganic sorbents (as hydrous oxides of Fe, Al, etc.) [3-10].

In this work composite sorbents whit hydrous oxides of cerium and zirconium were used for selective removal of Sb oxoanion. Sorbent CeO2.nH2O/XAD-7 is composite of nonionogenic sorbent Amberlite XAD-7 and cerium oxide (made at Department of Industrial Research in Tohoku, Japan). Sorbent ZrO2.nH2O/PAN is composite of zirconium oxide and polyacrylonitrile matrix (made in Department of Nuclear Chemistry, CTU Prague, Czech Republic). Both sorbents have amphoteric character. Prior to use, sorbents were conditioned with acid or hydroxide.

Experiments were carried out by equilibrium batch and dynamic column sorption. For the batch experiments concentration of Sb(III) and Sb(V) in the feed solution was 1-5 mg/L and 1-25 mg/L, respectively. Concentration of chlorides and sulfates was 100-1000 mg/L in both cases. For the dynamic column sorption the concentration of Sb(V) and Sb(III) in the feed solution was 1-5 mg/L and concentration of chlorides and sulfates was 100 mg/L. The experimental pH values were 3.5, 6 and 9. The effects of pH, concentration of Sb and accompanying anions in the feed solution were studied.

Sorption of Sb(III) was very successful, during the equilibrium experiments both sorbents removed 96-99% of Sb(III) oxoanions from feed solution (pH = 6) which contained 5 mg/L of metal, 100 mg/L of Cl- and SO4

2-. When the concentration of sulfates and chlorides in the feed solution was increased from 100 mg/L to 1000 mg/L at pH = 6, the sorption capacities of the studied sorbents were still very good (removal of about 97%).

Sorption of Sb(V) was very successful too, during the equilibrium experiments both sorbents removed 96-99% of oxoanions Sb(V) from feed solution (pH = 3.5) which contained 1-25 mg/L of metal, 100 mg/L of Cl- and SO4

2-. When

151

the concentration of sulfates and chlorides in the feed solution was increased from 100 mg/L to 1000 mg/L at pH = 3.5 and 6 and the concentration of Sb(V) was 25 mg/L, the sorbent CeO2.nH2O/XAD-7 removed about 66% of Sb from the feed solution, while the sorbent ZrO2.nH2O/PAN removed about 97%.

The dynamic column experiments were performed whit sorbent CeO2.nH2O/XAD-7. The sorption capacities for both forms of Sb were very high (about 6.5g/L for Sb(V) and 15g/L for Sb(III)), but the desorption of antimony was very difficult.

ACKNOWLEDGEMENT

This work was carried out with financial support of Research proposal (MSM 6046137304) from Ministry of Education, Youth and Sports of the Czech Republic.

REFERENCES

1. H. Remy, Anorganická chemie, SNTN Praha, 1972 2. P. Pitter, Hydrochemie, VŠCHT Praha,2nd edition, 1990 3. Z. Matějka, H. Parschová, L. Jelínek, E. Mištová, P. Ruszová, F. Šebesta, J. Ion.

Exch., 14(2003)237 4. Z. Matějka, H. Parschová, P. Ruszová, L. Jelínek, P. Houserová, E. Mištová, M.

Beneš, M. Hrubý, Fundamental and Applications of Anion Separation, Abstracts of Papers, 222nd ACS National Meeting, Chicago, IL, United States, August 26-30, 2001

5. U. Schilde, E. Uhlemann, React. Polym., 22(1994)101 6. M. Abe, T. Kataoka, T. Suzuki, New developments in ion exchange, Tokyo,

1991 7. T. Peréz-Corona, Y. Madrid, C. Cámara, Anal. Chim.Acta, 345(1997)249 8. Z. Matějka, P. Ruszová, H. Parschová, L. Jelínek, Y. Kawamura, Advances in

Chitin Science 6, 213-216, NTNU Trondheim 2002 9. N. Khalid, S. Ahmad, A. Toheed, J. Ahmed, Appl. Radiation and Isotopes,

52(1999)31 10. M. Kang, T. Kamei, Y. Magara, Water Res., 37(2003)4171

152

SORPTION STUDIES FOR SOME HEAVY METALS BY ACRYLIC CHELATING RESINS

Violeta NEAGU*, I. PLESCA*, Nalan KABAY** , M. YUKSEL**

* “Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda

41 A, Iasi, Romania ** Ege University, Chemical Engineering Department, Faculty of Engineering,

35100 Izmir, Turkey

Heavy metals are the main hazardous non-degradable substances in the aquatic environment. Their accumulation makes development of new and efficient methods as well as performance materials for metals removal from water supplies. The latest tendency is to synthesize chelating resins rather than to consider removal of complex species by conventional ion exchangers. The future role of chelating polymers in water treatment for human consumption, industrial uses or environmental protection is of prime importance and, in spite of considerable efforts to develop new chelating resins, their practical use is limited yet by the kinetics and by accessibility problems of the ligand.

The aim of this study is to synthesize some chelating resins with improved sorption properties of heavy metals. The resins were performed by chemical transformation of acrylic networks based on acrylonitrile : vinylacetate : divinylbenzene copolymers in the bead form with ethylenediamine in the presence of water when aminolysis – hydrolysis of nitrile groups and hydrolysis of acetate groups occur. The yielded compounds were characterized by good values of their volume and weight capacities.

The acrylic networks were synthesized by the aqueous suspension copolymerization of acrylonitrile, vinylacetate and divinylbenzene in the presence or absence of toluene as a diluent with various amounts of vinylacetate monomer.

The sorption properties toward several heavy metals [Cu(II), Co(II), Zn(II)] were performed by batch method using both unary and binary metal solutions. Effect of the contact time and counter ions of metal cations on their retention capacities were investigated.

The yielded chelating resins showed high metal retention capacity values and good selectivity for Cu(II) ions in the binary mixture of Cu(II) + Co(II) and for Zn(II) ions in Cu(II) + Zn(II) one from nitrate salts.

153

NOVEL ASYMMETRIC MEMBRANES BASED ON POLYAMIDEIMIDE FOR ORGANIC SOLVENT NANOFILTRATION

V. V. PARASHCHUK1, A. V. VOLKOV1, Yu. P. KUZNETSOV2, S. V. KONONOVA2, D. V. DMITRIEV3, L. I. TRUSOV3, V. V. VOLKOV1

1A.V. Topchiev Institute of Petrochemical Synthesis Russian Academy of Science,

Moscow, Russia 2Institute of High Molecular Compounds Russian Academy of Science, St.-

Petersberg, Russia 3APCT “ASPECT”, Moscow, Russia

The effective recovery and re-use of chemicals (solvents and catalysts) in

industrial processes can be achieved by using of organic solvent nanofiltration (OSN). Moreover, OSN is more promising separation method due to absence of phase separation and energy saving. Unfortunately, the application of the membranes based on polymeric materials in this area is still limited.

In this work, new membranes based on poly(diphenyloxideamide-N-phenylphthalimide) (PAI) were proposed for OSN applications. This polymer material is insoluble in wide range of organic solvents except N-methyl-2-pyrrolidone and ethanolamine. PAI-membranes have a finger-shaped porous structure of the support layer and thin selective top-layer with the thickness about 2 µm. Based on nanopermporometry analysis, the maximum of pore size distribution corresponds with the Kelvin diameter of about 1.5 nm (condensed vapor – n-hexane).

N

The nanofiltration characterizations of PAI-membranes were carried out in the set-up with two dead-end filtration cells at room temperature and pressure up to 20 bar; the effective membrane surface area was 3.32× 10−3 m2. The permeabilities of methanol, ethanol and acetone (Fig.1) exceed more than 1.5 times the ones for industrial nanofiltration membranes (MPF-44, MPF-50, Membrane D, Desal-5-DK and N30F). At the same time, PAI membranes show high retention of Remazol Brilliant Blue R (MW 626.5 Da) in methanol (96%), ethanol (90%) and acetone (84%).

154

3,4

1,4

5,5

0

1

2

3

4

5

6

7

methanol ethanol acetone

Per

mea

bilit

y, k

g/m

2 h b

ar

Fig.1. Permeability of different organic solvents

The membranes show stable nanofiltration characteristics and mechanical

stability up to 5 bar. When the transmembrane pressure is increased up to 10 bar, the membrane compaction takes place due to the collapse of finger-shaped pores in the support layer; ethanol permeability decreases to 0.45 kg/m2h·bar.

155

SORPTION AND SEPARATION OF HEAVY METALS FROM ETHYLENEAMINE COMPLEXES

Helena PARSCHOVA, Zdenek MATEJKA, Eva MISTOVA

Institute of Chemical Technology, Department of Power Engineering

Czech Republic, Prague 6, 166 28 (helena.parschova@vscht.cz)

The methods of waste water purification used by the chemist are for

example filtration, sedimentation, reverse osmosis and ion exchange. The ion exchange presents one possibility for the purification of waste water

polluted by heavy metals. This work is concerned with the study of sorption and separation of heavy metals (copper, zinc and nickel) from ethyleneamine complexes (EDA, DETA, TETA and TEPA).

The selective removal of heavy metal cations requires special resins to be used. The following resins were used in the experimental study:

a) oligo(ethyleneamine) resins b) picolylamine resin c) iminodiacetate chelating cation exchanger d) carboxylic cation exchanger e) sulphonic cation exchanger During the experiments effects of metal concentration and flow rate were

studied. Loading solution contained 1 - 4 mmol/L of ethyleneamine complex and 1 mmol/L of metal. The flow rate of solution was 6 or 18 BV/h. The breakthrough concentration of metal was 1 mg/L. The regeneration consisted of two steps. In the first step 3 BV of 2mol/L HCl was applied and consequently 5BV of 1 mol/L NaOH was applied in the second step. The regeneration flow rate was 3 BV/h. The metals were analyzed by AAS. The values of EDA concentration were analyzed by ion exchange chromatography.

The first part of the study was concerned with the sorption of heavy metals from ethylenediamine complex. Copper, zinc and nickel were chosen for the sorption experiments.

The experimental results show that sulphonic, carboxylic and iminodiacetate cation exchangers are effective for the sorption but oligo(ethyleneamine) resin showed very low efficiency.

The influence of solution flow rate in the range of 6-18 BV/h on the breakthrough capacities was determined. The breakthrough capacities of cation exchangers are in the majority of cases not influenced by the solution flow rate because their sorption rate is high enough. On the other hand the sorption on picolylamine resin is effective only at flow rate 6 BV/h.

The effect of pH value on the sorption capacity in the range of 5 to 8 is following: The breakthrough capacities are increasing with increasing pH value.

156

The uptake of heavy metals by oligo(ethyleneamine) resins is based on the coordination bond of heavy metal cation to N-atom of functional group in the free base form. The application of oligo(ethyleneamine) resins in the free base form is not efficient for sorption of Cu2+ and Ni2+. The breakthrough capacities were very low (0.01 - 0.06 eq/L). The sorption is efficient only for Zn2+. The breakthrough capacities were the highest for resins with tetraethylenepentamine functional group (0.24 - 0.3 eq/L). These resins achieve very low sorption efficiency, but separation of zinc from EDA on oligo(ethyleneamine) resins at solution pH 5 – 6,5 is effective.

The uptake of heavy metals on various cation exchange resins proceeds predominantly through electrostatic attractive forces (between the negatively charged resin's functional group and positively charged metal cation). But on carboxylic cation exchanger and on chelating iminodiacetate cation exchange resin also the coordination of heavy metal cations to N- and/or O- atoms of resin's functional groups contributes to the uptake of metal by ion exchanger. Theoretically, two coordination bonds of heavy metal cation can be consumed by O-atoms of carboxylic cation exchanger, while three coordination sits of heavy metal cation could be consumed by iminodiacetate moiety (2 bonds to O-atoms and 1 bond to N-atom).

Experimental results show that carboxylic cation exchanger achieve very good sorption capacities (0.84 – 3.16 eq/L). The results of effluent analysis showed that separation of metal from EDA is not effective because effluent contained 0.5mmol/L EDA.

The sorption on sulphonic cation exchanger is effective (0.3 - 1.42 eq/L). Strongly acidic cation exchanger takes up metal from EDA ligand in the cation complex [Me (EDA)x]

2+. Thus, separation of metal from EDA is not effective. Iminodiacetate chelating cation exchanger resin is effective (1,14 - 1,72

eq/L) in the three sorption forms (H+, Na/H and Na+). IDA-resin takes up heavy metals quantitatively, but the separation from EDA is only partial. In the early phase of the sorption run, copper is taken up as Cu-EDA cation complex. As the resin loading by metal continues, the separation degree is improved.

The sorption on picolylamine resin in the protonated form is effective and the breakthrough capacity is 0.11eq/L. The substantial improvement of separation is achieved on picolylamine type resin in the protonated form at solution pH 4. The characteristic feature of this type of functional group is its ability to co-ordinate metals even in the protonated form. The pH value of an effluent is then constantly in the acidic range and copper is sorbed from solution quantitatively as free cation with the total separation from EDA-ligand.

The second part of the study was concerned with the sorption of copper, zinc and nickel from solutions containing these ethyleneamine complexes: EDA = ethyleneamine, DETA = diethylenetriamine, TETA = triethylenatetramine, TEPA = tetraethylenepentamine.

157

Heavy metals are taken up completely from the solution by cation exchangers. The breakthrough capacity decreases with increasing chelating ability of ethyleneamine complexes in the solution.

The financial support from Research Plan MSM CZ 6046137304 is gratefully appreciated.

REFERENCES

1. J. Kahovec, Chelatující a komplexonové polymery, Cemické listy / svazek 75, 1981

2. R. Přibyl, Komplexometrie, SNTL, Praha 1977 3. E. A. Martel, M. Calvin, Chemie kovových chelátů, ČSAV, Praha 1959 4. J. Cross, Water Purification : What Every Engineer Should Know, Chemical

Technology Europe, June/July 1994 5. K. C. Jones, R. R. Grinstead, Properties and Hydrometallurgical Applications of

Two New Chelating Ion Exchange Resins, Chemistry and Industry, 1977 6. Z. Matějka, D. Behner, L. Outratová, H. Parschová, Sorption of Heavy Metals

form Hydroxycarboxylate Complexes by Acrylamide Sorbents having Oligo(ethyleneamine) Moieties; IEX’ 93 Int. Conference on Ion Exchange Processes, April 1993, The North East Wales Institute, Wrexham, U.K.

7. Z. Matějka, H. Parschová, P. Roztočil, Sorption and Separation of Heavy Metals in the Presence of Complexing Agents; Proc. ICIE’95 Int. Conf. on ion Exchange, December 1995, Takumatsu, Japan

158

THE SOLVENT EXTRACTION OF COPPER (II) FROM CHLORIDE SOLUTION BY OXIME OF HYDROPHOBIC 2- AND 4-PYRIDYL K ETONE

Karolina KLONOWSKA-WIESZCZYCKA, Andrzej OLSZANOWSKI, Anna PARUS, Barbara ZYDORCZAK

Institute of Chemical Technology and Engineering, Poznań University of

Technology, Pl. Skłodowskiej – Curie 2, 60 – 965 Poznań, Poland

The solvent extraction techniques are often applied to remove copper (II) from acidic aqueous solutions. Oximes of hydrophobic pyridineketone could be the new group of extractants for the recovery of metals from aqueous solutions. The pyridineketoximes can form complexes with ions of zinc, cadmium, nickel and copper. The pyridineketoximes can form complexes with metals by solvating or/and chelating mechanisms.

The aim of this work was the synthesis of hydrophobic 2- and 4-pyridineketoximes and the extraction studies of copper(II) from chloride solutions with the synthesized model pyridineketoximes. The alkyl group of the synthesized model pyridineketoximes contains 8- 12 of carbon atoms. The extraction of copper(II) chloride was carried out by constant water activity aw = 0.835 (constant total concentration of ions and `molecules dissolved in aqueous solution σ = 8.0 M). NaCl, LiNO3 and NaNO3 were used to adjust the activity of water. In all experiments the pH of the aqueous phase was closed to 3.5. The studies were carried out by constant copper (II) concentration equal to 0.01 M. The concentration of extractant in the organic phase was changed from 0.01 to 0.1 M. Chloroform was used as the diluent.

The obtained results indicate that the ability of pyridineketoximes to extract copper depends significantly upon the number of alkyl group and the position of oximes group in the pyridine ring. The hydrophobic 2-pyridineketoximes are the stronger extractants of copper than the 4-pyridineketoximes and the extraction percentage does not depend on chloride ions concentration. For hydrophobic 4-pyridineketoximes the extraction percentage were increased with the increase of chloride ions concentration.

159

THE SOLVENT EXTRACTION OF ZINC (II) AND CADMIUM (II ) FROM CHLORIDE SOLUTION BY OXIME OF HYDROPHOBIC 2-PYRIDYL

KETONE

Karolina KLONOWSKA-WIESZCZYCKA, Andrzej OLSZANOWSKI, Anna

PARUS

Institute of Chemical Technology and Engineering, Poznań Universty of Technology, Pl. Skłodowskiej – Curie 2, 60 965 Poznań, Poland

The solvent extraction is one of the important techniques for the separation

and recovery of metals in many industrial fields. Although many extractants are known and used in industry, the research of finding new extractants is always important. Pyridineketoximes could be the interesting group of a new extractant agent. The pyridineketoximes can form complexes with many metals ions, for example: zinc, cadmium, nickel and copper, in the broad range of pH [1,2]. These compounds can form solvating and chelating complexes with ions of metals. The formation of pyridineketoximes complexes with metals depend on several factors such as nature of organic solvent, concentration of the metal cations and acidity of the aqueous phases [3,4].

The aims of this work were the synthesis of hydrophobic derivatives of 2-pyridineketoximes (with octyl, decyl and dodecyl group) and the studies of the zinc(II) and cadmium(II)) extraction from chloride solutions. The extraction experiments were carried out at constant water activity (aw = 0,8352) for pH range 2,0 – 8,0, different ionic strength (I =1 and I=4), chloride ions concentration range 0–4M, and the different ligand concentration. NaCl, LiNO3 and NaNO3 were used to adjust the activity of water. NaCl and NaClO4 were used to adjust the ionic strength.

The obtained results indicate than all synthetized hydrophopic pyridineketoximes extracted zinc(II) and cadmium (II) from chloride solution, at the broad range of chloride concentration. In the excess of ligand to metal, the extraction did not depends on the chloride concentration.

The degree of extraction of zinc slightly depends on the pH of the aqueous phase. Water could be used as the reextraction agent.

REFERENCES

1. M. Carcelli, P. Cozzini, R. Marroni, Inorg. Chim.Act., 285(1)(1999)138 2. J. C. Milios, T. C. Stamataos, S. P. Perleps, Polyhedron, 25(2006)134 3. M. K. Jha, V. Kumar, R. J. Singh, Solv. Extr. Ion Exch., (2002)389 4. J. Budka, F. Hampl, F. Liska, P. Scrimin, P. Tecilla, U. Tonellato, J. Mol. Catal.,

104(1996)201

160

GOLD (I) UPTAKE BY FUNCTIONALISED VINYLBENZYL CHLORIDE-DIVINYLBENZENE COPOLYMER BEARING AMINO

GROUPS

Magdalena PILŚNIAK , Andrzej W. TROCHIMCZUK, Wiesław APOSTOLUK

Faculty of Chemistry, Wroclaw University of Technology Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland

e-mail: magdalena.pilsniak@pwr.wroc.pl

Gold can be effectively extracted from various sources such as sulphidic and carbonaceous ores and jewelry scrap by using cyanide leaching. This process is not ideal on account of toxicity of cyanide. An attractive alternative to cyanide as a lixiviant for gold is ammonia. Ammonia is less toxic than cyanide, easily regenerated by evaporation and relatively inexpensive [1]. Thus, the process of leaching with ammonia solutions has been studied and developed in recent years. There is growing interest in preconcentration, recovery and separation of noble metals from ammonia solutions. The active carbons have been used for Au(NH3)2

+ uptake from this solutions [2]. So far, there is only one report concerning the application of polymeric resins in recovery of cationic complexes of gold. It is our work, which presented synthesis of resins with carboxyphosphonate ligands and their use in the sorption of gold from ammonium buffer [3].

Ion exchange/coordination resins are very useful in the removal of noble ions from various aqueous solutions. These materials are used when the concentration of metal ions in the solution is small and the resins display preferential sorption towards chosen ions. The application of polymeric materials is promising for Au(NH3)2

+ sorption due to a small concentration of gold (4 mg/dm3) and large quantities of copper (15 g/dm3) in solution obtained by ammonia leaching of gold-bearing raw material.

In this study, we decided to obtain resins with ligands containing donor atoms: nitrogen and sulfur. Noble metals form stable complexes with resins containing N- and S- donor atoms in their functional groups. The polymeric resins were synthesized by reacting amine with vinylbenzyl chloride-divinylbenzene copolymer at room or reflux temperature (conventional method) and in a microwave reactor (microwave method). These are the following resins: guanylthiourea resin (1), 1-methylimidazole resin (2), 2-mercapto-1-methylimidazole resin (3 and 4), 1,2-dimethylimidazole resin (5), 1-(3-aminopropyl)imidazole resin (6), 4-(3-aminopropyl)morpholine (7) resin and 4-tert-butylpyridine resin (8). VBC/DVB copolymer with expanded gel structure, containing 2 wt % of DVB was obtained using suspension polymerization. The obtained resins were characterized using FTIR and elemental analysis for nitrogen, sulphur and chlorine.

161

Table 1. Characteristics of the polymeric resins

Resin No Water regain [g/g]

Nitrogen content

[mmol/g]

Sulfur content

[mmol/g]

Chlorine content

[mmol/g] 1 0.64 8.07 2.87 0.00

2 4.00 6.20 0.00

3 0.51 4.20 2.19 2.05

4 0.34 7.35 4.48 0.00

5 4.76 6.11 0.00

6 0.33 6.10 1.90

7 0.70 6.35 0.00

8 3.96 2.27 0.22

These polymeric materials were used for the removal of gold from

ammonium buffer (0.1-100 g/dm3 NH3·H2O, 0.05-50 g/dm3 (NH4)2SO4), containing 21.57 mg/dm3 of Au (I). The best sorption towards Au(NH3)2

+ from ammonium buffer, containing 100 g/dm3 NH3·H2O and 0.5 g/dm3 (NH4)2SO4, displayed the resins, which were obtained by microwave modification.

REFERENCES

1. K. N. Han, M. C. Fuerstenau, Int. J. Miner. Process., 58(2000)369 2. Q. Xu, X. Meng, K. N. Han, Miner. Metall. Process., (1996)141 3. M. Pilsniak, A. W. Trochimczuk, e-Polymers, P_018(2006)

162

WATER SOFTENING BY DONNAN DIALYSIS USING INTERPOLYMER AND HOMOGENEOUS CATION-EXCHANGE MEMBRANES

Gryzelda POŹNIAK

Wrocław University of Technology, Faculty of Chemistry WybrzeŜe Wyspiańskiego 27, 50-370 Wrocław, Poland

gryzelda.pozniak@pwr.wroc.pl

INTRODUCTION Development of efficient techniques for separation and recovery of ions has

stimulated for testing of various membrane methods. Donnan dialysis (DD) is a useful membrane process for two reasons: it is not technically advanced process as well as it saves energy. In the DD process, an ion exchange membrane, e.g., cation exchange one, separates two electrolytes: the feed containing cations that should be removed and the receiver with relatively high concentration of the driving cation. The chemical potential gradient of the electrolytes on the both sides of the membrane causes the flux of the driving ion from the receiving solution to the feeding phase that results in the transport of the other ion in the opposite direction. As a result, retentate with a different ionic composition is obtained; undesired ions are replaced by neutral one [1]. Donnan dialysis is used as the pretreatment technique in wastewater and drinking water treatment, and in hydrometallurgical operations [2-5].

Ion-exchange membranes obtained by chemical modification of interpolymer polyethylene/poly(styrene-co-divinylbenzene) system (PE/poly(S-co-DVB)) have excellent osmotic and mechanical stability, and have high selectivity and good ion-exchange properties. These membranes have found application in fuel cells [6], diffusion dialysis [7,8], Donnan dialysis and /or Poźniak dialysis [9] or pervaporation [10] processes.

Among the attractive properties of the engineering thermoplastic poly(ether ether ketone), good solvent resistance, high thermo-oxidative stability and good mechanical properties are significant [11]. In the last time, considerable effort was made to modify its chemical nature while maintaining its excellent physical properties to find membrane applications [12,13].

The aim of this work is compare two kind of cation exchange membrane with sulfonic groups: membrane KESD from sulfonated interpolymer (PE/poly(S-co-DVB)) and SPEEK from sulfonated poly(ether ether ketone), in Donnan dialysis of calcium and magnesium ions.

163

EXPERIMENTAL

Preparation of KESD membrane The extruded film of PE/poly(S-co-DVB) interpolymer was used as

membrane matrix for further modification. The low-density PE (Petrochemia Blachownia S.A, Poland) was applied in these studies. Interpolymer contains 30%wt of copolymer styrene and divinylbenzene cross-linked with 1 wt% of DVB. The details on interpolymer preparation are described in our previous papers [14-16]. The KESD membrane was prepared by sulfonation of the interpolymer within 30% vol. solution of chlorosulfonic acid in 1,2-dichloroethane for 4 hr at room temperature and then hydrolyzed with 20 wt% NaOH aqueous solution for 18 hr.

CH CH2 CH CH2

CH CH2SO3 Sulfonated poly(styrene-co-divinylbenzene)

Preparation of SPEEK membrane

Sulfonic groups into poly(ether ether ketone),Victrex 450 PR, were introduced by sulfonation with sulfuric acid (molar ratio of polymer to acid equal to 1:57) [17]. The reaction was carried out at 500C during 4 hours. Dried SPEEK was dissolved in N,N-dimethylformamide (15 wt.%) The solution was cast onto a glass plate, then dried at ambient conditions and kept under vacuum at 1000C for 24 hr to remove the residual solvent.

O O

SO3

C

O

n

Sulfonated poly(ether ether ketone)

Characterization of membranes The ion exchange capacity of the membranes was determined by acid-base

titration [15,17]. Membrane swelling in water was determined gravimetrically by weighting wet and dry samples.

164

Transport properties All DD experiments were carried out using a two-chamber laboratory

dialyser. The membrane of active area of 4.9 cm2 separated 0.1 M solution of CaCl2 or MgCl2 or their mixture (feed solution) from 0.5 or 1 M KCl (receiving solution). The volumes of the chambers were the same and equal to 35 cm3. The feed and receiving solution were sampled at regular time interval during 20 h. Total metal concentrations were determined using atomic absorption spectrophotometer (AAnalyst 100, Perkin Elmer).

RESULTS AND DISCUSSION

Chemical properties of both types of membranes are similar (Table 1).

Table 1. Characteristics of the membranes

Kind of membrane Ion exchange capacity

mmol/g

Degree of swelling

%

KESD 1.98 78

SPEEK 1.76 68

The compared membranes differ in physical structure: when KESD

membrane consists of ion exchange sites (copolymer S and DVB with sulfonic groups serves as the cross-linked polyelectrolyte) distributed within the inert PE matrix [14], the SPEEK membrane is coherent ion exchange gels (Fig.1).

(a) Homogeneous membrane

Inert phase containingnon charged polymermatrix

Gel phase containingionogenic groups

(b) Interpolymer membrane Fig.1. Conceptualized distribution of ionogenic groups within cation exchange

membranes. When one compares the transport properties of such ions as Ca, Mg

and K for both membranes one realizes that the better is homogenous membrane SPEEK (Tables 2 and 3).

165

Table 2. Transport properties of the tested membranes

Kind of membrane

Molar ratio KCl/CaCl2 or MgCl2

106 x Flux of Ca

mol/m2s

106 x Flux of Mg

mol/m2s

106 x Flux of K

mol/m2s

Membrane selectivity*

%

Final time of

dialysis**

min 0.5/0.1 1.95 - 3.48 56 610

KESD 1.0/0.1 2.85 - 4.44 64 418 0.5/0.1 4.23 - 5.42 78 281

SPEEK 1.0/0.1 7.42 - 8.66 86 160 0.5/0.1 - 1.05 1.93 44 1130

KESD 1.0/0.1 - 1.94 3.75 52 613 0.5/0.1 - 3.58 5.88 61 332

SPEEK 1.0/0.1 - 6.44 8.30 78 185

• *Selectivity of membrane - ratio of Ca (or Mg) flux to K flux • **Final time of dialysis – time of 100% recovery of Ca or Mg

Magnesium and calcium recovery with homogeneous SPEEK membrane was over three times greater than that of interpolymer KESD under similar conditions. Selectivity of membrane SPEEK is about 20% greater than KESD one; while Ca and Mg is more effectively removed.

Table 3. Transport properties of the tested membranes (1.0M KCl/0.1M mixture of CaCl2+MgCl2)

Kind of

membrane

106 x Flux of

Ca

mol/m2s

106 x Flux

of Mg

mol/m2s

Membrane

selectivity*

%

Final time

of dialysis**

min

KESD 1.49 1.23 39 (Ca) 32 (Mg) 399 (Ca) 483 (Mg)

SPEEK 3.71 3.68 41 (Ca) 41 (Mg) 160 (Ca) 162 (Mg)

In the case of 0.1 M mixture of CaCl2 and MgCl2 the fluxes of both cations are comparable. The same similarities were observed for times of both cations removal and membrane selectivity.

The difference in transport properties between both membranes results from various structures of the membranes (Fig.2).

166

Ca

2+Mg

2+

or

( a )

Feed Side

Homogeneous membrane

ReceivingSide

K+

Ca

2+Mg

2+

or

K+

Interpolymer membrane

ReceivingSide

( b )

Feed Side

Movement of ions through ionogenic groups

Movement of ions through inert phase Fig.2. Counter-transport of Ca2+ or Mg 2+ and K+ through cation exchange

membranes.

ACKNOWLEDGEMENTS Financial support of this work was provided by the Polish Committee for Scientific Research - grant no. 3 T09B 047 28.

REFERENCES

1. R. M. Wallace, Ind. Eng. Chem., Process Des. Dev., 6(1967)423 2. R. L. Wilson, J. E. DiNunzio, Anal. Chem., 53(1981)692 3. M. Hichour, F. Persin, J. Sandeaux, C. Gavach, Sep. Purif. Technol., 18(2000)1 4. Y. Cengeloglu, E Kir, M. Ersoz, T. Buyukerkek, S. Gezgin, Coll. Surf. A:

Physicochem. Eng. Aspects, 223(2003)95 5. D. E. Akretche, H. Kerdjoudj, Talanta, 51(2000)281 6. M. Grzebyk, G. Poźniak, Sep. Purif. Technol., 41(2005)321 7. G. Poźniak, W. Trochimczuk, Angew. Makromol. Chem., 92(1980)155 8. G. Poźniak, W. Trochimczuk, Angew. Makromol. Chem., 104 1982)1 9. G. Poźniak, W. Trochimczuk, J. Membr. Sci., 49(1990)55 10. W. Kujawski, G. Poźniak, Sep. Sci. Technol., 40(2005)1 11. M. T. Bishop, F. E. Karasz, P. S. Russo, K. H. Langley, Macromolecules,

18(1985)86 12. L. Li, J. Zhang, Y. Wang, J. Membr. Sci., 226(2003)159 13. S. Xue, G. Yin, Eur. Polym. J., 42(2006)776 14. G. Poźniak, W. Trochimczuk, Angew. Makromol. Chem., 127(1984)171 15. W. Kujawski, G. Poźniak, Sep. Sci. Technol., 39(2004)2137 16. W. Kujawski, G. Poźniak, Q. T. Nguyen, J. Neel,, Sep. Sci. Technol.,

32(1997)1657 17. R. Y. M. Huang, P. Shao, C. M. Burns, X., J. Appl. Polym. Sci., 82(2001)2651

167

POLYETHERSULFONE MEMBRANES MODIFIED BY SURFACTANTS IN ULTRAFILTRATION AND MICELLAR ENHANCED

ULTRAFILTRATION PROCESSES

Gryzelda POŹNIAK , Ryszard POŹNIAK, Adam SOKOŁOWSKI, Marek BRYJAK

Wrocław University of Technology, Faculty of Chemistry WybrzeŜe Wyspiańskiego 27, 50-370 Wrocław, Poland

gryzelda.pozniak@pwr.wroc.pl

INTRODUCTION

Membrane separation processes being more environmental friendly than conventional separation techniques are receiving considerable interest in biotechnology and metallurgical industry. This well consolidated technology is very interesting because of low operative costs, conceptual simplicity, modularity, optimal quality of treated wastewater. Among membrane processes ultrafiltration has deserved some special interest. However wider application of ultrafiltration has been hindered so far due to the detrimental effect of fouling, i.e. an irreversible process caused by solute sorption. In biotechnology, ultrafiltration membranes are commonly used for concentration and purification of protein solutions. Very often protein molecules block membrane pores that result in a decline of membrane flux. Most thermo-resistant polymers have adequate chemical and biological stability suitable for membrane formations but their strongly hydrophobic character accelerates sorption of proteins on the membrane surface. Polyethersulfone (PES) popular membrane material belong to such polymers. There are several methods for the protect membrane from fouling: physical modification by surfactants [1,2] and introduction of ionic groups to the membrane materials by chemical [3-5] or plasma treatment [6,7]. Porous membranes with a fixed charge on the surface prove to be very useful in ultrafiltration of charge-bearing solutes [8-10].

Ultrafiltration (UF) has proved to be an efficient way to remove from water high molar substances (polymers, proteins) - particles of a size ranging from 2 to 100 nm and M larger than 500 Da. As a consequence, the pore size of UF membranes is too large to reject small molecules, like metal ions. The metallurgical industry, especially the electroplating and metal finishing sectors generates huge volumes of water containing heavy metal ions such as Cd2+. Micellar enhanced ultrafiltration (MEUF) is a surfactant-based separation process that has been used to remove heavy metal ions from dilute streams [11,12]. In this process, an anionic surfactant at a concentration higher than its critical micelle concentration (cmc) is added to the aqueous stream containing the dissolved solutes. The negatively charged micelles force the cations to be bond to the micelle interface.

168

Micelles (size above 10 nm) with the bonding cations are then separated by UF using membrane of suitable porosity, capable of retaining micelles.

SDS ADDITIVE

RETENTATE

PERMEATE

ULTRAFILTRATION MEMBRANE

MOLECULE SDS MICELLE

SOLUBILIZED METAL CATIONS

SOLUBILIZED METAL CATIONS

METAL CATIONS

Fig.1. Schematic of metal cations separation by MEUF

To enhance selectivity in MEUF, it has developed ligand-modified micellar

enhanced ultrafiltration (LM-MEUF) [13]. This method involves addition of an amphiphilic ligand and a surfactant to the contaminated solution under conditions where most of the sufractant is presence as micelles. The ligand has a high degree of solubilization in the micelles and to a tendency to selectively complex the target metal ion.

The goal of this paper is to show the effect of surfactant use for two membrane processes: ultrafiltration of protein and micellar enhanced ultrafiltration removal of Cd(II) ion. Two UF membranes were subjected to surfactant modification: polyethersulfone and sulfonated polyethersulfone.

EXPERIMENTAL

Sulfonation of polyethersulfone and preparation of membranes

The polyethersulfone (PES ULTRASONE E-2020P from BASF) was sulfonated using a mixture of chlorosulfonic acid (CSA) and 1,2-dichloroethane (at room temperature, 90 min). The initial molar ratio of CSA to PES was 3:1.

O S

O

OSO3

n

Sulfonated polyethersulfone (SPES)

Porous asymmetric membranes were formed by phase-inversion method

from: 13.5%-wt. solution of PES, mixture of 15%-wt. PES plus 10 %-wt.

169

polyvinylpirrolidone (PVP 10 kDa) and 30%-wt. solution of sulfonated PSU in N,N-dimethylformamid (DMF). Water was coagulation medium.

Transport properties

The Amicon 8200 dead-end UF cell with membrane surface area of 19.6 cm2 was used. The transmembrane pressure was set at 0.1 MPa.

Ultrafiltration of bovine serum albumin

The membranes formed from mixture of PES and PVP were immersed in sodium dodecylsulfate, SDS (16.2 mmol/dm3) or monoether dodecylpentaoxyethylene glycol, EDPEG (0.12 mmol/dm3) solutions (24 hr). Additionally, the process was carried out in two cycles: membrane was kept in SDS solution for 24 hr and then immersed in EDPEG solution for 5 min.

OSO3 Na

Sodium dodecylsulfate (SDS), cmc = 8.1 mmol/dm3

O(C2H4O)5H

Monoether dodecylpentaoxyethylene glycol (EDPEG), cmc = 0.06 mmol/dm3

The performance of surfactant modified membranes was determined with

buffer of pH 8 and 0.1 M buffered solution of bovine serum albumin (BSA). The concentration of protein in permeate was detected at 280 nm (Specord M-40, Carl Zeiss). From the flux values before and after protein filtration the transport parameters: fouling index (FI), reduction of the flux in filtration (RF) and solute rejection (R) were calculated according to our procedure [10]:

FI = 1 – (Jf /Jo) (1) RF = 1 – (Jp /Jo) (2) R = 1 – (cp /co) (3)

where: Jo - flux of buffer through the freshly mounted membrane, Jp - flux of

buffered BSA through the same membrane, Jf – flux of buffer through the membrane after BSA filtration, cp and co concentration of protein in the permeate and in the feed solution, respectively.

Micellar enhanced ultrafiltration of cadmium

Mixtures of SDS (8.1, 40.5 and 81 mmol/dm3) and CdCl2 (1 mmol/dm3) and mixtures of SDS (4.0, 8.1 and 40.5 mmol/dm3) and CdCl2 (1 mmol/dm3) with ligand 8-hydroxiquinoline, 8-HQ (4 mmol/dm3) were filtrated through PES and SPES

170

membranes. The concentrations of metal ions and SDS in permeate were determined by atomic adsorption spectrophotometer (AAnalyst 100, Perkin-Elmer).

RESULTS

The two systems were used to obtain more permeable membranes from

polyethersulfone (PES): (i) adsorption of surfactants: anionic (sodium dodecyl sulfate) and nonionic (monoether dodecyl-pentaoxyethylene glycol), (ii) chemical introduction of sulfonate groups to the polymeric chains.

Three kinds of membranes were used in this study. Two of them we selected according to their similarities in physical structure, they differ in chemical composition only (PES and SPES, Table 1).

Membranes from PES+PVP system were used to hydrophilization by adsorption of surfactants. They have the great average pore diameter, because after physical modification of surfactants ultrafiltration of bovine serum albumin has been realized.

Table 1. Characteristics of the used membranes

Membrane Flux of water

dm3/m2h

Total

porosity

%

Avarage pore

diameter

Nm

–SO3 groups

concentration

mmol/g

PES + PVP 410 79 59 0.00

PES 53 72 13 0.00

SPES 76 79 18 0.79

Ultrafiltration of BSA

Effect of membrane hydrophilization by surfactants was monitored by evaluation of permeate fluxes and resistance of membrane to fouled by bovine serum albumin. Hydrophilization was carried out according to different protocols: in one cycle by immersion in surfactant solution and in two cycles by subsequent sorption of two surfactants - anionic and nonionic. It is well known that BSA molecules have negative charge at pH=8. Negative charge appeared also on membrane modified with SDS, hence some repulsive effect should be expected. With nonionic surfactant (EDPEG), improvement in filtration indices are ascribed to the thick hydrophilic layer on the membrane surface which keeps the protein molecules over the pore entrance. [14]. Results of BSA ultrafiltration are show in Table 2.

171

Table 2. Filtration indices of surfactant modified membranes PES+PVP

Surfactant FI

%

RF

%

R

%

SDS 21 33 95

EDPEG 15 28 96

SDS/EDPEG 6 15 98

NONE 58 77 91

In comparison with unmodified PES membrane, the modified species show

a significant improvement of their performances in protein filtration. Fouling (FI) is less intensive and reduction of the flux in BSA filtration (RF) shows lower values. It is worthy to note that the best results were obtained for BSA filtration through membrane modified with consecutive sorption of SDS and EDPEG. That phenomenon can be rationalized by combined effect of nonionic surfactant that protects membrane against deposition of BSA while the anionic surfactant reduces the fouling potential of BSA molecules which penetrate the first surfactant layer [14]. It is important to note here that presence of surfactants on membrane do not affect the separation properties of membranes; values of BSA rejection (R) are similar.

Micellar enhanced ultrafiltration of cadmium

The second reason of surfactants use in filtration processes is the phenomenon of enhanced removal of harmful species conducted by micelle that are too large to penetrate membrane pores. To check the effect of surfactant that is needed to remove Cd2+ ions, the MEUF processes were investigated. The results are shown in Tables 3 and 4.

Table 3. Cadmium flux and rejection in MEUF process

PES

membrane

SPES

membrane

SDS concentration

mmol/dm3 J

dm3/m2h

R

%

J

m3/m2h

R

%

8.1 46 73 68 85

40.5 37 80 51 97

81.0 23 85 27 99

172

Table 4. Cadmium flux and rejection in LM-MEUF process

PES

membrane

SPES

membrane

SDS concentration

mmol/dm3

J

dm3/m2h

R

%

J

dm3/m2h

R

%

4.0 55 78 76 88

8.1 47 86 71 98

40.5 41 91 55 99

The highest rejection coefficient was observed for SDS concentration

equal to 81 mmol/dm3 MEUF and 40.5 mmol/dm3 in LM-MEUF process. As usually, sulfonated polyethersulfone membrane worked more effectively that its off-charge analogue [3, 5]. There is one more conclusion that can be withdrawn from the presented data. Removal of divalent cations by means of MEUF and LM-MEUF hybrid systems is based on electrostatic binding of ions to oppositely charged micelles [11]. According After addition of 8-HQ to SDS solution, the cmc is lower then without 8-HQ [15]. The evaluation of cmc for SDS in the solution under investigations was 0.9 mmol/dm3 what means about 10 times less that cmc for SDS in distilled water. Additionally, mixed micelles of ligand and surfactant with bound metal ions are more rigid and therefore rejection of micelles is higher what is favorable for cadmium recovery too [15].

CONCLUSION

Hydrophilization of PES membranes by surfactant sorption improves membrane properties in filtration of BSA. Polyethersulfone and sulfonated polyethersulfone membranes can be used for separation of heavy metal ions by means of MEUF. However, charged membranes are more effective that its off-charge analogue. The best cadmium ions separations were observed for LM-MEUF process.

ACKNOWLEDGEMENTS

Financial support of this work was provided by the Polish Committee for Scientific Research - grant no. 3 T09B 047 28.

REFERENCES

1. D. Doulia, V. Gekas, G. Trägårdh, J. Membr. Sci., 69(1992)251 2. A-S. Jönsson, B. Jönsson, J. Membr. Sci., 56(1991)49

173

3. G. Poźniak, M. Bryjak, W. Trochimczuk, Angew. Makromol. Chem., 233(1995)23

4. B. Turkiewicz, M. Rucka, G. Poźniak, E. Zboińska, Enzyme Microbial Technol., 39(2006)527

5. R. Guan, H. Zou, D. Lu, C. Gong, Y. Liu, Eur. Polym. J., 41(2005)1554 6. M.Bryjak, G. Poźniak, I. Gancarz , W. Tylus, Desalination, 163(2004)231 7. M. Bryjak, I. Gancarz, G. Poźniak, Chem. Papers 54(2000)496 8. G. Poźniak, I. Gancarz, M. Bryjak, W. Tylus, Desalination, 146(2002)293 9. M. Bryjak, I. Gancarz, G. Poźniak, W. Tylus, Eur. Polym. J., 38(2002)717 10. G. Poźniak, I. Gancarz, W. Tylus, Desalination, 198(2006)215 11. J. F. Scamehorn, D. C. Sherril, D. A. El-Sayed, H. Uchiyama, Sep. Sci. Technol.,

29(1994)809 12. G. Poźniak, M. Bryjak, R. Poźniak, Surfactants and dispersed systems in theory

and practice, Ed. K.A. Wilk, Wrocław (2005)571 13. B. R. Fillipi, J. F. Scamehorn, S. D. Christian, R. W. Taylor, Sep. Sci. Technol.,

32(1997)2401 14. D. V. Chen, A. G. Fane, C. J. D. Fell, J. Membr. Sci., 67(1992)249 15. A. Paulenovà, P. Rajec, M. Ježikovà, J. Kučera, J. Radioanal. Nuclear Chem.,

208(1996)145

174

CHROMIUM (III) MEDIATED TRANSPORT IN THE BULK LIQUID MEMBRANE SYSTEMS

Katarzyna ROTUSKA

Chemical Metallurgy Division, Department of Chemistry, Wrocław University of

Technology, WybrzeŜe Wyspiańskiego 23, 50-370 Wrocław

ABSTRACT

Tanning processes consumes only 70% of chromium of the tanning bath, residual chromium is released into wastewaters. The possibility of recover and recycle the residual metal is a main purpose at technological improvements.

A good affinity of DNNSA towards chromium(III) ions is documented in literature and is the best among all other carriers tested for Cr(III) mediated transport in liquid membrane systems [1-5].

The studies of chromium(III) removal from the model tanning solutions were performed in the bulk liquid membrane system. Effects of concentration dinonylnaphtalenesulphonic acid as a carrier of Cr(III) in a membrane phase, as well as chloride and sulphate ions concentration in feed phase on effectiveness of chromium(III) permeation were studied.

EXPERIMENTAL

The initial feed phase was chromium(III) chloride solution with Cr(III)

concentration of 0.058 mol/dm3 and pH 4. The pH was adjusted with 0.1M NaOH. In a following experiments the composition of feed solution was changed by addition of potassium chloride or sodium sulphate. 4M H2SO4 solution was as a receiving phase.

The bulk liquid membrane was composed from a mixture of kerosene and o-xylene and dinonylnaphtalenesulphonic acid as a carrier of Cr(III) ions. All experiments were done in a two compartment vessel with a barrier. Feed and stripping phases were mixed at 50 r.p.m., liquid membrane wasn’t mixed. All experiments were performed at 25ºC. Different experimental conditions were studied to establish their effect on transport rate of Cr(III). The concentration of DNNSA in a membrane was equal to 20, 25, 30 and 50% (v/v) respectively. The concentration of chromium ions was determined in feed and stripping phase spectrophotometrically with Spekol-205 at wavelength 595 nm. The concentration of Cr(III) in membrane was calculated from the mass balance:

)( OZpM cccc +−= where cM denotes Cr(III) concentration in membrane phase while cp, cz and c0 stand

175

for initial and actual concentration of Cr(III) in the feed and stripping solution, respectively.

RESULTS AND DISCUSSION

The obtained results showed that the composition of organic phase is significant for the transport rate of Cr(III). It should be noticed that the higher carrier concentration in membrane phase results in the faster transport of Cr(III). But there is an optimal concentration of DNNSA above which the effectiveness of Cr(III) transport decreases considerably (Fig.1).

This is probably due to the formation of DNNSA-Cr(III) complexes which increase the viscosity of the membrane. For further studies the concentration 25 %(v/v) of DNNSA in the membrane was chosen as optimal.

Fig.1. Chromium(III) flux vs. DNNSA concentration in membrane phase

The effect of chloride ions concentration (0.28 and 0.42 mol/dm3, respectively) and sulphate ions concentration (0.10 and 0.21 mol/dm3, respectively) on chromium(III) permeation was also studied.

The obtained results (Fig.2) prove that the increasing concentration of chloride and sulphate ions decrease the yield of extraction and reextraction, respectively.

However, the negative effect of sulphate ions on Cr(III) permeation is lower than that observed for chloride ions. Probably this is affected by a different stability of corresponding Cr(III) complexes formed in the feed solution.

Moreover, the rate of reaction was slow down, when the feed solution contained both chloride and sulphate ions, but the observed trend was similar to that established for sulphate ions only.

176

Fig.2. Cr(III) concentration changes vs. time. Initial concentration of Cr(III) in feed phase - 0.058 M, pH = 4; - in the absence of salts; - 0.42M KCl, - 0.21M Na2SO4; - 0.42 M KCl + 0.21 M Na2SO4. Indexes z, m and o refer to donor, membrane and receive phases, respectively

CONCLUSIONS

1. An increase of carrier concentration to a certain value in membrane phase increases the permeation of Cr(III), but after exceeding this concentration the decrease of process effectiveness is observed. It is due to the increase of membrane viscosity and low diffusion ability of its components. 2. An increase of chloride and sulphate ions concentrations in feed phase decrease the yield of Cr(III) extraction and reextraction. The negative effect of sulphate ions on Cr(III) permeation is lower than that of chloride ions.

REFERENCES

1. R. Molinari, E. Drioli, G. Pantano, Sep. Sci. Technol., 12,13(1989)1015 2. K. Rotuska, P. Religa, Z. Szwast, Transport Cr(III) przez membranę ciekłą,

Materiały konferencyjne XXV Sympozjum im. B. Krzysztofika AQUA 2005, Płock 2005

3. R. Gawroński, P. Religa, Przenoszenie jonów chromu (III) w układach z membraną ciekłą, Monografie Komitetu InŜynierii Środowiska PAN, 22(2004) 295

4. R. Gawroński, P. Religa, InŜ. Aparat. Chem., 4s(2003)80 5. K. Prochaska, Adv. Coll, Interfac. Sci., 95(2002)51

Time, h0 5 10 15 20 25 30

C m

ol/d

mM

,3

0.03

0.02

0.01

0

Time, h0 5 10 15 20 25 30

Co,

mo

l/dm

3

0.01

0

0.02

Time, h0 5 10 15 20 25 30

Cz,

mol

/dm

3

0

0.02

0.04

0.06

177

THE AIR SEPARATION THROUGH POLYMER AND “MAGNETIC” MEMBRANES

Aleksandra RYBAK, Zbigniew J. GRZYWNA

Department of Physical Chemistry and Technology of Polymers,

Section of Physics and Applied Mathematics, Faculty of Chemistry, Silesian University of Technology,

Strzody 9, 44-100 Gliwice, Poland

The air separation is a very important problem in industry as well as in everyday life. There are known several methods for air separation or oxygen enrichment [1]. In this paper we focus on the membrane separation techniques [2-11].

In case of the air, which components and their diffusion coefficients differ very little, the separation is an extremely difficult problem. To enhance the process we use an external magnetic field which influences the oxygen flux, due to its paramagnetic features [12,13].

We have used three types of membranes: plane (polyethylene, polystyrene, ethylcellulose), conductive (polyaniline, polyaniline with polystyrene) and magnetic (magnetic powder like neodymium or ferrite dispersed in ethylcellulose). All these membranes were made by casting from the polymer solution and then examined in our experimental setup. This setup was furnished with a gas chromatograph what let us to measure concentration of oxygen and nitrogen in permeate. To influence the oxygen flux even more we have used modified diffusive chamber, furnished with internal magnetic plates. For the data analysis we have used D3-D5 system, which gives the possibility to calculate five different diffusion coefficients, permeation and sorption coefficients.

We have shown that using a magnetic field is a very promising and attractive way of the air separation.

REFERENCES 1. B. Freeman, Y. Yampolskii, I. Pinnau, Materials Science of Membranes for Gas

and Vapor Separation, Wiley and Sons, 2006 2. M. Bodzek, Pol. J. Environm. Stud., 9(2000)1 3. W. J. Koros, R. Mahajan, J. Membr. Sci., 181(2001)141 4. R. W. Baker, Ind. Engin. Chem. Res., 41(2002)1393 5. R. V. S. Uppaluri, P. Linke, A. C. Kokossis, Ind. Engin. Chem. Res., 43(2004)

4305 6. M.-R. Huang, X.-G. Li, X.-L. Ji, W. Qiu, L.-X. Gu, J. Appl. Polym. Sci.,

77(2000)2396

178

7. B. C. Bhide, S. A. Stern, J. Membr. Sci., 62(1991)13 8. S. G. Kimura, W. R. Browall, J. Membr. Sci., 29(1986)69 9. Z. J. Grzywna, Dyfuzyjny transport masy w membranach heterogenicznych

regularnych, Dział Wydawnictw Politechniki Śląskiej, Gliwice 1984 10. A. Stolarczyk, M. Łapkowski, M. Nowicki, Polimery, 45(2000)814 11. M. Łapkowski, A. Stolarczyk, Synth. Met., 121(2001)1385 12. K. Kitazawa, Y. Ikezoe, H. Uetake, N. Hirota, Phys. B, 294(2001)709 13. T. Tagawa, H. Ozoe, K. Inoue, M. Ito, K. Sassa, S. Asai, Chem. Engin. Sci.,

56(2001)4217

179

ANION-EXCHANGE IN GEMINAL DICATIONIC IMIDAZOLIUM IO NIC LIQUIDS

Andrzej SKRZYPCZAK*, Jan BŁASZCZAK* Jadwiga ZABIELSKA-

MATEJUK**

*Poznań University of Technology, Institute of Chemical Technology and Engineering, pl. M. Skłodowskiej-Curie 2, 60-965 Poznań, Poland

**Institute of Wood Technology, ul. Winiarska 1, 60-654 Poznań, Poland; e-mail: Andrzej.Skrzypczak@put.poznan.pl

Since the introduction of the first low melting ionic liquids we observe

growing interest in their potential as replacement for the conventional organic solvents. These environmentally friendly solvents have been studied as solvents used reaction media, as solvents in separation processes, as solvents in catalysis, in electrochemistry and others. Among the many unique properties of ionic liquids is an extraordinary degree of tunability, with relatively minor changes in the structure of the constituent cation or anion, frequently leading to major changes in physicochemical properties. Such tunability is of potential utility in the aplication of ionic liquids in various separations processes. Anion-exchange in geminal dicationic imidazolium ionic liquids is one of the the ways providing us to compounds of unique properties.

1,6-Di(chloromethoxy)hexane was obtained by reaction of chloromethylation, bulbbing gaseous hydrogen chloride through mixture of 1,6-hexanediol and paraformaldehyde, purifying by distillation under reduced pressure. Obtained ether was used as quaternization agent for 1-alkyl-imidazoles. In the result of the quaternization reaction three (2,9-dioksadecamethylene)-1,10-bis(1-alkylimidazolium chlorides) were obtained. Next step of synthesis of geminal ionic was anion exchange reaction: replacement of chloride anion by tetrafluoroborate, nitrate, formate, acetate or propionate ones. As the result of carried out reactions, were prepared three hydrophobic ionic liquids (tetrafluoroborates) and twelve hydrophilic ionic liquids (nitrates, formates, acetates, propionates). The ion-exchange reaction proceeded smoothly, with the efficiency usually exceeding 90%. These salts are insoluble in hexane or diethyl ether, but are soluble in acetone, chloroform, DMF, THF, ethyl acetate, toluene, and low-molecular-weight alcohols. They are stable in air, in contact with water, and in commonly used organic solvents.

ACKNOWLEDGEMENT

This investigation received financial support from the Polish Committee of Scientific Research 3 T08E 089 29.

180

ANION-EXCHANGE OF DICATIONIC QUATERNARY AMMONIUM CHLORIDES

Andrzej SKRZYPCZAK*, Jan BŁASZCZAK* Jadwiga ZABIELSKA-

MATEJUK**.

*Poznań University of Technology, Institute of Chemical Technology and Engineering, pl. M. Skłodowskiej-Curie 2, 60-965 Poznań, Poland

**Institute of Wood Technology, ul. Winiarska 1, 60-654 Poznań, Poland e-mail: Andrzej.Skrzypczak@put.poznan.pl

The great interest of ionic liquids composed bulky ions, is their negligible

vapour pressure, low meting point, good thermal stability which make them liquid over a large temerature range. They are also non-flamable and easy to recycle. Room temperature ionic liquids are considered now as potential substitutes to many traditional organic solvents in reaction and separation systems. Among the many unique properties of ionic liquids is an extraordinary degree of tunability, with relatively minor changes in the structure of the constituent cation or anion, frequently leading to major changes in physicochemical properties. Such tunability is of potential utility in the aplication of ionic liquids in various separations processes. Anion-exchange in dicationic quaternary ammonium salts results new class of geminal ionic liquids possesing unique properties.

1,6-Di(chloromethoxy)hexane was obtained by reaction of chloromethylation, bulbbing gaseous hydrogen chloride through mixture of 1,6-hexanediol and paraformaldehyde, purifying by distillation under reduced pressure. Obtained ether was used as quaternization agent for N,N-dimethyloctylamine, N,N-dimethyldecylamine and N,N-dimethyldodecylamine. In the result of the quaternization reaction seven (2,9-dioksadecamethylene)-1,10-bis(alkyldimethylammonium chlorides) were obtained. Next step of synthesis of geminal ionic was anion exchange reaction: replacement of chloride anion by tetrafluoroborate, nitrate, formate, acetate or propionate ones. As the result of carried out reactions, were prepared three hydrophobic ionic liquids (tetrafluoroborates) and twelve hydrophilic ionic liquids (nitrates, formates, acetates, propionates). The ion-exchange reaction proceeded smoothly, with the efficiency usually exceeding 95%. These salts are insoluble in hexane or diethyl ether, but are soluble in acetone, chloroform, DMF, THF, ethyl acetate, toluene, and low-molecular-weight alcohols. They are stable in air, in contact with water, and in commonly used organic solvents.

ACKNOWLEDGEMENT

This investigation received financial support from the Polish Committee of Scientific Research 3 T08E 089 29.

181

INFLUENCE OF IONIC LIQUIDS ANION–EXCHANGE ON MENSCHUTKIN REACTION RATE CONSTANT

Andrzej SKRZYPCZAK

Poznań University of Technology, Institute of Chemical Technology and

Engineering, pl. M. Skłodowskiej-Curie 2, 60-965 Poznań, Poland; e-mail: Andrzej.Skrzypczak@put.poznan.pl

Room temperature ionic liquids have been proposed as solvents for green

processing because of their unique physical properties, such as nonvolalility and nonflammability. The physical properties of ionic liquids can be tuned by varying the structures of their ions in order to optimalize the solvent properties for specific applications. Ionic liquids affect reaction rates and selectivity. To understand the effects of ionic liquids on chemical reactions, the rate constants for several elementary reactions in ionic liquids have been studied and compared to those in other solvents. In a number of cases the rate constants in ionic liquids were lower than those in water and polar organic solvents either because of the high viscosity of ionic liquids, which limits the diffusion rate, or because of an apparent lower polarity.

Rate constants for the Mienschutkin reaction of benzyl bromide with 1,2-dimethylimidazole have been measured in eight synthesised ionic liquids using spectrophotometric detection. It was found that the wide selection of pure ionic liquids do not absorb light to any significant extent at wavelenghts above 260 nm and that the disappearance of benzyl bromide can be followed at 270-280 nm with only minimal interference from absorption of 1,2-dimethylimidazole. Eight rate constants were determined in eight ionic liquids. The ionic liquids behave in this reaction like the polar aprotic solvents and variations within the anion-exchange in ionic liquids indicate significant effect of solvent anion [(CF3SO2)2N]-< PF6

-<BF4-

on measured rate constant. Such determination of anionic influence on rate constant will permit design of ionic liquids by proper choice of anion structure for enhancement of the rates of specific reactions.

ACKNOWLEDGEMENT This investigation received financial support from the Polish Committee of Scientific Research 3 T09B 080 28.

182

NEW APPROACH TO OPTIMIZATION OF THE Q-CASCADES

Georgy A. SULABERIDZE, Valentine D. BORISEVICH and Yuriy V. LITVIN

Moscow Engineering Physics Institute (State University), 31 Kashirskoe Shosse,

Moscow 115409, Russia

INTRODUCTION

The cascades for separation of multicomponent mixtures consisting of

separation stages (elements) with the overall enrichment coefficients ijε (i and j are the numbers of components) much less than unit play the important role in the practice of mixture separation. The design calculation of such separation cascades for given values of the product flow and concentrations of a target component in the product and waste flows lies in searching the total number of separation stages in a cascade N, the number of stages in enriching SP and depleting SW sections of a cascade, a flow distribution over cascade stages L(S) as well as defining the values of the product or waste flows. At the same time the set of found parameters has to correspond to the optimal value of this or that a criterion of efficiency. In the theory of mixture separation this problem is used to solve by means of the concept the model cascade of continuous profile (MCCP) that permits to get the expressions for the cascade parameters analytically. This gives a way to make a further calculation of a real cascade by approximation of the found model cascade by squared or squared-off cascades and subsequent optimization of their parameters. The common approach to calculation of MCCP for the case of multicomponent mixtures is described in the papers [1,2]. Its gist of the matter is in substitution of concentrations

)(SCi of the mixture under separation to some characteristic function )(Siϕ , that allows to reduce the mass transfer equation in a cascade to the well-known Volterra integral equations with the singular kernel [3]:

The simple and suitable for further mathematical calculation MCCP may be obtained when the characteristic function )(Siϕ will be assigned as a set of exponents:

))(exp()( SQS ii =ϕ ,

where Qi are constants banded by the condition

[ ] )exp()(

)(exp)()(

2)(

11 0

SSL

LCdttSt

SL

PCS ij

m

j

FFi

m

j

S

iji

Pj

i εεϕϕ ∑∑ ∫==

−=−+ (1)

(2)

183

ijji QQ ε=− , (3)

This implies that when the value of ijε is known only one of the values of Qi can be chosen arbitrary. The model cascades corresponding to the conditions (2) were named as the Q-cascades. Assignment of the characteristic function in the form (2) allows to obtain the analytical expressions for the distributions of flows and concentrations over a cascade length, to define values of the product and waste flows and represent the concentrations in the product PiC , and waste WiC , flows through the concentrations in the feed flow point FiC , . Examination of the obtained analytical formulae demonstrates that by means of the Q-cascades one can operate of the process to concentrate various component of separating mixture choosing corresponding sign of the Qi constants. The possibility exists in the long ( 1,1 >>>> WP SS ) Q-cascades to separate mixture components into two groups. In the first group the component concentrations go up and in the second one they go down.

PROBLEM STATEMENT

As is known, for the molecular kinetic separation methods (thermodiffusion,

mass-diffusion, gas diffusion) the overall enrichment coefficient ijε may be rewritten in the form as follows [4]:

)(0 ijij MM −ε=ε , (4) where ij MM , are the mass numbers of the ith and jth components, respectively, and 0ε is the enrichment coefficient for unit mass difference. This allows presenting the Q constant for each of mi ,...,1= component as

)(0 ii MMQ −= ε , (5) where M is a parameter, defining uniquely the Qi constants for all mixture components.

The present paper is devoted to the new approach, in which M plays a role of a new optimization parameter for the Q-cascades. The parameter M has the following physical interpretation: the components of the separating mixture with the mass number lighter than the parameter M ( MM i < ) will be enriching in the direction to the “light” end of a cascade, while the components with the mass numbers MM i > will be concentrating to the “heavy” one. Also, it is assumed that together with the real components can be taken into account the virtual ones with the vanishing initial concentrations which mass numbers are changing constantly in the limits of mMMM <<1 , where m is a number of separating mixture components. Beside, if the parameter ( ) 2ji MMM += , it means that the no-mixing condition for the flows at the inlet of each cascade stage takes place for the components with

184

the i and j numbers [5]. The possibilities and advantages of the new approach to optimize MCCP will be demonstrated below.

RESULTS AND DISCUSSION

Here we demonstrate the optimization of the Q-cascade for separation of the

krypton isotope mixture with the natural abundance in the feed flow by the M parameter introduced above using the total interstage flow as the efficiency criterion.

Fig.1. Dependences of the relative total flow versus a value of the M parameter

for various concentrations of the target component in the product flow.

The dependences of the relative total flow in the Q-cascade PL 2/20εΣ

versus the value of the M parameter for four different concentrations of the target lightest component 78Kr in the product flow

%201 =PC , %301 =PC , %501 =PC , %901 =PC ) and the fixed %12.01 =WС concentration of the same components in the waste flow is shown in Fig.1. In calculation the enrichment coefficient for unit mass difference was taken equal to

=0ε 0.01. The dependences obtained show that for the given concentrations of the target components in the product and waste flows there exists the optimum value of M* providing the minimum of the total flow in the cascade. So in the first case, when

%201 =PC , the minimum of the total flow happens to the value of the parameter M close to 81* =M what corresponds to the no-mixing condition for the components with the mass numbers 78 and 84. Increase of the target component concentration in the product flow leads to the decrease of the *M value longing in the limit to the value of 792/)8078(2)(* 21 =+=+= MMM .

185

The similar regularities have been also discovered in the case of enrichment of intermediate components in the separating mixture.

CONCLUSIONS

1. The new approach to optimize the Q-cascades using the special parameter M is developed. 2. It was demonstrated that for the given concentrations of a target component in the product and waste flows there exists the optimum value of the parameter *M for which the total flow in a cascade is minimal one.

REFERENCES

1. R. Ya. Kucherov, V. P. Minenko, Atomic Energy, 19(4)(1965)360 (in Russian) 2. N. A. Kolokoltsev, V. P. Minenko, B. I. Nikolaev et al., Ibid, 29(6)(1970)425 (in

Russian) 3. G. A. Korn and T. M. Korn, Mathematical Handbook for Scientists and

Engineers, М. Science 1973, pp.832 (in Russian) 4. G. A. Sulaberidze, V. D. Borisevich, Sep. Sci. Technol., 36(8-9)(2001)1769 5. G. A. Sulaberidze, Q. Xie, V. D. Borisevich, Ars Separatoria Acta, 4(2006)67

186

EFFECT OF ORGANIC SOLVENT ON THE PERTRACTION OF Zn( II) AND Cu(II) CATIONS IN BLM CONTAINING D2EHPA

AS A CARRIER

Piotr SZCZEPAŃSKI

Nicolaus Copernicus University, Faculty of Chemistry, Gagarina Str. 7, 87-100 Toruń, Poland; e-mail: piotrs@chem.uni.torun.pl

Liquid membrane processes with organophosphorus compounds such as

di(2-ethylhexyl) phosphoric acid (D2EHPA) are frequently applied for recovery and separation of Zn2+ and Cu2+ cations [1-4]. The separation of cations by pertraction in liquid membranes results from the differences in diffusivity and affinity of a carrier towards cations present in a treated solution. Concentration of the feed and stripping solution, carrier concentration and the type of organic solvent are the most important factors influencing the pertraction process. The nature and composition of the organic phase also have a strong influence upon the interfacial activity of D2EHPA [5]. The aim of this study was to investigate the effect of a liquid membrane solvent on transport and separation of Zn2+ and Cu2+ cations in the bulk liquid membrane (BLM) with D2EHPA as the carrier.

The experiments were performed with a simple beaker-in-beaker type pertractor at 25ºC. The solution of Zn2+ and Cu2+ nitrates (125 cm3 0.05 M) was used as the feed phase. The sulfuric acid solution (25 cm3 0.1 M) was used as the stripping phase. The membrane contacting area was 16.45 cm2 (f/LM interface) and 5.8 cm2 (LM/s interface). 0.1 M D2EHPA (25 cm3) in hexane, heptane, octane, nonane, decane and dodecane were used as the liquid membrane. The solutions were agitated with a glass stirrer (LM) at 375 rpm and magnetic stirrer (feed and stripping solution) at 150 rpm. The experiments were carried out 3 times in order to evaluate the standard error of respective fluxes. Under these experimental conditions, D2EHPA transports Zn2+ over Cu2+ and its selectivity increases with an increase in the molecular weight of alkane. Typical experimental results corresponding with the system containing octane as D2EHPA solvent are presented in Fig.1.

The effect of the organic solvent on the pertraction of Zn2+ and Cu2+ cations is presented in Fig.2. Some physicochemical properties and the topological indices (calculated from the chemical structure of the solvent) were applied to describe the solvent structure – BLM properties (flux) relationship by chemometric methods. It was concluded that a simple linear model is sufficient to describe the fluxes as a function of physicochemical properties (density, viscosity, refractive index) and topological indices (descriptors) of an organic solvent.

187

Fig.1. Experimental curves of Zn2+ and Cu2+ transport in BLM with 0.1 M D2EHPA dissolved in octane: (●) feed solution, (■) stripping solution

membrane organic solvent

Fig.2. Dependence of Zn2+ and Cu2+ fluxes on the number of C atoms in liquid

REFERENCES

1. T.-Ch. Huang, R.-S. Juang, J. Membr. Sci., 31(1987)209 2. D. He, X. Luo, Ch. Yang, M. Ma, Y. Wan, Desalination, 194(2006)40 3. R.-S. Juang, H.-L. Huang, J. Membr. Sci., 208(2002)31 4. R.-S. Juang, H.-L. Huang, J. Membr. Sci., 213(2003)125 5. J. Szymanowski, G. Cote, I. Blondet, C. Bouvier, D. Bauer, J. L. Sabot,

Hydrometallurgy, 44(1997)163

Time [h]

0 10 20 30 40 50

Con

cent

ratio

n of

Cu

2+

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.0000

0.0001

0.0002

0.0003

0.0004

0.0005

0.0006

0.0007

Time [h]

0 10 20 30 40 50

Con

cent

ratio

n of

Zn

2+

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Number of C atoms

5 6 7 8 9 10 11 12 13

Flu

x of

Zn

2+

2.0e-9

4.0e-9

6.0e-9

8.0e-9

1.0e-8

1.2e-8

Number of C atoms

5 6 7 8 9 10 11 12 13

Flu

x of

Cu

2+

5.0e-12

1.0e-11

1.5e-11

2.0e-11

2.5e-11

3.0e-11

3.5e-11

188

STUDIES ON THE PHYSICAL CHEMISTRY OF (4-CHLORO-2-METHYLPHENOXY)ACETIC ACID

IN TWO-PHASE SYSTEM: N-ALIPHATIC ALCOHOL -WATER

Jolanta SZLACHTA, Jan KALEMBKIEWICZ

Department of Inorganic and Analytical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańców Warszawy Ave., 35-959

Rzeszów, Poland

Phenoxyacetic acid derivatives, mainly 2,4-D, MCPA, 4-CPA, show biological activity and are a selective translocated herbicides classified as auxin. They are commonly used to control broadleaf weeds in crop production. They are biologically active components of about 60 pesticides, which are used in Poland [1-5]. Due to the fact that they are widely applied in agriculture and have a great influence on the natural environment, a detailed description of their equilibria in aqueous solutions and two-phase systems is very important. Therefore, in this paper an analysis of (4-chloro-2-methylphenoxy)acetic acid (abbreviated as MCPA) equilibria in these systems was carried out and the fundamental physicochemical parameters such as dissociation (pKa), distribution (KD) and dimerization (Kdim) constants as well as distribution coefficients (DHR) were determined. Moreover, an influence of selected parameters of the systems on equilibria was analysed (pH, polarity of organic solvent) with regard to creation and coexistence of different acid forms in the examined systems.

As a consequence of the slight solubility of the MCPA in water, potentiometric titrations in methanol-water were performed and the Yasuda-Shedlovsky procedure was used to determine the acid dissociation constant in water [6-9].

Next, the potentiometric titrations of MCPA in the two-phase systems organic solvent - water were carried out using n-aliphatic alcohols by series C5 - C10 as organic phase. Based on the conducted distribution investigations and acid equilibria model in two-phase system, values of DHR, KD and Kdim were obtained for each examined system [10-12]. It follows from the experiments that the values of these parameters depend on the organic solvent polarity. It was noticed the distribution coefficient DHR and distribution constant KD decreased with the increase in the number of carbon atoms in the aliphatic chain of the alcohol, according to the following series (pH 1≈ ): pentan-1-ol > hexsan-1-ol > heptan-1-ol > octan-1-ol > nonan-1-ol > decan-1-ol. In case of the dimerization constants Kdim an inverse dependence was observed. Having analyzed the obtained results, it was also found that the distribution coefficients depend significantly on pH of the aqueous phase and the highest values are adopted for pH < 2.5, i.e. in the range where undissociated form HRw of acid exists and dominates in aqueous phase. The increase of the pH of aqueous phase is accompanied by a decrease in DHR. The reason for this

189

is a gradual transfer of the undissociated acid form HRw in dissociated R-w, which according to the Born equation, is not subject to extraction to organic phase.

Based on the determined values of Ka, KD and Kdim as well as the molar balance of the acid in the studied systems, the concentration of the various forms (HRo, HRw, (HR)2,o, Rw

-) of MCPA in both phases was calculated as a function of pH of the aqueous phase. It was concluded that percentage of these forms strongly depend on solvent polarity and pH of aqueous phase.

The results presented here show that the polarity of organic solvent and pH of aqueous phase have a great impact on extraction conditions of MCPA and its equilibria in the two-phase systems organic solvent – water.

ACKNOWLEDGMENT

This work was financed from Ministry of Science and Higher Education funds (Grant No. N205 007 31/0079).

REFERENCES 1. J. M. Wells, L. Z. Yu, J. Chromatogr. A, 885(2000)237 2. T. Cserhǎti, E. Forgǎcs, J. Chromatogr. B, 717(1998)157 3. V. Andreu, Y. Picó, Trends Anal. Chem., 23(10)(2004)10 4. Raport of European Commmission, Health and Consumer Protection Directorate

- General, 2001 [On-Line]. Available web: http://europa.eu.int/comm/food/plant/protection/evaluation/existactive/

5. Polish Monitor 03.38.562 6. A. Avdeef, J. E. Comer, S. J. Thomson, Anal. Chem., 65(1993)42 7. A. Albert, E. P. Serjeant, The Determination of Ionization Constant, third ed.,

Chapman and Hall, London,1984, pp. 48-53 8. K. Takács-Novák, K. J. Box, A. Avdeef, Int. J. Pharm., 151(1997)235 9. A. Avdeef, K. J. Box, J. E. A. Comer, M. Gilges, M. Hadley, C. Hibbert, W.

Patterson, K. Y. Tam, J. Pharm. Biomed. Anal., 20(1999)631 10. J. Kalembkiewicz, S. Kopacz, Wiad. Chem., 41(1987)437 11. J. Kalembkiewicz, L. Zapała, Polish J. Chem., 75(2001)1797 12. J. Kalembkiewicz, J. Szlachta, J. Solution. Chem. (2007) in press

190

RETENTION BEHAVIOUR OF SELECTED FLAVONOIDS IN RP-HP LC SYSTEMS WITH CHEMICALLY MODIFIED ADSORBENTS

Wojciech ZAPAŁA1), Lidia ZAPAŁA2), Jolanta SZLACHTA2)

1) Department of Chemical and Process Engineering, 2) Department of Inorganic and Analytical Chemistry, Chemical Faculty, Rzeszów University of Technology, Al.

Powstańców Warszawy 6, 35-959 Rzeszów, Poland The retention of a solute in RP – chromatography is a very complex process

which depends on many factors. Therefore, the study of the influence of a mobile phase modifier concentration on the retention in different reversed phase chromatographic systems is very important for understanding the regularities of the retention and mechanisms of substance separation in a chromatography process. Composition changes and the nature of mobile phases enable tuning of the separated analytes’ retention in a wide range of the retention parameters and optimization of the chromatographic process, as well. Optimization of the chromatographic process can be achieved by several different methods, one of them is so-called interpretative strategy. The key role in this strategy is the implementation of adequate retention models that couple the retention of solute with the composition of a mixed mobile phase. The employment of chemically bonded stationary phases composed of partially non – bonded silica matrix and organic ligands bonded to its surface in the everyday chromatography practice leads to the questions of the correct definition of retention model and dominant retention mechanism in such chromatographic systems.

In this work the influence of mobile-phase composition on the retention of selected flavonoids in different reversed-phase HPLC systems with chemically modified adsorbents (including polar and non-polar chemically modified adsorbents) has been studied.

The aim of this study was to compare performance of the five earlier established retention models known from literature: • The adsorption model which assumes the heterogeneity of adsorbent surface

proposed by Zapała [1]:

(1)

• The adsorption – partition model proposed by Kaczmarski et al. [2]:

(2)

ϕ

ϕϕ

⋅+

+⋅+⋅

=

41

3211

p

ppp

k

( ) ( )ϕϕϕ

−⋅+⋅+⋅+=

143

121exp

ppppk

191

• The partition model proposed by Snyder [3]:

• The adsorption model proposed by Nikitas et al. [4,5]:

● The Schoenmakers’ model [6,7]:

The equation constants (pi) were estimated by minimization of a sum of the squared differences between the experimental and theoretical data using the Marquardt method [8]. The accuracy of determination of the model parameters was assessed for the 95% confidence interval of Student’s test. Models (1)–(5) were compared by use of our own experimental results and retention data also taken from the literature [9]. The following statistical criteria were used for the assessment of the tested models accuracy in different HPLC systems: • The sum of squared differences between the experimental and the theoretical

retention data:

• Approximation of the standard deviation:

• The Fisher test:

where: i = 1…N, N - number of experimental points, l - number of estimated model parameters.

The results obtained for different RP-HPLC systems tested in this work demonstrate that the best agreement between the experimental and calculated k values was obtained by the use of new-generation retention models, which assume heterogeneity of adsorbent surface. The results reported here show that heterogeneity of the adsorbent surface may be important in analysis of elution process in liquid chromatography. Consideration of the goodness of fit for the

( )

⋅+

⋅−⋅+−=

ϕ

ϕϕ

21

321ln1exp

p

pppk

322

1ln pppk +⋅+⋅= ϕϕ

ϕ⋅−= 21ln ppk

( )∑ −=i

2theorexp )i(k)i(kSUM

( )

( ) ( )∑

∑ ∑

=

=

−⋅−

−⋅−

=N

itheor

N

i i

ikikN

N

ikiklN

F

1

2exp

1

2

expexp

)()(1

)()(

(3)

(4)

(5)

(6)

lN

SUMSD

−= (7)

(8)

192

experimental data to the examined retention models is in conformity with the adsorption mechanism of retention on all chemically bonded stationary phases for most investigated compounds.

REFERENCES

1. W. Zapała, J. Chromatogr. Sci., 41(6)(2003)289 2. K. Kaczmarski, W. Prus, T. Kowalska, J. Chromatogr. A, 869(2000)57 3. L. R. Snyder, J. W. Dolan, J. R. Gant, J. Chromatogr., 165(1979)3 4. P. Nikitas, A. Pappa-Louisi, P. Agrafiotou, J. Chromatogr. A, 946(2002)9 5. P. Nikitas, A. Pappa-Louisi, J. Chromatogr. A., 971(2002)47 6. P. J. Schoenmakers, H. A. H. Billiet, R. Tijsen, L. De Galan, J. Chromatogr.,

218(1981)261 7. P. J. Schoenmakers, Optimization of Chromatographic Selectivity – A Guide to

Method Development (Journal of Chromatography Library, 35), Elsevier, Amsterdam 1986

8. R. Fletcher, A modified Marquardt sub-routine for nonlinear least-squares, AERE-R6799-Harwell – England 1971

9. Y. D. Kahie, C. Pietrogrande, M. I. Medina Mendez, P. Reschiglian, F. Dondi, Chromatographia, 30(1990)447

193

IONIZATION AND PARTITIONING PROFILES OF 2-METHYLAMINOBENZOIC ACID

Lidia ZAPAŁA1), Jolanta SZLACHTA1), Jan KALEMBKIEWICZ1), Wojciech

ZAPAŁA 2)

1) Department of Inorganic and Analytical Chemistry, 2) Department of Chemical and Process Engineering, Faculty of Chemistry, Rzeszów University of Technology, 6

Powstańców Warszawy Ave., 35-959 Rzeszów, Poland

The physicochemical characterization of anthranilic acid and their derivatives have been conducted for many years. Especially the extraction systems and interfacial equilibria have been studied [1-4]. In this paper the results of the investigations of 2-methylaminobenzoic acid (belongs to the group of amino acid) in the aqueous solution and in two-phase systems are presented.

Fundamental parameters for amino acids in aqueous solution are: isoelectric point pHI, dissociation constant of cationic form Ka1 (H2R

+ HR + H+) and neutral form Ka2 (HR R- + H+). The values of this constants were determined by the potentiometric titration in aqueous solution (KCl, I = 0.1). Based upon the determined values of Ka1 and Ka2 as well as pHI, the coexistence of particular forms of 2-methylaminobenzoic acid in aqueous solutions was analysed.

The pH-partitioning profiles were examined in toluene/buffer, benzene/buffer, chlorobenzene/buffer, dichloromethane/buffer and chloroform/buffer systems. The shape of the four profiles are similar showing the maximum of the pH range 2-5. The obtained bell-shaped curves are characteristic of the partitioning of a zwitterionic compound [4-5]. Depending on the polarity of organic solvent, the values of the partition coefficient D increase in the following order:

Dtoluene < Dbenzene < Dchloroform < Dchlorobenzene < Ddichloromethane

Using a model of singular and multistep equilibrium [6,7] and results of the potentiometric titration in two-phase systems: aromatic solvent (ethylbenzene, p-xylene, toluene, benzene, chlorobenzene, bromobenzene, nitrobenzene, dichloromethane, chloroform, tetrachloride carbon) – aqueous solution (I=0.1, KCl), the partition constants KD and the dimerization constants Kdim were calculated. They depend on the polarity of organic solvent. It has also been found, that the partition constants increase, while the dimerization constants decrease with increasing Hildebrand’s solubility parameter δ. The lowest value of KD was found for tetrachloride carbon, while the highest one was noted for nitrobenzene. At the same time, the highest value of dimerization constant Kd is observed for tetrachloride carbon and the lowest for nitrobenzene.

194

REFERENCES

1. L. Zapała, J. Kalembkiewicz, Annals Polish Chem. Soc., (2003)526 2. L. Zapała, J. Kalembkiewicz, J. Szlachta, Polish J. Chem., 79(2005)1235 3. L. Zapała, J. Kalembkiewicz, Talanta, 69(2006)601 4. L. Zapała, J. Kalembkiewicz, Proceedings of the XIXth International Symposium

on Physico Chemical Methods of the Mixture Separation „Ars Separatoria 2004”, Złoty Potok, 160

5. G. Caron, A. Pagliara, P. Gaillart, P. A. Carrupt, B. Testa, Helv. Chim. Acta, 79(1996)1683

6. J. Kalembkiewicz, L. Zapała, Polish. J. Chem., 75(2001)1797 7. S. Kopach, B. Papciak, J. Kalembkiewicz, Zh. Obshch. Khim., 67(1997)294

195

BOND-GRAPH DESCRIPTION AND SIMULATION OF MEMBRANE PROCESSES. 1. DONNAN DIALYSIS

GraŜyna SZCZEPAŃSKA, Romuald WÓDZKI

Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toruń, Poland

Thermodynamic network analysis (TNA) was applied for modeling and

theoretical description of the Donnan dialysis of univalent cations through a cation-exchange polymer membrane. The method allows studying the respective reaction-diffusion phenomena through the formalism of bond-graph method [1-4]. The network of the local fluxes (D-diffusion, R-reactions) and capacitances {X} (Fig.1) corresponds with a set of coupled differential equations which can be solved numerically (solver: Berkeley Madonna v. 8.0) to describe the evolution of all the concentrations (capacitances) appearing in the DD network in time.

Fig.1. The network of Donnan dialysis with cation exchange membrane separating

(at t=0) the solution of KA salt and HA acid

For model studies, it was assumed that: (i) the membrane is composed of a cation exchange polymer, (ii ) the membrane is placed between feed and stripping aqueous solutions containing salt (KA) and acid (HA), respectively (at t=0), (iii ) the electrolyte uptake (u) and release (r) at the membrane/aqueous solution interface are described by a uni-molecular reaction scheme and Glueckauf isotherm of non-exchange sorption of electrolytes into inhomogeneous polyelectrolyte gel, (iv) permeation of free electrolytes through the internal solution of the membrane phase occurs according to the percolation theory for diffusion in heterogeneous media, (v) inter-diffusion of K+ and H+ cations (DK/H), as mediated by functional groups (MK,

0 0 R(u) FD 0 0

{KA} (f) (u)

{KA} (m) (n)

{KA} (m) (u)

{KA} (f)

0

{KA} (f) (1)

D(KA) 0

{KA} (m) (1)

R(r) SD 0

{KA} (s) (r) {KA} (m)

(r)

{KA} (s)

0

{KA} (s) (1)

1

0

0

1

1

0

0

R(ex)

0 0

1 1

0

R(ex)

R(u) FD 0 0

1

0

{MH} (m) (u)

{MK} (m) (u)

{HA} (f) (u)

{HA} (m) (u)

{MH} (m) (n)

{MK} (m) (n)

{HA} (m) (n)

{HA} (f)

0

{HA} (f) (1)

R(ex)

1

0

R(ex)

0

1

0

{MH} (m) (1)

{MK} (m) (1)

{HA} (m) (1)

D(KH)

D(KH)

D(HA)

{MH} (m) (r)

{MK} (m) (r)

R(r) SD 0

{HA} (m) (r)

{HA} (s)

0

{HA} (s) (1)

{HA} (s) (r)

196

MH), and diffusion of free electrolytes (DKA, DHA) is locally coupled by cation exchange reactions (Rex), (vi) the external solutions are intensively agitated to limit respective diffusion phenomena to the interfacial diffusion layers represented by simple linear diffusion network FD and SD in Fig.1, respectively.

The up-hill transport of K+ was calculated and discussed on the basis of physicochemical characteristics of Nafion-117 membrane. Selected results of theoretical calculations were experimentally verified.

REFERENCES

1. G. Oster, A. Perelson, A. Katchalsky, Nature, 234(1971)393 2. G. Oster, A. Perelson, A. Katchalsky, Quart. Rev. Biophys., 6(1973)1 3. A. R. Peacocke, An Introduction to the Physical Chemistry of Biological

Organization, Oxford 1989, pp.73-107 4. H. Paytner, Analysis and Design of Engineering Systems, MIT, Cambrigde

Mass., 1961

197

BOND-GRAPH DESCRIPTION AND SIMULATION OF MEMBRANE PROCESSES. 2. MEBRANE EXTRACTION

GraŜyna SZCZEPAŃSKA, Romuald WÓDZKI

Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toruń, Poland

Membrane extraction usually occurs in a system with a porous polymer

membrane separating an aqueous (feed) and an organic (extractant) liquid phase [1,2]. A similar system with a polymer cation-exchange membrane can be considered as a hybrid membrane extraction process (HME). In fact, when an extractant is capable of exchanging cations, the HME system is equivalent to the Donnan dialysis system in which the stripping aqueous solution is replaced by an organic one. Consequently, at the feed solution/membrane interface, and inside the membrane, the process occurs as described in Part 1 with a similar network description (DD module in Fig.2). However, the model needs an additional modification in respect to the operation of the extractant at the membrane/organic phase interface. For this purpose the presence of a special reaction layer (rk) in the membrane was assumed.

Fig.2. The network of hybrid membrane extraction with D2EHPA as an extractant of univalent cations

To carry out the model studies of the HME system, typical materials of the

properties widely reported in literature were selected, i.e. the Nafion-127 cation-exchange polymer membranes, and a liquid organic phase composed of di(2-ethylhehyl) phosphoric acid (CH) dissolved in kerosene. All the possible reactions

{CKCH} (o)

{MH} (rk)

{MK} (rk)

0

1

0

0

R(ex)

1

0

1

0

0

R(ex)

DKA

DKH

DKH

DHA

DD

0 0

1 1

0

R(ex)

R(u) FD 0 0

R(u)

{KA} (f)

0

FD 0 0

1

{HA} (f)

0

{H +A-} (rk)

0

{K +A-} (rk)

0

0 D(dim)

R7

TD(2)

D(mono) 0

D(2)

R3

0

1 1

R5 1 0

{KACH} (rk)

{CKCH} (rk)

{CK} (rk)

{(CH)2} (rk)

R4 1

1

1

R1

1

1 1 R2

{C -H+} (rk)

0

0

D(1)

D(3)

R6

{CH} (rk)

0

0

R7

TD(2)

0 D(CH)

D(CH)2

0 D(CKCH)

0 D(KACH)

0 D(CK)

{KA} (f) (u)

{KA} (f) (1)

{KA} (m) (n)

{MH} (m) (u)

{MK} (m) (u)

{KA} (m) (u)

{HA} (f) (1)

{HA} (f) (u) {HA} (m)

(u)

{MH} (m) (n)

{MK} (m) (n)

{HA} (m) (n) {CH} (o)

(1) {CH} (o) (b)

{(CH)2}(o) (1) {(CH)2}

(o) (b)

{CK} (o) (0)

{CK} (o) (1)

{KACH} (o) (1)

{KACH} (o) (b)

{CKCH} (o) (b)

(1)

198

of this reagent with the components of the membrane (counterions, electrolytes in its internal solution) were then described in the framework of thermodynamic network analysis, i.e:, ion exchange between dimerized CH and MK (R1), ion exchange between CH and MK (R2), ion exchange between dimerized CH and KA (R3), ion exchange between CH and KA (R4), complexation of KA by CH (R5), dissociation of CH (R6). The dimerization of CH in the organic phase is represented in the network by reaction (R7). The products of R1-R5 reactions are extracted to the organic phase as CKCH, CK, and KA�p(CH)2

species. This step is described as interfacial permeation from rk layer to the diffusion layer of the organic phase (o,1). The transport of all the extractant forms through the interfacial diffusion layer into the bulk solution (agitated) is represented by respective linear networks: -D(X)- . The numerical calculations were carried out to recognize the mechanism of HME functioning and its effect forms on the organic phase composition.

REFERENCES

1. W. S. W. Ho, K. K. Sirkar, Membrane Handbook, Van Nostrand Reinhold, New

York 1992, pp. 725-763 2. R. Kertesz, M. Simo, S. Schlosser, J. Membrane Sci., 257(2005)37

199

POLYMER MICROSPHERES WITH N-METHYL-D-GLUCAMINE FOR BORON REMOVAL FROM AQUEOUS SOLUTIONS.

Joanna WOLSKA*, Marek BRYJAK*, Nalan KABAY**

*Division of Polymer and Carbonaceous Materials, Wrocław University of

Technology, WybrzeŜe Wyspiańskiego 27, 50-370 Wroclaw, Poland

** Ege University, Chemical Engineering Department, 35100 Izmir, Turkey

Boron concentration in surface water in Europe varies from less than 10 µg

B/L to more than 1000 µg B/L. If it is present in larger amount it becomes toxic [1]. For that reason WHO recommends 0.3 µg B/L as the critical value for tap water. There are several methods used for boron removal from aqueous solutions. Among them, the ion-exchange processes in which N-glucamine-type chelating resins have been used are the most efficient [2-4]. This paper presents the process of preparation of polymeric microspheres with N-methyl-D-glucamine ligands that can be used in the Submerged Membrane – Ion Exchange Hybrid Process to remove boron.

Four types of polymeric microspheres with different amount of monomers were prepared. Their compositions are described in Table 1. In the first step, oil in water emulsions were prepared by means of membrane emulsification. The organic phase containing vinylbenzyl chloride (VBC,) styrene (St), divinylbenzene (DVB) and dissolved benzoyl peroxide (BPO), was pressed through the metallic membrane with 5 µm pores to the continuous water phase of 1% poly(vinyl alcohol) (PVA) and 5% NaCl solution. The flow rate of 1 ml per 1 min was kept throughout all studies. After emulsification the o/w emulsion was poured into the round-bottomed flask and the suspension polymerization was carried out. Then the dispersion was cooled down and obtained microspheres were washed with large amount of hot and cold water followed by rinse in acetone. The microspheres were filtered, dried and extracted with toluene in Soxhlet apparatus. After drying the average diameter of microspheres, polydispersity and chloride were determined. The average diameters of the obtained microspheres were about 5 times larger than the diameters of applied membrane.

Ion – exchange resins that contained N-methyl-D-glucamine groups, were prepared in 3 ways: i) by boiling spheres for 2 hr in 1,4-dioxane (BP), ii) by microwave modification with dimethyl sulfoxide (DMSO) or dimethyl formamide (DMF), and iii) by modification in the room temperature (24 h) in DMSO or DMF. After each modification the resin was washed with acetone, aqueous acetone (1:1), water, and then conditioned with 1 M HCl, 1M NaOH and water. After drying the chloride, nitrogen, water regain and acid capacities were determined. Characteristics of each resins are described in the Table 1. The data above allowed us to chose the yellow highlighted microsphere as the best for boron removal process.

200

Table 1. Characteristics of microspheres.

Resin

composition

Modification

method

Cl content

before

modification,

mmol/g

Cl content

after

modification,

mmol/g

N content,

mmol/g

Acid

capacity,

mmol/g

Water

regain,

g/g

St:VBC 1:1

DVB 6 %

BPO 0.6%

BP Microwave

DMF

DMSO

24 h

DMSO

DMF

2.51

0.72

0.66

0.49

0

0.50

1.73

0.98

1.42

1.46

1.04

0.92

0.29

0.35

0.74

1.38

0.90

0.75

0.99

0.71

0.57

St:VBC 7:3

DVB 6%

BPO 0.6%

BP M ICROWAV

E

DMF

DMSO

24 h

DMSO

DMF

1.28

0

1.13

0.48

0.19

0.72

0.83

0.46

0.64

0.90

0.55

1.18

0.15

0.35

0.66

0.76

0.55

0.40

0.43

0.49

0.35

St:VBC 3:2

DVB 6%

BPO 0.6%

BP

M ICROWAV

E DMF

DMSO

24 h DMSO

DMF

2.12

0

1.5

0.55

0

0.60

1.32

0.34

0.83

0.78

0.77

1.61

0.52

0.31

0.90

1.48

0.51

0.29

0.42

0.49

0.32

St:VBC 4:1

DVB 6 %

BPO 0.6 %

BP

Microwave DMF

DMSO

24 h DMSO

DMF

0.95

0

0.19

0.29

0.25

0.85

0.82

0.31

0.66

0.53

0.42

1.11

0.21

0.45

0.75

0.33

0.16

0.25

0.37

0.17

BP – modification of spheres in boiling solvent, Microwave – microwave modification, 24h –

modification in the room temperature.

The sorption of boron was studied by Adsorption Membrane Filtration Process. A set up of the hybrid process is shown in Figure 1. Two polypropylene microfiltration membranes, with an internal lumen of 1.3 mm and pore diameter of 0.4 micrometer, form the submerge module. The total surface of the membrane was 24 cm2. As shown in the figure, 250 cm3 boron solution is kept in the suspension

201

loop containing various amounts of boron sensitive microspheres. The equivalent volume of fresh feed, that replaces the permeate volume, is pumped to the suspension loop from the siphoned reservoir 2. In the separation process two cross-flows are applied: fresh boron solution from the reservoir 2 is passed to the sorption chamber at the rate equivalent to the permeate flux, and fresh suspension of boron selective resins (ST1), with concentration of 0.5 or 1.0 g/L, is pumped to the sorption chamber at the same rate as that for removal of boron selective resins saturated suspension (ST2). To keep the suspension circulating it was pumped at the constant rate of 10 mL/min (pump 1). The module was kept 30 cm below the reservoir 2 that generated the driving force for the microfiltration process.

Fig.1. Schematic set-up of the evaluated Adsorption Membrane Filtration Process

The results of boron removal from first stage seawater RO (SWRO) permeate:

Fig.2. Boron removal by AMF hybrid. Concentration of resin 1.0g/L, volume replacement rate – 250 min

Membrane module

ST1 ST2

Feed reservoir 2

Permeate

Pump 1

Pump 2 Pump 3

Suspension loop

0

0,5

1

1,5

2

2,5

0 2 4 6 8 10 12 14 16 18 20 22 24 26

time [h]

B c

once

ntra

tion

[ppm

]

202

Fig.3. Boron removal by AMF hybrid. Concentration of resin 0.5g/L, volume replacement rate – 250 min

CONCLUSIONS

Membrane emulsification procedure gives fine microspheres of VBC-St-DVB matrix with the diameter of 25-30 µm. The best way of sphere to attach N-methyl-D-glucamine ligand is to keep the sphere in boiling reactants for 2 hr. The obtained microspheres are excellent coupling agent in the Adsorption Membrane Filtration Hybrid Process. It is estimated that to remove the traces amount of boron from SWRO first stage permeate and to adjust it to WHO mandatory limit one should apply 0.5 g/L of resin suspended in the feed.

REFERENCES

1. A. J. Wyness, R. H. Parkman, C. Neal, Sci. Total Environ., 314-316(2003)255 2. M. O. Simonnat, C. Castel, M. Nicolai, C. Rosin, M. Sadin, H. Jauffret, Water

Res., 34(2000)35 3. M. Badruk, N. Kabay, M. Demircioglu, H. Mordogon, U. Ipekoglu, Sep. Sci.

Technol., 34(13)(1999)2553 4. N. Kabay, I. Yilmaz, S. Yamac, M. Yuksel, U. Yuksel, N. Yidirim, O. Aydogdu,

T. Iwanaga, K. Hirowatari, Desalination, 167(2004)427 The studies were supported by Polish Ministry of Scientific Research and Information Technology under Grant 3 T09B 081 29.

0

0,5

1

1,5

2

2,5

0 5 10 15 20 25 30

time [h]

B c

once

ntra

tion

[ppm

]

203

SORPTION PROPERTIES OF TITANUM(IV) AND ZIRCONIUM(IV ) MONOHYDROGENPHOSPHATES(V) AND THEIR MODIFIED

DERIVATIVES TOWARDS DIAMMINE COMPLEX OF GOLD(I)

Barbara WOŹNIAK, Wiesław APOSTOLUK and Jerzy WÓDKA

Hydrometallurgy Group, Division of Chemical Metallurgy, Wrocław University of Technology, WybrzeŜe Wyspiańskiego 27, 50-370 Wrocław, Poland

INTRODUCTION

The layered α-M(HPO4)2·H2O (α-MP, M = Ti(IV), Zr(IV) I Sn(IV)) exhibit properties of inorganic cation exchangers [1]. The sorption capacities of such materials could be increased by means of intercalation with organic compounds (e.g. alcohols and amines). The intercalation of layered compounds results in the increase of interlamellar separation [2]. The sorption of different cations e.g. alkaline metal cations, transition metal cations (Cu2+, Ni2+, Co2+) on the pure and modified layered compounds was studied from aqueous solutions [3-5]. Unfortunately, there was not enough information about a sorption of metal complexes into such inorganic ion exchangers. Data related to metal ammine complexes is limited to sorption of ruthenium(II) and ruthenium(III) complexes on α-SnP as well as to sorption of platinum(II) and cobalt(II) complexes on α-ZrP [6-9], respectively. Since then nobody has studied the sorption Au(NH3)2

+ on such layered compounds. The main goal of present work is sorption of gold(I) ammine complexes on

pure and modified α-ZrP and α-TiP.

EXPERIMENTAL

Crystalline Zr(IV) and Ti(IV) phosphates were prepared by a slow decomposition of zirconium and titanium fluoride complexes in the presence of phosphoric acid [10,11]. These compounds were modified by n-butylamine. Pure and modified α-TiP and α-ZrP were characterized by powder X-Ray diffraction (XRD), termogravimetric (TG) analysis, elemental analysis and FTIR spectroscopy. BET surface areas of synthesized and modified samples were also determined. Pure and modified Zr(IV) and Ti(IV) phosphates were then used for sorption of gold(I) diammine complex from ammonia solutions in the presence of ammonium sulphate. The sorption of Au(NH3)2

+ on these exchangers was studied of varying temperature, concentrations of ammonia, ammonium sulphate and copper ammine complexes, respectively.

204

RESULTS AND DISCUSSION

It was found that the sorption capacities of modified α-MP (M = Ti, Zr) towards gold ammine complexes are higher than those of pure exchangers. The sorption of diammine Au(I) complexes increases with increasing temperature. The activation energies calculated for pure and modified α-ZrP and α-TiP from the Arrhenius equation amount to 28.2kJ/mol, 83.9kJ/mol, 33.9kJ/mol and 44.2 kJ/mol, respectively which proves that α-ZrP is a better exchanger than α-TiP.

Further experiments were conducted at 80ºC. The best results of sorption of diammine Au(I) complex were achieved using ammonium buffer (0.285M NH3·H2O + 0.0034M (NH4)2SO4)) containing ca. 4 ppm of Au(I). Under these conditions sorption capacities of Au(I) for pure and modified α-ZrP and α-TiP were equal to 0.36mg/g; 0.80mg/g; 0.18mg/g; 0.29mg/g, respectively. It was also found that the negative effect of concentration of ammonia on the sorption of gold ammine complexes in modified α-ZrP and α-TiP is not as strong as this of concentration of ammonium ions. For instance, capacities of modified α-ZrP and α-TiP with respect to Au(I) from the buffer containing 1.71M NH3·H2O, 0.0034M (NH4)2SO4 and ca. 4ppm Au(I) are equal to 0.57mg/g and 0.26mg/g, respectively.

In contrast to ammonia, the effect of concentration of ammonium ions on sorption of gold(I) ammine complexes on modified α-ZrP and α-TiP is a more significant. This observation was confirmed taking into account the efficiency of Au(I) sorption from the buffer containing 0.285M NH3·H2O and 0.0378M (NH4)2SO4, where the determined capacities of Au(I) on modified α-ZrP and α-TiP were equal 0.20mg/g and 0.14mg/g, respectively.

It was also observed that the rate of Au(I) sorption is strongly reduced in the presence of Cu(II). The sorption experiments were performed with ammonium buffer containing 0.285M NH3·H2O, 0.0034M (NH4)2SO4 and ca. 4ppm of Au(I). Without Cu(II), the loading of modified α-ZrP with Au(I) complexes after 6 h was equal to 0.80 mg/g. In the presence of 0.0047M Cu(II) the loading after 24h was equal to 0.68mg/g. It should be also noted that copper ammine complexes were completely removed from this solution after 2h. In experiments with modified α-TiP, under exactly the same experimental conditions, its capacities towards Au(I) and Cu(II) after 24h were significantly lower and equal to 0.15mg/g and 0.43mg/g, respectively.

CONCLUSIONS

The first original experiments of sorption of ammine gold(I) on pure and modified with (n-butyl amine) Zr(IV) and Ti(IV) phosphates were performed. The obtained results prove that sorption of Au(I) depends on temperature and on composition of the feed ammonium buffer solution. The determined activation energies of Au(I) sorption reveal that pure and modified α-ZrP are better exchangers

205

than pure and modified α-TiP. Modified α-ZrP is a very effective towards Cu(II) ammine complexes which strongly depress the sorption of Au(I).

ACKNOWLEDGEMENTS The present work has been sponsored through the grant 3 T09B02129 obtained from Ministry of Science and Higher Education.

REFERENCES

1. Ch. V. Kumar, A. Bhambhani, N. Hnatiuk, Handbook of Layered Materials, Eds:

S. M. Auerbach, K. A. Carrado, P. K. Dutta, M. Dekker, New York 2004, Ch. 7, pp. 313-372

2. G. Alberti, U. Costantino, Intercalation Chemistry, Eds: M. S. Whittingham, A. J. Jacobson, Academic, New York 1982, Ch. 5, pp. 147-180

3. K. M. Parida, B. B. Sahu, D. P. Das, J. Colloid Interface Sci., 270(2004)436 4. V. Y. Kotov, I. A. Stenia, A. B. Yaroslavtsev, Solid State Ionics, 125(1999)55 5. A. I. Bortun, T. A. Budovitskaya, V. V. Strelko, Bull. Chem. Soc. Jpn.,

65(1992)1617 6. M. J. Hudson, A. D. Workman, J. Mater. Chem., 4(1994)1337 7. M. J. Hudson, A. D. Workman, Solvent Extr. Ion Exch., 13(1995)171 8. Y. Hasegawa, G. Yamamine, Bull. Chem. Soc. Jpn., 56(1983)3765 9. Y. Hasegawa, S. Kizaki, H. Amekura, Bull. Chem. Soc. Jpn., 56(1983)734 10. G. Alberti, E. Torracca, J. Inorg. Nucl. Chem., 30(1968)317 11. G. Alberti, U. Costantino, J. Inorg. Nucl. Chem., 41(1979)643

206

SUPPORTED CuO-CERAMIC MEMBRANES FOR CATALYTIC APPLICATIONS

O. V. YAROVAYA , N. N. GAVRILOVA, O. V. ZHILINA, K. I. KIENSKAYA,

V.V. NAZAROV

Mendeleyev University of Chemical Technology of Russia, 9 Miusskaya sq., Moscow, 125047, Russia; e-mail: Y_O_V@yahoo.com

Recently membrane technology has been widely used in many fields and

one of the most interesting is using membranes in catalysis. Catalyst membrane reactor application allows carrying out the reactions at lower temperature and achieving higher selectivity due to the integration of two processes: chemical reaction and membrane separation.

Ceramic membranes with catalytic active layers are of particular interest. Copper oxide (II) itself and different oxide compositions based on CuO demonstrate considerable catalytic activity in many reactions, particularly in oxidation reactions. All well-known methods of copper oxide synthesis are not suitable for obtaining thin CuO layers on the surface of ceramic tubular substrates. Sol-gel technique is the most appropriate for synthesis of thin catalytic active layers because the regulation of the initial sol properties and parameters of the layer coating allows producing membrane with required phase structure and porous characteristics.

Aggregative stable copper oxide hydrosols were obtained by peptization of the copper (II) transient compounds which were synthesized by copper nitrate hydrolysis in sodium hydroxide presence. The results were well-reproducible, the concentration of the dispersed phase was not high (0.2% weight), but enough for thin layer obtaining. The mean hydrodynamic radius of the dispersed phase particles was determined by the dynamic light scattering, it was within the range of 100-120 nm. The estimation of the ζ-potential carried out using the electrophoresis showed that the particles were positively charged, the value of the ζ-potential was rather small and lied within a range from 32 to 38 mV.

In order to improve the aggregative stability hydroxyethylcellulose (HEC) was added to the hydrosols. The experiments conducted proved that the HEC addition allows protecting the particles against the coagulation in the presence of electrolytes. It should be mentioned that HEC acts not only as a stabilizer but it plays a role of the plasticizing agent.

Membranes with thin layers of CuO at the inner and exterior surfaces of supports were obtained by slip-coating and dip-coating. All the supports were pretreated by Na-carboxymetylcellulose in order to produce negative charge at the support surface. Contact time was of 2 minutes, pH value and HEC concentration were of 6.8 and 0.2% wt., respectively. After the coating membranes were dried at the room temperature for 2 hours, and then heated at 135ºC overnight and calcined

207

for 2 hours at 750ºCº. The prepared membranes were characterized by SEM, the cross-section images are presented in Figure 1

Fig.1. SEM images of cross-section of the membranes with 2 layers of CuO: the

membranes with layers prepared from non-stabilized (at the left side) and stabilized CuO hydrosols (at the right side).

All the membranes with CuO layers exhibited the catalytic activity in the

liquid-phase phenol oxidation in the water solutions. Phenol oxidation was carried out at 97-99ºC. The air was used as oxidative agent. Further development of such catalytic active membranes clears the way to the effective purification of waste water from many organic pollutants.

208

SEPARATION OF GAS MIXTURE FLOWING IN NANOSIZE CAPILLARIES

V. M. ZHDANOV1), V. I. ROLDUGHIN2)

1) Moscow Engineering Physics Institute (State University), 115409 Moscow,

Kashirskoe shosse, 31, Russia; phone: (095) 323 93 21, e-mail: vmzhdanov@mail.ru 2)

Institute of Physical Chemistry Russian Academy of Sciences, 119991 Moscow, Leninsky prospect, 31, Russia; phone: (095) 955-46-47,

E-mail: roldugin@phyche.ac.ru

It is well known [1-2], that there is a separation of the components of a gas mixture flowing in fine capillaries under the action of pressure and temperature gradients. The separation arises due to the differences in masses, cross-sections or accommodation coefficients of the molecules of the gas mixture components.

It was shown [3], that the effects related to the surface forces acting in the vicinity of capillary surface should be taken into in consideration of a free molecular gas flow in nanosize capillaries under the action of the temperature gradient. For liquids flowing in ultrafine capillaries these forces determine the velocities of the thermal and diffusion osmosis, the mechanocalorical effect and liquid mixture separation [4]. Theoretical investigations showed that these forces appear naturally in the left-hand side of the Boltzmann kinetic equation for the gas which is non-uniform in temperature. The surface forces significantly effect the flow rate due to the temperature gradient and the termomolecular pressure drop (TPD) between the vessels connected with a package of nanosize capillaries under the steady state [2,3]. The molecules of different kind have different potentials of gas/surface interaction, so the surfaces forces can affect the separation of components of gas mixture flowing in an ultrafine (nanosize) capillary.

In the present communication, the effects of the surface forces on the non-isothermal gas mixture flow in nanosize capillaries are considered. The possibility is shown of the gas mixture separation due to the difference in the potentials of molecule/wall interaction for mixture components in the presence of temperature gradient. The effect of surface forces on the velocities of components flow is determined by the terms of two kinds. In the first kind terms the surface forces manifest themselves in a thermodynamic manner throw the change of the density of molecules in a capillary. The terms of the second kind have the additional kinetic effect discussed earlier in [3]. Since the surface usually attracts the molecules, the kinetic effect increase the gas transfer throw a capillary under the temperature gradient. The explicit expressions for the TPD and separation effects were obtained for both the stationary flow corresponding to the vanishing integral component

209

fluxes. The possibility is discussed of the determination of gas/surface interaction parameters by combined measuring the TPD and separation effects.

ACKNOWLEDGEMENTS

The work was supported by the Russian Foundation for Basic Researches, project no. № 06-01-00374-a.

REFERENCES

1. V. M. Zhdanov, Adv. Colloid Interface Sci., 66(1996)1 2. V. I. Roldughin, V. M. Zhdanov, Kolloidn. Zhurn., 65(5)(2003)652 3. V. I. Roldughin, V. M. Zhdanov, Kolloidn. Zhurn., 64(1)(2002)5 4. N. V. Churaev, Physical Chemistry of Mass Transfer Processes in Porous Media,

Moscow, Khimiya 1990

210

EXTRACTION OF PALLADIUM(II) IONS FROM CHLORIDE SOLUTIONS WITH PHOSPHONIUM IONIC LIQUID CYPHOS ®IL104

Anna CIESZYŃSKA, Magdalena REGEL-ROSOCKA, Maciej WIŚNIEWSKI

Institute of Chemical Technology and Engineering, Poznan University of Technology, Poznan, Poland

Noble metals have a wide range of industrial applications. They are used in electronic, chemical, pharmaceutical and petroleum industries also in instrument and jewelry making. A demand for these metals has increased in recent years, whereas the natural sources are limited. That’s why an interest towards recycling spent materials containing these metals is observed. Extraction is very suitable method for metal recovery from low concentrated sources, including palladium(II). It is the aim of the work to extract Pd(II) from hydrochloric acid solutions of various concentrations and various sodium chloride contents with trihexyl(tetradecyl)phosphonium bis 2,4,4-trimethylpentylphosphinate (Cyphos®IL104, produced by Cytec Industries Inc.).

Extraction has been carried out in a typical way with five millimolar solutions of Cyphos®IL104 in toluene as an organic phase. Aqueous feeds contained 5·10-3 mol dm-3 of palladium(II) chloride in 0.1 - 3 mol dm-3 HCl and 0.1 mol dm-3 HCl in the presence of 0.5 mol dm-3 NaCl. Both phases were mechanically shaken for a period of time between 30 s and 30 min at room temperature and left to stand for phase separation. Palladium(II) concentrations were determined in the initial aqueous solutions and in the aqueous phases after extraction by spectrophotometric method, using potassium iodide as a reagent. Extraction of Pd(II) is very effective. Percentage extraction of Pd(II) from 0.1 M HCl solution amounts to 95% with Cyphos®IL104. Both the increase of HCl concentration and the presence of NaCl have a negative influence on extraction. Extent of extraction from 0.1 M HCl solution in the presence of 0,5 M NaCl is about 80% and from 3 M HCl is lower and amounts to 55% (Fig. 1). Extraction of Pd(II) from aqueous 0.1 M HCl with this phosphonium ionic liquid is rapid and the equilibrium is achieved in 5 minutes (Fig. 2). Cyphos®IL104 is an effective extractant for Pd(II) separation from hydrochloric acid solutions.

211

Pd(II) Pd(II) Pd(II)0

20

40

60

80

100

in 0,1 M HCl + 0,5 M NaClin 3 M HClin 0,1 M HCl

E P

d, %

Fig. 1. Extraction of Pd(II) with Cyphos®IL104 from hydrochloric acid solutions of various concentrations with addition and without sodium chloride.

0 5 10 15 20 25 300

20

40

60

80

100

E P

d, %

Time, min

Fig. 2. Extraction of Pd(II) vs. time of extraction with Cyphos®IL104 from 0.1 M HCl solution.

ACKNOWLEDGEMENT The work was supported by the 32-139/2007-DS grant.

212

REFERENCES

1. I. Szczepańska, A. Borowiak-Resterna, M. Wiśniewski. New pyridienecarboxamides for rapid extraction of palladium from acidic chloride media, Hydrometallurgy, 68(2003)159-170. 2. T.Z. Sadyrbeava. Separation of Palladium(II) and Platinum by bulk liquid membranes during electrodialysis. Separation Science and Technology, 41(2006) 3213-3228.

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THE UPTAKE OF PHENOLS AND ANILINES FROM AQUEOUS SOLUTIONS BY THE POLYMER-DERIVED CARBON MATERIALS

SYLWIA RONKA, ANDRZEJ W. TROCHIMCZUK

FACULTY OF CHEMISTRY, WROCŁAW UNIVERSITY OF TECHNOLOGY,

WYBRZEśE WYSPIAŃSKIEGO 27, 50-370 WROCŁAW, POLAND, E-MAIL : SYLWIA.RONKA@PWR.WROC.PL

Low molecular weight organic compounds are often removed from aqueous

solutions by sorption on porous materials such as activated carbons. Carbon materials can be obtained in pyrolysis processes of nutshells, coals and polymeric resins. The polymer precursors are of special interest in obtaining carbonaceous adsorbents because of their well-defined macromolecular structure. Pore structure of polymer-derived carbons can be, to some extent, controlled by the choice of the precursor material, i.e. the porosity of the polymeric resin, its chemical composition, pore size distribution and the choice of carbonization conditions. All these factors result in carbons with widely varying physicochemical properties. The synthetic carbon materials prepared from polymers are expected to have reproducible characteristics and controlled pore size, as well as good mechanical and thermal properties, so they can be applied as catalyst supports [1] and adsorbents in many separations [2,3]. This work presents the methods of preparation of synthetic spherical carbon materials in order to obtain novel organic compounds adsorbents and their sorptive properties towards phenols and anilines.

A phosphorus-containing carbonaceous adsorbents have been prepared by the carbonization of phosphorylated styrene/divinylbenzene copolymers. Copolymers in spherical forms were prepared by suspension polymerization of monomers and inert diluents. The role of inert diluents is to influence the formation of the porous structure and thus alter capacity of sorbents and selectivity of sorption. These beads were subjected to phosphorylation and the obtained phosphorus–containing groups were hydrolysed to the sodium salt of phosphinic acid. The content of the phosphinic groups, determined by exchanging protons for sodium ions, is 4-5 mmol/g. The polymerization and modification process is illustrated schematically in Figure 1. Thus, prepared polymers were converted to the various metal salts since it is well known that the ionic form of ion-exchange groups in the polymeric precursors have an influence on the resulting carbons porosity. Such dependences were described for sulfonated S/DVB resins [4,5] but to date no references to other cation exchange groups can be found. Therefore, it has been decided to investigate the effect of metal cations such as H+, Cu2+, Co2+ and Fe3+ on the yield and porous structure of carbons prepared by carbonization of phosphorylated S/DVB polymer.

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Fig. 1. Schematic representation of polymer synthesis and modification.

Sorption experiments have been carried out using newly obtained carbon

materials and a series of phenol and aniline derivatives. As sorbates were used 0,5 mM aqueous solutions of nitrophenols (2-, 3-, 4-), chlorophenols (2-, 2,4-, 2,4,6-), aminophenols (2-, 3-, 4-), nitroanilines (2-, 3-, 4-) and chloroanilines (2-, 3-, 4-). The structure of the carbon materials obtained by carbonization of styrene-divinylbenzene copolymers has the major effect upon their sorption ability towards phenols and anilines. The results will be presented during the conference.

REFERENCES

1. B. Li et al., Carbon, 42 (2004) 2669. 2. V. Strelko et al., Carbon, 40 (2002) 95. 3. S. Yenisoy-Karakas et al., Carbon, 42 (2004) 477. 4. J.W. Neely, Carbon, 19 (1980) 27. 5. H. Nakagawa et al., Carbon, 37 (1999) 1455.

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AUTHORS INDEX

A Adamski Z. 104 Alexandratos S.D. 20 Apostoluk W. 44, 104, 160, 203 Arai T. 95 Avram E. 31 B Beker Ü. 69, 72 Błaszczak J. 179, 180 Bogacki M.B. 107 Borisevich V.D. 182 Borrull F. 16 Bryjak J. 112 Bryjak M. 39, 112, 167, 199 C Chagnes A. 14, 58 Chajduk E. 93 Charewicz W. 104 Cieszyńska A. 210 Cote G. 14, 58 Courtaud B. 58 D Danko B. 93, 108 Dinu M.V. 31, 109, 111 Dmitriev D.V. 153 Drabowicz J. 129 Dragan E.S. 31, 109, 111 Dybczyński R.S. 93, 108 F Fontanals N. 16

G Gajda B. 107 Gancarz I. 112 Gavrilova N.N. 206 Gęga J. 76 Girek T. 56 Gładysz-Płaska A. 121, 147 Grzywna Z.J. 177 Gülbayir D.D. 69, 72 H Hoenich N.A. 84 Holdich R.G. 88 Hubicka H. 79 131 Hubicki Z. 79, 98, 131 J Jakubiak A. 124 Jelínek L. 95, 150 Jermakowicz-Bartkowiak D. 106 K Kabay N. 29, 152, 199 Kalembkiewicz J. 188, 193 Kienskaya K.I. 127, 206 Klonowska-Wieszczycka K. 158, 159 Kłos M. 129 Kolarz B.N. 106, 124 Kołodyńska D. 79, 131 Kołtuniewicz A. 32 Kononova S.V. 153 Kotecka A. 104 Kozioł J. 135

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Kozłowska J. 135 Kozłowski C.A. 56, 135 Krivoschepov A.F. 127 Kunicki J. 112 Kurchatov I.M. 137, 139 Kuznetsov Yu.P. 153 L Laguntsov N.I. 137, 139 Lenarcik B. 142, 145 Leszczyńska M. 98 Litvin Y.V. 182 M Majdan M. 121, 147 Malik D.J. 84, 88 Marcé R.M. 16 Marszałkowska B. 52 Maryuk O. 147 Matějka Z. 154 Mištová E. 150, 154 Muchtarova S.E. 127 N Nazarov V.V. 127, 206 Neagu V. 152 O Okay O. 109 Okunev A.Yu. 139 Olszanowski A. 158, 159 Ozmen M.M. 109 P Parashchuk V.V. 153 Parschová H. 150, 154 Parus A. 158, 159 Pilśniak M. 160

Plesca I. 152 Pluciński P. 42 Polkowska-Motrenko H. 93 Poźniak G. 112, 162, 167 Poźniak R. 167 R Radzymińska-Lenarcik E. 142, 145 Regel-Rosocka M. 52, 210 Robak W. 44 Roche I. 84 Roldughin V.I. 208 Ronka S. 213 Rotuska K. 104, 174 Rybak A. 177 S Sadowski P. 147 Samczyński Z. 93, 108 Šebesta F. 150 Semiha M. 72 Sergiel J. 135 Skrzypczak A. 179, 180, 181 Sokołowski A. 167 Sulaberidze G.A. 182 Szczepańska G. 195, 197 Szczepański P. 186 Szlachta J. 188, 190, 193 Ś Śliwa W. 56 T Telecká M. 150 Thiry J. 58 Trochimczuk A.W. 65, 160, 213 Tronin V.N. 137 Trusov L.I. 153

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U Uezu K. 24 Uvarov V.I. 137 V Vlad C.D. 111 Volkov V.V. 153 Volkov A.V. 153 W Walkowiak W. 56, 135 Wei Y. 95 Warwick G.L. 84 Webb C. 84, 88 Williams D.J. 84 Wionczyk B. 60 Wiśniewski M. 52, 210 Wolska J. 199 Woźniak B. 44, 203 Wódka J. 203 Wódzki R. 195, 197 Y Yarovaya O.V. 127, 206 Yuksel M. 152 Z Zabielska-Matejuk J. 179, 180 Zapała L. 190, 193 Zapała W. 193 Zhdanov V.M. 208 Zhilina O.V. 206 Zydorczak B. 158