Chemosphere, Voi.22, Nos.9-10, pp 913-928, 1991 0045-6535/91 $3.00 + 0.00 Printed in Great Britain Pergamon Press plc

MONITORING OF HAZARDOUS WASTE DUMPS

BY THE STUDY OF METALS

AND SOLVENT-SOLUBLE ORGANIC CHEMICALS

ANDRES NAVARRO

Department of Fluid Mechanics. Terrassa School of Engineering (UPC).

Colom, 7. O8222-1errassa, Catalonia, Spain.

ANTONI ROSELL, JOAN VILLANUEVA and JOAN O. GRIMALT*

Department of Environmental Chemistry (C. I .D. -C.S. I ,C. ) .

Jordi Girona, 18. 08034-Barcelona, Catalonia, Spain.

ABSTRACT

The metal and organic composition of twelve soi l core sections col lected at several hazardous waste dumping si tes located in the Besos and Llobregat Basins (Catalonia, N.Eo Spain) have been examined. They have been analyzed by neutron ac t iva t ion , atomic absorption spectrophotometry, gas chromatography and gas chromatography coupled to mass spectrometry. These techniques have allowed the quant i ta t ive measurement of 37 metals and the i den t i f i ca t i on and quant i ta t ion of 135 organic const i tuents.

The analyses have shown that petroleum tar residues and lubr ica t ing o i l s const i tu te the two major types of organic wastes present in these dumps. Organic chemicals from other or ig ins such as phthalates and s i l icones are also abundant. The metal po l lu t ion can be traced from the nickel and chromium content. These two metals are found in highest concentration in sample No. 6 where high concentrations of iron (25%), copper and cobalt are also observed,

In some dumps (Sl and $5) the presence of free sulphur and organosulphur compounds evidences the a c t i v i t y of sulphato-reducing bacteria, which involves a par t ia l mineral izat ion of the disposed organic wastes.

* Author to whom correspondence should be addressed.

913

914

INTRODUCTION

Man has t tad~t lona l ly disposed of wasLes In the most exped|ently and economlcally possible

way. Solid residues have general ly been stored nearby the indust r ia l f a c i l i t i e s where they

have been generated or disposed of in l a n d f i l l s , abandoned quarries, mines or other sites of

marginal commercial value. However, the long-term environmental and human health impact

associated to these ac t i v i t i es have not current ly been considered.

Groundwater po l lu t ion is one of the most outstanding problems resul t ing from incorrect ly

disposed hazardous wastes. Unfortunately, once these aquifers have been pol luted the

restorat ion to a condit ion compatible with health-based standards is extremely d i f f i c u l t

( l ) . Acute cases of aquifer contamination by metals (2), pesticides (3), chlorinated phenols

and phenoxy acids (3) or other mixed hazardous waste leachates (3) have been described in

re la t ion with chemical waste dumping.

Public awareness of the importance and the extent of the problem is recent so that actions

for the enforcement of l a n d f i l l regulations and waste disposal requirements have only

recently been undertakeFb. There has been a worldwide period of indiscriminate and long-term

emplacement of waste chemicals in makeshift dumps which has created serious global

environmental problems (4). In the U.S.A. alone, the estimated annual production of

hazardous wastes amounts 35 mi l l i on metric tons (5) which are d ist r ibuted among 31,000

hazardous waste sites (6).

In Spain, a pr ivate foundation, I ns t i t u t Cerda, has addressed this problem through a

mu l t id isc ip l inary program, ELISA, which is part ic ipated by 17 public and private

ins t i tu t ions covering most of the Spanish autonomous communities. This Program is aimed at

the organization and development of clean up tasks of contaminated sites and addresses a l l

aspects concerned: legal , technical , economic, etc. We describe here the analyt ical work

carried out in some relevant cases as part of the p i l o t demonstration ac t i v i t i es on

i den t i f i ca t i on and character izat ion of pol luted si tes.

The assessment of the source, extent, and environmental impact of hazardous wastes usually

depends on the metal and organic composition of the dumped materials. While metals encompass

a defined number of species the organic compounds const i tute very complex mixtures that

require the use of chromatographic methods for study, such as gas chromatography coupled to

mass spectrometry. In most cases, these studies are only focussed onto the qua l i ta t i ve and

quant i ta t ive descript ion of the v o l a t i l e organic compounds (7-]0) or to those included in

the p r i o r i t y pol lu tant l i s t s ( I I ) . However, non v o l a t i l e or non-pr ior i ty pol lutants are

predominant constituents in most cases. In fact , the understanding of the type of organic

materials and transformation processes occurring in the l a n d f i l l s or in the dumping sites

requires a broad-spectrum of knowledge on the organic species, e i ther natural or

anthropogenic, present in the waste deposits.

We undertake this approach in the present study. Gas chromatography and gas chromatography

915

coupled to mass spectrometry are used for a detailed description of the organic matter

present in several impoundment sites located nearby the Bes6s and the Llobregat Rivers (see

Figure l ) . Two areas situated north and south of Barcelona, respectively, which have

regularly received wastes of diverse origin (e.g. industrial and urban} for more than 20

years. A strong contamination of the surrounding aquifers has been observed in relation to

these act iv i t ies. Metals have also been analyzed by neutron activation and atomic absorption

spectrophotometry.

#)'~'i/~])~{';~ :" LLOBREGAT ~ Paleogene

" S,TES F - - I , . - , , ,

~ ? ; " O 25 50 Km Volcanic Rocks

BESOS RIVER WELL

50 ~ ~ '

' ° , ~ - : . . . . . . -_-_ . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~o. ~ X ;~ X X X X X v . . . . ~, . . . . . . GROUNDWAIERLEVELS

0 ~0 2?o ,370 m CALDES RIVER

WASTE SITES $3

30

FIGURE ]. Sampling areas and ve r t i c a l p r o f i l e s showing the s i t ua t ion of the core sect ions se lec ted for study. Further sampling descr ip t ion is given in Table 1.

916

EXPERIMENTAL

Sa_,,1@jn~ Sampling s i tes were selected in the areas where th ickest waste deposits were expected. Soil

cores (6 m) were obtained by ro ta ry d r i l l i n g . No water nor other d r i l l i n g f l u i d s were used

to prevent external contamination of the samples.

Metal analysis

Total metal content was analyzed by neutron ac t i va t i on in Ac t i va t ion Laborator ies L td . ,

Ontario (Canada).

Acid ex t rac tab le metals were analyzed by d igest ion with (3:1, v/v) HCI:HNO 3. 1 g of so i l was

t reated with 40 ml of th is acid mixture and, a f te r 5 min. s t i r r i n g , the so lu t ion volume was

evaporated to 2 ml. The ex t rac t ion procedure was repeated two more times by successive

add i t ion of 20 and I0 ml HCI:HNO 3 and evaporat ion to a small volume. The suspension was

then f i l t e r e d and the so l id residue r insed with double d i s t i l l e d water. Al l r inses and

ac id ic ext racts were combined and metal concentrat ions were determined by atomic absorpt ion

spectrophotometry fo l l ow ing standard methods (12).

Organic analysis

Soi l sub-samples (30-40 g) were f reeze-dr ied before organic analys is . They were then

sonicated with (2:1) CI2CH2:MeOH as described elsewhere (13). The ex t rac t ion volumes were

vacuum evaporated to almost dryness and redissolved in dichloromethane. They were then

analyzed by gas chromatography (GC) using a Carlo Erba 5300 HRGC instrument equipped wi th a

flame ion i za t i on detector' and a s p l i t l e s s i n j ec to r . A column of 30 m x 0.25 mm i .d . coated

with SE-54 was used ( f i lm thickness 0.25 um). Hydrogen was the ca r r i e r gas (50 cm/s). The

oven temperature was programmed from 30°C to 300°C at 6°C/min holding at 300°C during 20

min. In jec to r and detector temperatures were, respec t i ve ly , 300°C and 330°C. The i n j ec t i on

was in the s p l i t l e s s mode (solvent , dichloromethane; hot needle technique) keeping the s p l i t

valve closed for 35 s.

These ext rac ts were also analyzed by GC-MS using a Hewlett-Packard 5995 instrument coupled

to an HP 300 data system. MS temperatures were: t rans fe r l i ne 300°C, ion source 200°C and

analyzer 230°C. Data were acquired in the e lect ron impact mode (70 eV), scanning from 50 to

650 mass uni ts at Is per decade. GC condi t ions were the same as described above except that

helium was the ca r r i e r gas.

Compound i d e n t i f i c a t i o n was based on the GC-MS data and on co - i n jec t i on with authent ic

standards. Quant i ta t ion was performed from the GC p r o f i l e s using a mixture of n-tetradecane,

n-docosane, n-dot r iacontane, n-hexatr iacontane, anthracene, f luoranthene, chrysene,

benzo(a)pyrene and benzo(ghi)perylene. Samples and standards were repeatedly in jected un t i l

less than 3-5% dispers ion in the area measurements was obtained.

917

RESULTS AND DISCUSSION

Geological and hydrologeological settings.

The Bes6s Basin (lO00 Km 2, see Figure 1) overlies the Catalan Prelitora] Basin. a

disylmnetric tectonic trench f i l l ed by Tertiary deposits and covered by quaternary alluvial

terraces and colluvial glacis. The Quaternary sediments are constituted by layers of clay,

sands and gravels, lhey are irregularly distributed forming thick sequences in the

palaeochannels and thin sediment layers in the threshold areas. The waste discharge sites

$1-4 are located in these Quaternary sequences, in old quarries which have been f i l l ed with

a wide diversity of masonry materials and industrial and urban residues. These sites are

representative examples of the total land (16 Km 2) used for dumping purposes in the Besos

Basin.

Three aquifer systems are present in the Besos River Basin, one is associated to the

Quaternary al luvial deposits, another to the Miocene sequences and another to the igneous

rocks of the Litoral Chain. Only the Quaternary al luvial aquifer is significant. The water

table of the central basin area is generally situated at 3-6 m below surface but high annual

and seasonal oscillations are observed. These aquifers are unconfined although they may

behave as semi-confined due to the presence of superficial layers of clay and s i l t . Their

transmisivity and permeability values range between lOO-I80O m 2/day and 50-200 m/day,

respectively. Efficient porosity is in the order of O,l. The estimated ut i le volume of the

Medium Besos Basin is 50 hm 3. Some correspondence between flood plannes arld piezometric

level increases is observed. About 30 hm3/year are pumped from this aquifer for urban and

industrial water uses.

TABLE I. List of soil samples selected for study.

Sample No.' River B a s i n Waste'site No. Depth (m)

1 Bes6s 1 1.60 2 Bes6s 1 2.70 3 Bes6s 2 2.40

. , . 4, Bes6s 3 0 5 Bes6s 4 0.50' 6 Bes6s 4 1.00 ? Bes6s 4 2.00 B Bes6s 4 2 .40 9 Llobregat 5 3.00

lO Llobregat 5 6.30 11 Llobregat 5 11.5 12 Llobregat 5 12.8

918

The low Llobregat Basin is constituted of quaternary a l l uv ia l deposits which over l ie an

impermeable Palaeozoic substrate. These sediments are constituted of sands and gravels being

d ist r ibuted between r iver terraces. Four terrace levels are observed, the lowest containing

waste site $5. In this area the alluvial aquifer (surface 19 km2) is unconfined having

transmisivity values ranging between 1000 and 40000 m2/day. Efficient porosity is 0.1-0.35

and average thickness 20-40 m. About I00 hm3/year are pumped from this aquifer.

The Llobregat River waste sites encompass ca. 140 ha (500 ha i f the delta is included). $5

dump originated in 1979 when a quarry (surface 11000 m2) was transformed into a discharge

si te of urban and industr ia l residues, lh is resulted in a strong contamination of the

underlying a l l uv ia l aquifer which can be easi ly detected from the high content in ionic

species and heavy metals (e.g. Fe, Mn) in these underground waters.

The samples selected for study in the dumping sites of these two basins are described in

Table I.

Metals

lhe metal composition of the samples collected in SI-5 dumps is reported in Table 2 where

both the results obtained by neutron activation and atomic adsorption spectroscopy are

shown. In addition to the metals indicated in this Table, the neutron activation

measurements have also shown that in these samples silver, iridium and selenium are below

detection l imit , 5 ug/g.

In pr inc ip le , the neutron act ivat ion results indicate tota l metal content whereas the atomic

absorption determinations (obtained af ter strong acid digestion) correspond to the maximum

concentrations that can be eliminated in the form of leachates. The difference between both

types of determinations l i ke l y correspond to the portion of s i l icate-associate metals in the

samples (e.g. in the case of sodium). Thus, the results of iron and zinc indicate that the

tota l concentrations of these metals can be incorporated to the leachates. Some

discrepancies between the results obtained with these two techniques may correspond to

analyt ical errors or sample heterogenity.

Most of the metals reported in Table 2 are in concentration levels of the same order of

magnitude as those usually found in non-polluted soi ls (14). However, except for sample No.

4, the concentrat ions of nickel and chromium are one order of magnitude higher than those

usually encountered in non-contaminated reference soi ls (14). The high concentration of

these two metals indicates that most of the samples are contaminated by industr ia l residues.

In this respect, the i r highest concentrations are found in sample No. 6, which is also

characterized by a very high iron content (25%) as well as copper and cobalt. Samples Nos.

I , 2, I0 and II also exhib i t high nickel and chromium concentrations which, in the case of

samples Nos. ] and 2, are paral le led by copper concentrations higher than those found in

non-polluted soi ls ( l l ) . F ina l ly , samples Nos. 3 and I I exh ib i t an unusual high content in

barium.

919

TABLE 2. Metal content of the so i l core sect ions co l l ec ted at the Besos and L lobregat dumping s i t e s . Sample i d e n t i f i c a t i o n in Table l and Figure I . Concentrat ions in ug/g.

I BESO S LLOBREGAI SITE S1 S2 $3 $4 $5 SAMPLE, No. I 2 3 4 5 6 7 8 9 I0 . I I 12 AI* 17000 14000 19000 18000 13500 6800 16000 22000 As 7 I0 12 7 12 4 20 12 I0 13 9 23 Au 0.008 0.005 0.008 0.005 <0.005 0.005 0.005 <0.005 0.007 <0.005 0.006 <0.005 Ba 460 510 5500 130 610 710 1100 700 650 3300 430 670 Ba* ] O0 70 350 50 120 130 39 19 Ca 70000 50000 400001200000 70000 20000 60000 80000 90000 120000 90000 7000C Ca* 57000 30000 38000 34000 52000 16000 40000 46000 Co 14 13 I0 <5 7 49 I0 12 I I 14 15 13 Cr 460 740 360 27 250 1500 310 280 290 420 870 250 Cr* 40 20 50 18 26 120 21 24 Cs 3 3 3 4 3 2 3 4 3 <2 4 4 Cu* 230 220 40 35 30 150 20 33 Fe 21000 20000 36000 7600 16000 250000 21000 32000 59000 33000 26000 38000 Fe* 30000 22000 44000 l lO00 27000 53000 26000 31000 Hf 3 3 4 <I 3 3 4 3 5 8 5 5 Hg <l <I <I < l <I <I <I < l 45 <I <I <I K* 1800 1700 2650 360( 2100 I000 1700 2000 Mg 13000 8600 l lO00 27000 14000 8900 I I000 12000 Mn 400 350 580 170 450 840 550 360 Mo 13 20 I0 5 <5 36 8 6 19 11 21 5 Na 4800 6900 6000 520 16000 4900 7200 4200 13000 1900 7500 7700 Na* 520 360 720 370 51 O0 330 590 730 Ni 330 550 290 <50 150 690 230 180 230 210 660 150 Pb* 130 I00 50 67 61 17 67 44 Rb 50 71 72 35 77 57 70 82 86 35 86 98 Sb 2.4 2.6 I .6 0.9 1.5 2.6 3.2 0.9 2.3 4.1 2.1 2.8 Sc 3.6 4.9 5.3 2.6 4.3 3.0 5.6 8.5 4.4 5.5 6.2 9.0 Sr* 220 130 170 300 180 53 400 410 Ta <1 <1 <I <1 <I < l <I <I <I 2 < l 2 Th 4.9 6.0 7.3 2.7 6.3 4.2 7.3 8.8 I0 5.9 9.0 lO Fi * 490 440 540 180 450 230 360 330 U 1.9 2.9 2.1 4.4 1.6 1 .I 1.7 2.5 4.0 2.3 2.4 2.7 W 5 5 <4 <4 <4 17 5 <4 <4 8 7 <4 Zn I I 0 140 140 <50 82 53 160 I00 84 210 220 220 Zn* 150 150 210 59 120 l lO 200 140 La 14 19 21 7 18 13 22 26 37 19 27 34 Ce 30 39 40 15 36 24 46 54 83 39 54 68 Nd 9 1 5 15 6 12 9 19 24 30 17 22 29 Sn 2.5 3.3 3.6 1.1 2.8 2.0 3.6 4.3 5.1 3.0 4.6 5.5 !Eu 0.5 0.7 0.7 0.3 0.7 0.4 0.7 0.9 l .0 0.7 0.9 1.2 Tb <0.5 <0.5 0.5 <0.5 <0.5 <0.5 0.6 <0.5 0.9 <0.5 0.6 0.9 ~Yb I .0 I .4 1.5 0.4 1.2 0.90 1.4 1.7 2.1 1.4 1 . l 2.5 kLu 0.16 0.20 0.27 0.07 0.21 0.16 0.25 0.29 0.28 0.21 0.25 0.38

• Metals l abe l l ed w i th an as te r i sk were determined by ac id i c d iges t i on and atomic absorpt ion spectrophotometry. Unlabel led metals were determined by neutron a c t i v a t i o n .

High i ron , n ickel and chromium concentra t ions cons t i t u te one of the most s i g n i f i c a n t

features of the water samples corresponding to the underground aqui fers of SI-5 dumping

s i t es .

920

Organic matter

The organic composition of SI-5 dump samples is i l l u s t r a ted in Figures 2-4 by representation

of the gas chromatographic traces corresponding to the to ta l solvent extracts. The

concentrations corresponding to the 135 organic species iden t i f i ed in these samples are

shown in Table 3. In addit ion to these chromatographically resolved components a l l samples

exh ib i t a complex mixture of unresolved compounds (UCM) that const i tutes the major

solvent-soluble organic const i tuent in terms of absolute concentration. The composition of

these unresolved mixtures is s t i l l under invest igat ion (15) but in some cases the i r or ig in

may be inferred from the d is t r ibu t ions of resolved chemical species present in the samples.

In th is respect, the major chromatographically resolved species of sample No. 4 encompass a

d i s t r i bu t i on of n-alkanes ranging between C13 and C38 with no odd-to-even carbon number

preference, some 17e(H),21B (H)-hopanes, and a mixture of parent po lycyc l ic aromatic

hydrocarbons essent ia l ly composed of naphthalene, acenaphthylene, dibe,zofuran,

phenanthrene, anthracene, f luoranthene, acephenanthrylene, pyrene, benz(a)anthracene,

chrysene/tr iphenylene, benzofluoranthenes and benzopyrenes. This combination of resolved

compounds and the UCM const i tutes a standard mixture of petroleum tar residues.

The same mixture of compounds is also observed in $4 core samples (Nos. 5-8). However, these

samples also contain chemical species or ig inat ing from other pol lu tant sources such as

p las t ic isers (phthalate mixtures, Nos. 5-8), s i l icones (No. 5), chlorobenzenamines and

1-chloro-2-isocyanotobenzene (Nos. 7, 8), 5-chloro-lH-benzothiazole and pp'-DDD (No. 7). In

the case of sample No. 7, the high concentration of 4-chlorobenzenamine and

l-chloro-2-isocyanatobenzene attenuates the chromatographic signal of the UCM (see Figure 3)

but th is sample is one of those containing highest concentration of petroleum tar residues

in core $4 (see Table 3). On the other hand, the strong concentration gradient of

4-chlorobenzenamine and l-chloro-2-isocyanatobenzene between samples 7 and 8 suggests that

the presence of these two compounds in the deeper section may resul t from leakage from upper

soi l levels. In addit ion to these two samples, 4-chlorobenzenamine is also found in sample

4. This compound is used as an intermediate in the synthesis of dyes, pharmaceuticals and

agr icu l tu ra l chemicals. 4-Chlorobenzenamine is h ighly tox ic on inhalat ion, swallowing and

skin adsorption.

In addit ion to these contaminant compounds, higher plant inputs can also be recognized in

these $4 core sections. They are represented by 24-methyl sterols (Nos. 5, 6) and sterones

(No. 6). sandaracopimaric and abiet ic acids (No. 7) and retene, fr iedelan-3-one and

nor-abieta-8,11,13-tr iene (No. 8). Furthermore, sample No. 8 contains a d i s t r i bu t ion of

~-alkanes showing an odd to even carbon number preference in the C27-C33 range which is also

character is t ic of higher plant contr ibut ions. This n-alkane d i s t r i bu t i on can be iden t i f i ed

because i t predominates over other n-alkane mixtures of anthropogenic or ig in . In sam,!es

with higher petroleum tar concentrations (e.g. No. 4) any other possible source of organic

matter associated to t e r res t r i a l vegetation is l i k e l y covered by the hydrocarbon mixture

corresponding to these residues.

921

45 sS

I0. O0 20, O0 30. O0 40. O0 50 • O0 i0. O0 20. O0 30. O0 4 D , O0 50. O0

TIME TIME 32 27

® ' ii® 95 t 131

11

6 13 48 90

p 11

P 1 128~I I~' I / l / l l i l lW' r!J'~ ~

~~ 7 1 17 21 p S S SS 5 9

21 p 5,8 s

, ~ . ~ , . . . . , . . . . . . . . . . . . . . . . . . , . . . . ~ - , , - , , , , , , , , . . . . , , 10 • O0 20 • O0 30 . O0 40 . O0 50 • O0 10 . O0 20 • O0 30 . O0 40 . O0 50 . O0

TIME TIME

FIGURE 2. Gas chromatographic t races showing the composit ion of the solvent so lub le organic compounds found in the so i l core sect ions sampled in SI-3 dumps (Besos Basin) . Sample d e s c r i p t i o n in Table 1 and Figure I . Peak i d e n t i f i c a t i o n in l ab l e 3.

922

J 110 32

® @

S

79 S

1 j,o 32 48 114

150 7 S 27

I ¢ 1

22 _. 72, 73 12 116

11 S S 48

1115 ~ S 1217 P

~ S 7 ,

8

• ' ' I . . . . I . . . . I . . . . 1 . . . . I ~ ' ' ' ] . . . . I . . . . I . . . . I . . . . I ' I 0 . O0 20, O0 30. O0 40. O0 50 • O0 I 0 . 0 0 20 • O0 30. O0 40. O0 50.00

TIME TIME

79 87 11

,,11 zz ~ I,

2:7

12 III

17111

15 63 101 91~ ,L~

' ' ~ . . . . I . . . . I . . . . I . . . . I . . . . I . . . . I . . . . I . . . . f . . . . I ' 3 0 . 0 0 4 0 . 0 0 5 0 , 0 0 1 0 . 0 0 2 0 . 0 0 3 0 , 0 0 4 0 . 0 0 5 0 . 0 0 lo.oo 2o.ooTiME TIME

FIGURE 3. Gas chromatographic traces showing the composition of the solvent soluble organic compounds found in the soil sections of core S-4 (Besos Basin). Sample description in Table I and Figure I. Peak identif ication in Table 3.

923

76 45

® @

895 8 126

" . " ~ . " - . . ~ - . ~ : ' - ~ . . . . . . . . . . . . . . . . . . . . . . . ; - ,_0o , o . ~ o ' ~ , ' . ~ o , . ~ ~ , , . ~ " ~ o ' ~ - . ~ , , ' . ' o ~ , , : i ~ ; o TIME TIME

45

. ® @ 118

_9~ 1128

123

TIME TIME

FIGURE 4. Gas chromatographic traces showing the composition of the solvent soluble organic compounds found in the soil sections of core S-5 (Llobregat Basin). Sample description in Table I. Peak ident i f icat ion in Table 3.

924

TABLE 3. Organic compounds in the soil coresections collected at the Besos and Llobregat dumps Sample ident i f icat ion in Table 1 and Figure I . Concentration in ug/g.

I BESOS LLOBE~ECAT DUMPING SITE: SI S2 $3 $4 $5

No. COMPOUND 1 2 i 3 4 5 6 7 8 9 I0 ii I~ I. 4-ch lorobenzenamine 89 20 0.4 2. l-ch | oro-2- Is ocy anatc.ben2 ene 16 0.4 3. 3-chlorobenzenamJne 1.0 4. I ,] ,2,3,4,4-hexachlorobuta-l,3-diene 60 5. naphthalene 53 6. phthalic anhydride 2.0 1.9 20 0.4 6.8 7. 2-methylnaphthalene 89 0.2 0.4 8, n-tridecane 45 0.2 0.07 9. dlmetbylnaphthalenes 45 0.2 0.3 0.4 0.07

|0. dJ isocyanatomethylbenzenes 13 6.2

II. acenaphthylene 200 0.i 0.2 12. n-tetradecane 0.3 0.6 0.5 0.I 13. dimethylphtha]ate 20

14. 2,6-b | s ( i , l-dime thyle thyl )-4-methylphenol 3.1 ]5. acenapbthene 0.5

]6. dlbenzofuran 71 0.5 0.3

i7. n-pentadecane 80 0.4 0.9 0.5 0.I 18. mel.hyl n-dodeeanoate 2.7

19. fhlorene 48 0,2 0.3 0.2 20, 4-me t hy I benzenesu I fonamide 1.3 21. methy]phthalic anhydrides 0,4 75

22. n-hexadecane 1.2 92 0.4 0.9 0.i 0.09 23. ~exachlorobenzene 50 24. 5-oh I oro-lH-benzothiazole 1.0 25. dibenzothiophene 0.i 0.3

26. _n_-hep tadecane 1.O 98 0.5 0.5 0.06 27. phenanthrene 1.0 390 0.6 1.7 0.5 0.2 28. anthracene 140 0.I 0.3 29. ( l-methylundecyl )-benzene O. 7

30, n-oc tadecane 0.6 Ii0 0.3 0.4 0.05 31. ~-phenyl tcidecane 0.3 32. di ( iso-butyl ) phthalate 1.3 26 0.7 4.5 33. phy tane 53 34. neophytadiene 0.4 0.4 35. phytadiene 0.3 0.i 36. 3-methylphenanthrene 31 0.i 37. 2-methyJ phenanthrene 40 38. 411-cyc I open ta(de f) phenanthrene 42 0.2 39. 4/9-methylphenanthrene 52 40. ] -me thylphenanthrene 62 41. 19-aorabie ta-8,11,13-trlene 0.2

42. n-nonadecane 40 0.I 0.4 0.i 0.04 43. 4,5-dihydropyrene 20 0.1 0. i 0.01 44. dehydrobietln 0.04 45 . su lphu r ( $ 8 ) 16 2 . 4 0 . 2 26 8 . 7 21 46 . _ n - h e x a d e c a n ° i c a c i d 2 , 0 0 . 4 0 . 5 0 . 5 0 . 7 0 . 2 0 . 2 47 , n - e i c o s a n e 1.3

48. fluoranthene 290 0.7 0.8 0.i 0.05 49. acephenanthrylene 190 0.i 0.3

50. pyrene 210 0.6 1.0 0.i 51. n-heneicosane 1.0 130 0.3 52, 3-me t hy I-2- (3,7, ll-trimethyldodecyl )-thiophene 0.25 53, benzo (a) fl uorene 52 54. b e n z o ( b ) f l u o r e n e 50 0 .2 0.1 55. _n-octadecanoic acid 2.0 0.5

56. dehydroabietane 0.03 '.;7. n-docosane 120 58. buty]oc tyIphtha] ate 1.3

59. butylbenzylphthalate 0.4 60. retene 0.i 61. methyl dehydroabletate i.i

62. pp' -DDD 1.0 63. sandaracopimaric acid 0.5 0.4 64. ben zo ( gh i ) fl uoran thene 30 65. methyl fluoranthene/pyrenes 0.3 66. benzo ( b ) naphtho (2, l-d) thiophene 0.4 67. n-trJcosane 1.2 120 0.4 68. abiet-8(14)-en-18-oic acid 1.5 0.5 69. abietic acid 4.0 l.O

925

Table 3. (continued)

I BESOS LLOBREGAT DUMPINO SITE: $ I 82 83 $4 $5

No. COMPOUND i 2 3 4 5 , 6 7 8 9 10 51 12 70 . a b i e t s d i e n o i c a c i d 0 . 3 71 . benzo(c)phenanthrene 25 72 . b e n z ( a ) a n t h r a c e n e 1301 0 . 4 1 . 0 0 . 0 6 73. ehrysene/triphenylene 130 0.6 1.5 0.08 74. n-tetracosane 1.3 0.9 120 0.5 0.04 75. methy[ chrysenes/benzo(a)anthraeene8 6.7 25 0.1 0.3 76. di(2-ethylhexyl)phthalate 25 0.3 0.i 0.03 i00 0.6 2.2 2.1 77. n-pentacosane 110 0.7 0.07 78. n-hexacosane 2.7 120 0.7 0.07 79. benzo(b/j/k)fSuoranthene 200 1.0 1.8 0.2 80. betlzo(a)fluocant|lene 80 0.2 0.5 81. n-heptacosane 2.6 90 0.3 0.9 0.i 82. benzo(e)pyrene 140 0.4 0.9 0.i 83. benzo(a)pycene 145 0.4 0.9 0.I 84. perylene 0.i 0.2 0.03 85. n-octaeosane 2.8 60 0.5 0.08 85. ~/z 252 50 0.2 0 .5 87. n-nonacosane 2.8 110 0.4 1.4 0.2 88. ethylcholestane 0.6 89. 17a(l{),218(}])-30-norhopane 15 9.07 0.2 0.08 1.5 0.I 5.3 90. n-triacontane 2.7 140 0.5 0.08 91. 3-methyl-57s(H),218(H)-30-nochopane 0.5 92. dibenz(a,j)anthracene 0.I 0.8 0.04 93. Indeno(1,2,3-cd)pyre~e 90 0.1 1.0 0.08 94. cholest-5-en-3B-ol 0.21 95. 17~(H),25B(H)-hopane 160 0.02 1.4 5.5 96. dibenz(a,h)anthracene 0.1 0.4 0.01 97. pentaphene 0.05 98. benzo(b)chrysene 0.4 0.05 0.02 99. picene 0.2

100. benzo(ghi)perylene 75 0.2 i.i 0.03 101. n-hentrlacontane 2.3 0.2 15 0,i 1.8 0.3 0.2 102. anthanthrene i0 0.1 103. 38-thlocholestane 3.2 104. 24-methylcholest-22-en-3B-ol 0,4 105. 24-methylcholest-5-en-3B-ol 0.4 0.2 0.7 106. 24-ethylcholesta-5,22-dlen..38-ol 0.4 0.2 0.5 107. n-dotrlacontane 11.3 71 108. o]ean-18-en-38-ol 0.05 109. o] ean-18-en-3-one 0.4 0.08 liO. 24-ethyleholest-5-en-3B-ol 0.8 1.2 1.8 0.06 0.4 iii. 58 (ll)-24-e thylcholestan-38--ol 0.5 0.2 0.01 112. 5o ( H )-24-e thylchoI estan-3-one O. 2 O. O] ii3. hentriaeontan-16-one 0.8 114. n-trltriacontane 1.2 ii0 0.5 0.06 115. 24-ethylcholesta-3,5-dlen-7-one 0.i 116. 24-ethy~cholest-4-en-3-one 0.4 0.2 0,4 117. ]7s(H),21B(H)-homohopane 22S 1.3 0.I 3.0 118. ]Ts(H),218(H)-homohopane 22R 1.2 0.I 3.0 119. naphtho(5,2-k)fluoranthene 0.2 120. dibenzo(b,k)fluoranthene 55 0.2 ]21. naphtho(2,3-k)fluoranthene 0.3 122. dibenzo(a,e/e,1)pyrene 0.5

123. friedelan-3-one 0.2 0.i 0.2i 1.2 ]24. 302 m.w. PAH 0,05 125, dJbenzo(ah)pyrene 0.05 120. cyclic dimer of neopenty5 glycol tecephthalate 3.5 127. N-hexadecy1-N-methyl-N:octadecylamlne 0.05 128. 17o(H),218(H)-bishomohopane 2.0 129. n-tetratriacontane 2.3 140 130. ~ritrlacontan-18-one 2.0 131. n-pentatriacontane 1.5 150 132. n-hexatriacontane 1.2 71 33. pentatrlacontan-18-one 1.2

134. r!-heptatriacontarle 1.0 65 35. n-octstriacontane 0.9 40

]36. Unidentified phthalates 1.8 74 0.I 19 137. T o t a l s i l i c o n e s 17 5 . 2 25 340 3 . 7 3 .1 138. Unresolved complex mlx.ture 600 24 88!51000 29 41 40 23 430 99 86 420

926

lhe UCM is also a dist inct feature of the gas chromatographic profiles of samples 9, II and

12 (see Figure 4), those corresponding to the core obtained in the Llobregat Basin (S-5). In

sample No. lO the high sulphur content attenuates the chromatographic UCM trace but the

concentration of unresolved compounds in this sample is of the same order of magnitude as

that of sample No, II (see Table 3). In $5 core sections, the resolved compounds eluting

along the UCM encompass a complex mixture of steranes and C29-C32 hopanes having 17a(H),2!B

(H) stereochemistry. This composition contrasts with that of $4 core because of the lack of

polycyclic aromatic hydrocarbons and parallels that usually encountered in lubricating oi ls .

Contributions from other organic materials are also present in these samples. Thus, all $5

core sections contain phthalates (plasticisers). l,l,2,3,4,4-Hexachlorobuta-l,3-diene and

hexachlorobenzene (industrial solvents or synthetic intermediates) are found in sample No. 9

and diisocyanotomethylbenzenes (base products in polyurethane foam synthesis) are present iI~

sample No. I I . The occurrence of B-sitosterol and friedelan-3-one in samples Nos. lO and I I ,

respective]y, is indicative of higher plant inputs.

The UCMs are also major constituents of samples Nos. I-3 (see Table 3). However, as in

samples Nos. 7 and lO, the chromatograms of these samples are dominated by other chemicals

that elute as resolved compounds. Thus, the major peaks in samples Nos. | and 3 correspond

to phthalates, and sulphur is the predominant compound in sample No. 2. Sample l also

contains diisocyanatomethylbenzenes in significant proportion. Silicones are abundant in

samples 2 and 3.

With the exception of sample No. 4, phthalates are present in all the soil sections

considered in this study. These compounds are found world-wide in soils (17) and waters

(18). As indicated above their occurrence is related to their widespread use as plastiziers.

In this respect, small green plastics bits were visually observed in sample No. 3. In

addition to the phthalates, this sample is also characterized by a high concentration of

phthalic anhydrides which are also present in samples l , 2, lO and I f . The occurrence of

phthalic anhydrides in these samples involves a limited contact of the organic chemicals

with water. In some cases, e.g. sample 3, the preservation of the phthalic anhydrides may be

a consequence of their inclusion within hydrophobic matrices such as plastic. In others,

e.g. samples 1 and I I , the preservation of other water-reactive compounds such as diiso-

cyanatomethylbenze~}es is l ike ly indicative of restricted water circulation in the

corresponding soil level.

The presence of 24-ethylcholest-4-en-3-one in samples Nos. l and 2 is due to higher plant

inputs. In sample No. l this source is better represented by abiet~8(14)-en-18-oic and

abietic acids which are found in higher concentration than the 24-ethylsterone. In sample

No. 2, vascular vegetation residues can also be recognized by the occurrence of

24-ethylsterols.

Sulphur (S 8) is the dominant chromatographically resolved compound in samples Nos. 2, I0 and

12, and is present in signif icant proportion in samples Nos. l and I I . This compound is

927

usually produced by microbial reduction of sulfates (e.g. gypsum from masonry materials in

SI-5 samples). Sulphate-reduction is a well-known mechanism of organic matter decomposition

by anaerobic eubacteria. The presence of sulphur indicates that a portion of the organic

chemicals disposed in these samples has been microbially mineralized.

The occurrence of free sulphur is part icularly noteworthy when considering the high metal

content of these samples (e.g. 2-4% of iron). Metals usually act as a sink for hydrogen

sulphide (19, 20). The identi f icat ion of free sulphur is only expected after microbial

sulphate reduction has produced enough sulphide to bound all reactive metal from the

samples. Therefore, the extent of mineralization of the organic residues present in samples

l , 2, lO-12 is l ike ly higher than that corresponding to the mere concentrations of free

sulphur reported in Table 3.

When all metal has already reacted with microbial sulphide, sulphur may be incorporated into

the organic matter to form organo-sulphur compounds (21, 22). This is observed in sample No.

l in which 3-methyl-2-(3,7,11-trimethyldodecyl)-thiophene has been identif ied. [his compound

results from the incorporation of sulphur into phytol or phytadienes (23). The presence of

this isoprenoid/alkylthiophene evidences microbial sulphato-reduction act iv i ty at least in

some of the soils considered in this study.

CONCLUSIONS

Petroleum tar residues and lubricating oi ls constitute the major organic wastes present in

the Besos and Llobregat dumping sites considered in this study. They exhibit an important

UCM and dist inct mixtures of steranes, 17 (H),21 (H)-hopanes and polycyclic aromatic

hydrocarbons. Other compounds representing specific organic residues encompass phthalates

(present in all samples with the exception of No. 4) and phthalic anhydrides, silicones

(Nos. I-5 and l l ) , chlorobenzenamines (Nos. 4, 7 and 8), diisocyanotomethylbenzenes (Nos. ]

and l l ) , l-chloro-2-isocyanotobenzene (Nos. 7 and 8), 5-chloro-lH-benzothiazole (No. 7),

pp'-DDD (No. 7), l,l,2,3,4,4-hexachlorobuta-l,3-diene (No. 9) and hexachlorobenzene (No. 9).

The presence of water reactive compounds such as phthalic anhydrides or diisocyanatomethyl-

benzenes in some samples corresponding to deep soil sections (e.g., 1-3, lO and l l ) l ike ly

corresponds to a limited contact of the organic chemicals with water. An effect that may be

due to either inclusion into hydrophobic matrices or restricted water circulation.

The metal residues present in these dumping sites can be traced by the nickel and chromium

content. The highest concentrations of these two metals are found in sample No. 6 which is

also characterized by a high iron (25%), copper and cobalt content. Concentrations of copper

and barium higher than those found in non-polluted soils are found in samples Nos. l and 2,

and Nos. 3 and I I , respectively.

In addition to these pollutant compounds, organic molecules representing contributions from

928

higher plants are found as minor const i tuents. These encompass ab iet ic and sandaracopimaric

acids (samples Nos. I , 7, 8), unsaturated abietane hydrocarbons and retene (No. 8),

f r iedelan-3-one (Nos. 3, 6, 8 and I I ) , 24-ethyl sterols (Nos. 2, 5, 6, 8 and I0) and ketones

(Nos. I , 2, 6), and C27-C33 odd carbon numbered n-alkanes.

The presence of free sulphur and organo-sulphur compounds in most of the soi l core sections

analyzed from S1 and $5 dumps indicates that microbial sulphate-reduction is important. This

process involves the par t ia l mineral izat ion of the organic wastes disposed in these two

s i tes.

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(Rece ived in Germany 28 March 1991; accepted 3 May 1991)