Textile Sludge Degradation and Biogas Generation

*1Amita Deokate, **2S. M.Bhosale, ***3M.M.Wagh*1, **2Department of Environmental Science and Technology,Department of Technology, Shivaji University, Kolhapur, email:amitadeokate1993@gmail.com, 09881257306***3 Department of Energy Technology, Department ofTechnology, Shivaji University, Kolhapur,energyunishivaji@gmail.com, 09423981785

Abstract: Textile industry is growing on an enormous ratedue the capital demand of the product cotton, wool andsynthetics. The waste water generated from differentmanufacturing processes in a point to threat because of itstoxicity. The toxicity mainly comes from presence of heavymetals, chemicals and different compounds used in differentmanufacturing processes.among these heavy metals is of greatconcerns. The heavy such as Pb, Cd, Ni, Cu, As, Cr etc. arefound in textile sludge. These heavy metals cannot beneglected as they are harmful and toxic to the both humans andenvironment same is in the case of chemicals and compoundsused in the textile industry. The heavy metals are detected byAtomic Absorption Spectrometry (AAS)[2]. By this technique itis also studied whether the heavy metals are within safelimits or not. Over the years, several wastewater treatmenttechnologies have been designed and operated at full scalewhile some more recent ones are on experimental scale. Thesetechnologies are classified as physical, aquatic, orterrestrial systems. Recent studies have confirmed that inaquatic wastewater treatment systems, aquatic weeds are low-cost powerful bio-agents which purify wastewater lying underthem by physical, chemical and biological actions. Among theseaquatic weeds, water hyacinth (Eichhornia Crassipes) has receivedgreat attention because of its obstinacy and highproductivity. Water hyacinth is also having a promisingpotential for the removal of toxic metals and other pollutantsfrom aquatic environments though the purification of sewage by

water hyacinth has not yet been generally embraced in someparts of the world. A majorly developed country, waterhyacinth has been used to remove nutrients or pollutants fromwastewaters. Water Hyacinth plays important role in removal ofheavy metal as well as it becomes admixture by its own afterthe completion of extraction period of heavy metal. Theremaining sludge is used as slurry with cow dung and waterhyacinth. The whole model is kept for minimum 30 days and theformation of biogas takes place that can use for domesticpurpose as cooking, electricity generation if needed. Thesludge generated from the biogas plant is used as fertilizers.The present study was carried out to determine concentrationof heavy metals (Pb,Cd,Zn,Cu,Cr,Fe and Mn) in the sludgesample, UV Spectrophotometer method was employed for theanalysis of such heavy metal.

1.Introduction:

The term Waste water can be defined as any material thatenters the waste management system. a waste management processare organized programs and central facility used for thefinal disposal of waste by recycling, reuse, composting,incineration and now a days for energy extraction. Energy isone of basic requirements of all living beings. It playsdecisive role in the sustainable socio-economic developmentand improved quality of life. The Ministry of Environment AndForest Of India had issued Industrial solid waste (managementand handling) rules in the year 2000 for scientific Industrialsolid waste management, which ensures proper collectionsegregation, transportation, processing and disposal of sludgeand up gradation of existing facilities to arrestcontamination of soil and ground water. As per the provisionsCPCB has been assigned to monitor the implementation of theserules, and the industries will be required to submit annualreports regarding status of sludge in their areas to the CPCB.Textile industry is growing on an enormous rate due thecapital demand of the product cotton, wool and synthetics. The

waste water generated from different manufacturing processesin a point to threat because of its toxicity. The toxicitymainly comes from presence of heavy metals, chemicals anddifferent compounds used in different manufacturing processes;among this heavy metals is of great concerns. A majorlydeveloped country, water hyacinth has been used to removenutrients or pollutants from wastewaters.Water Hyacinth playsimportant role in removal of heavy metal as well as it becomesadmixture by its own after the completion of extraction periodof heavy metal. The remaining sludge is used as slurry withcow dung and water hyacinth. The whole model is kept forminimum 30 days and the formation of biogas takes place thatcan use for domestic purpose as cooking, electricitygeneration if needed. The sludge generated from the biogasplant is used as fertilizers.2 Process of anaerobic Digestion: Anaerobic Digestion (AD) is a microbiological process ofdecomposition of organic matter in absence of oxygen. The mainproducts of this process are biogas and digestate. Biogas is acombustible gas, consisting primarily of methane and carbondioxide. Digestate is the decomposed substrate, resulted fromthe production of biogas. During AD, very little heat isgenerated in contrast to aerobic decomposition (in presence ofoxygen), like it is the case of composting. The energy, whichis chemically bounded in the substrate, remains mainly in theproduced biogas, in form of methane.These organismssuccessively decompose the products of the previous steps. Thesimplified diagram of the AD process, shown in Figure,highlights the four main process steps: hydrolysis,acidogenesis, acetogenesis, and methanogenesis

Figure1:process of anaerobic digestion

3.MATERIALS AND METHOD The experimental plant is semi continuous type in which thepredetermined quantity of feed material diluted with wateris charged into the digester from one side(inlet) once aday and the digested material equivalent to volume feedflows out of the digester from other side(outlet) .Digester volume always remain constant. Theexperimental plant consist of two stages ,The first stageconsist of anaerobic digester along with feed pipe ,outletpipe, water jacketing and vent attached with nipple for gasflow is provided. The digester is covered with gascollector which has shape of inverted funnel and it movesalong the guide bar after the gas is liberated from theslurry. Second stage comprises of gas holder which also hasa cover at its top has two gas vents attached. One of thevent is provided with rubber pipe whose end is attached toburner The two cylinders are connected to each other byrubber pipe.

Fig 2: Flow sheet of the experimental pilotplant

4. Description of Components:

4.1.Digester:The main digester is cylindrical in shape and is made ofmild steel. The diameter of digester is 0.205 m and heightis 0.240 m. The volume of digester is 8 liters. Frominternal side water jacketing compartment is provided toprevent atmospheric biogas loss .The water jacketingcompartment houses the gas collected cover. The digester isprovided 1 inch MS pipe meant for discharge of digesterslurry. This pipe serves as a outlet for digested sludge.At the bottom of the digester cylinder, a open collar isfixed which is meant for guide bar to rest one of its end.On the periphery of the digester two MS angles are weldedwhich form supporting frame of height 0.12 m for the guidebar and the gas collector cover.

4.2. Gas Collector Cover: The cylindrical digester being anaerobic is provided withMS gas collector cover which slides (up and down) over theguide bar and rest in water jacket compartment. Thediameter of cover is 0.19 m and height is 0.15 m .The gascollector cover at top has conical shape and height ofconical part is 0.04 m. The gas collector cover is providedwith 3/4th inch MS feed pipe. It has a saucure arrangementat top so that the substrate does not fall away whilefeeding the digester also at the top of the gas collector agas outlet vent is provided. Volume of the gas collectorcover including the top conical shape is 4.37 lit. Theguide bar has 10 mm diameter.

4.3.Gas holder: The gas holder is open M.S cylinder of 0.285 metersdiameter and height 0.33 meter. On the periphery of the gasholder two M.S angles of height 0.34 mts are welded forsupporting the central guide bar and floating dome. At thebottom of gas holder a open collar is welded so that oneend of guide bar rests in it.4.4.Floating dome:

The gas holder is provided with a cover which is likeinverted cylinder with conical shape at the top.

Figure2:digester components

5.Analytical Methods:5.1.Treatments composition and measured parameters: The experiment consisted in use the cow dung as amicroorganism’s inoculation source and moisture correctorin the treatments composed by textile sludge. Treatmentsconsisted the following proportions: 70% textile sludge+30% cow dung. The initial parameters such as pH,temperature were maintained. 5.2.Conducting the laboratory experiment: The experiment was conducted at the Environmentalscience and technology laboratory. For heavy metal removalplastic bottle used in that sludge were used with waterhyacinth, which helps to minimize the heavy metalconcentration. Biostabilization systems were built in 8liter M.S digester, in which 3 kg cow dung were added. Alsowater added in ratio 1:1. The inoculum is then added with

textile sludge in the ration 3:7 the total concentrationwas 8 kg filled in 21 liter gas holder capacitor. Aftergeneration of gas the slurry added with textile sludge inthe ratio of 3:7 and kept for the degradation. After 20days the gas was generated which was tested by burner, ablue flame generated that states generation of methane. 5.3.Water hyacinth growth mechanism:The CETP sludge taken weighing 5 kg which was put inplastic container, 1 liter water is added to make theslurry with proper interval of time.Water hyacinth wasgrown on provided media and kept for heavy metal removal.With proper observation 10 days the water hyacinth wascompletely grown and that was set up for 21 days to uptakeheavy metals from the sludge.6.RESULT AND DISCUSSION: The experimental work of studying the performanceevaluation of pilot scale biogas plant for industrialsludge was done at Environmental science and technologylaboratory, Department of Technology, Shivaji UniversityKolhapur.After feeding, the digester effluent was collectedand analysis of various parameters was done soon after.

Sr.no.

Heavy Metals

Wavelengths(nm)

Initialconcentration

(mg/l)

Finalconcentratio

n(mg/l)

1 Cu 317.933 2.10 1.902 Mg 285.200 1.45 1.383 Cr 267.716 0.95 0.864 Mn 294.920 1.60 1.54

Table1:concentration of heavy metals

7.CONCLUSION:

Performance of the digester largely depends onfluctuations in operating parameters. As discussed earlierthe parameters are sensitive to small changes inenvironment and hence efforts are to closely monitor theparameters and take appropriate measures to maintain thestability of digester. The stability of the digester has tobe maintained to achieve optimum gas production withmaximum efficiency.The biodegradability of a feedstock isindicated by biogas or methane yield and percentage ofsolids (total solids or volatile solids) that are destroyedin the anaerobic digestion. The biogas or methane yield ismeasured by the amount of biogas or methane that can beproduced per unit of volatile solids contained in thefeedstock after subjecting it to anaerobic digestion for asufficient amount of time under a given temperature.Anaerobic digestion is a preferred method for energyrecovery from food waste, because it has severaladvantages, including volume reduction, waste stabilizationand biogas recovery. The biogas when used offers smokelesscooking. The byproduct obtained after drying is compostwhich is chemically stable and attracts the user because ofless odor and cleaner appearance. The experimental plantwas inside the laboratory that is in shady place, but ifthe plant is installed in open air the gas production canincrease due to direct heating by sunlight.

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