VALORIZATION OF SOLID WASTE FROM THE TANNERY INDUSTRY: PREPARATION OF ADSORBENT BY COST EFFECTIVE METHOD

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1 VALORIZATION OF SOLID WASTE FROM THE TANNERY INDUSTRY: PREPARATION OF ADSORBENT BY COST EFFECTIVE METHOD S.Vanitha 1, M.Suresh kumar 2 Department of civil Engineering Bharath university Chennai, Indian ABSTRACT Treatment of solid wastes is not cost effective, posing economic burden to the tanners. The objective of this paper is to review the kinds of solid wastes generated in leather industry and the useful technologies developed to overcome the solid wastes problem and use of solid waste as useful one. In the common effluent treatment plant Dual media filter is used to remove color, Total suspended solid, turbidity. In the dual media filter sand and pebbles and carbon are used for removing suspended solid and color. Instead these filter media we can use solid waste from tannery industries. The main feature of this project is to increase the value creation process through the research i.e, utilization of solid waste with economical method and save the environment. KEY WORDS Tannery, Adsorption, leather waste, SGLW, solid waste, waste water 1.1 INTRODUCTION Water is one of the essential enablers of life on earth. But pure water is not available to a large fraction of the population of the planet. While availability is an issue, contamination is another major concern which threatens the survival of many. The Tannery Industry in India is one of the oldest and largest industries in the country. These require large volume of water of high purity and generate equally large volume of waste ISSN: Page 33

2 water which is highly complex and polluted. In the present study, it was aimed to carry out experiments using Steamed Ground Leather Waste (SGLW) for the removal of Color, turbidity and Total Suspended Solid from the combined waste water of Tannery Industries. Due to the new directions imposed by the concept of Sustainable Development, the Integrated Management of Solid Wastes is an important key issue, mainly because of the potential negative effects against environment of wastes production and uncontrolled storage. The leather tanning industrial processing gives high and diverse quantities of solid wastes that can be valorized and/or recoveries of useful products. Assurance of the quality of water resources is representing a demand and a need of our days in conditions of reductions of the natural resources. In this context, there are important to be applied some efficient technologies and procedures for industrial effluent treatment in order to reuse the treated effluent in the technological process or to protect the tannery industries to survives. 1.2 TANNERY INDUSTRIES PROCESS A tannery is the term for a place where the skins are processed. Tanning leather involves a process which permanently alters the protein structure of skin. Making "rawhide" (untanned but worked hide) does not require the use of tannin. Rawhide is made by removing the flesh and fat and then the hairby use of an aqueous solution (this process is often called "liming" when using lime and water or "bucking" when using wood ash (lye) and water), then scraping over a beam with a somewhat dull knife, then drying. Tanning is the process of treating skins of animals to produce leather, which is more durable and less susceptible to decomposition. in the tanning of leather lot of solid waste and liquid waste has generated these lead so much problem to environment The Figure presents a flow diagram of the tanning-process. Hides are a by-product of slaughter activities and can be processed into a wide range of end products. For each end product, the tanning process is different and the kind and amount of waste produced may vary enormously. ISSN: Page 34

3 TANNERY PROCESS AND WASTE GENERATION PROCESS WASTE RAW HIDES PRETANNING -Soking -Fleshing -Unhairing + Liming -Bating -Pickling Fleshings BOD, COD, SS, Salts, Organic N H 2 S, NH 3 MAIN TANNING -Chrome tanning -Sammying -Sorting -Splitting -Shaving Shavings, Trimmings BOD, COD, SS, Salts, Chrome WET-FINISHING -Neutrallisation -Retanning -Drum Dyeing -Fatllqueing -Sammying -Setting -Drying Trimmings BOD, COD, Chrome, Dyes, Fat FINISHING OPERATION LEATHER -Conditioning -Staking -Buffing -Trimming -Finishing Solid Residue Liquid Residue Solvents, formaldehyde ISSN: Page 35

4 The chemicals traditionally used for tanning have been derived from plants, whereas the most common process nowadays is a combination of chrome salts (chrome tanning) and readily usable vegetable extracts (vegetable tanning). While chrome tanned shoe leather is the most widely produced leather, this kind of leather will receive most attention in the following. In most cases raw hides produced at slaughterhouses are preserved by pickling and drying for transport to tanneries and further treatment. In the very few cases that hides are instantly tanned there is no need for preservation. During the tanning process at least ±300 kg chemicals (lime, salt etc.) is added per ton of hides. PROBLEM STATEMENT: Solid waste from tannery industries - land pollution, air pollution, water pollution Waste water from tannery industries water pollution, smell, land pollution Present treatment high cost, availability, regeneration, time consuming. Solid waste During the processing of the production of fresh hides, so much of solid waste is produced.the following table describe the solid waste generation. Pretanning Tanning Finishing Trimmings Y Y Y Fleshings Y N N Wet Blue Split N Y N Buffing Dust N N Y Collection and safe disposal of solid waste especially chrome containing solid waste and sludge is normally monitored by environmental authorities and associated with costs. Conversion of solid waste into by-products not only reduce pollution load, it can also be commercially beneficial. This represents great potential for producing increased returns to tannery processing through deriving value from wastes. In any event, reduction of waste is essential in order to meet demands for reduced pollution load from tanneries. ISSN: Page 36

5 Wastewater Every tanning process step, with exception of the crust finishing operations, produces wastewater. An average of 35 m 3 is produced per ton of raw hide. This wastewater contains: - salts (Cl), fat, protein, preservatives (soaking); - lime and ammonium salts, ammonia, protein (hair), and sulphides (fleshing, trimming, bating); - chromium(salts) and polyphenolic compounds (tanning); and - dye and solvent chemicals (wet-finishing). Solid waste produced consists of fleshings containing lime, chromium containing wet-blue shavings and of trimmings (leather). in general be undertaken without too many efforts and that the costs and energy required are lower than those for the treatment of wastewater. POLLUTANTS OF TANNERY EFFLUENT: Appearance, Odor, ph, Turbidity, Total solids, Total suspended solids, Total dissolved Chlorides, BOD5, COD, Chromium. 1.3 ADSORPTION: Adsorption is a process by which a gas, liquid, or solute (substance in solution) binds to the surface of a solid or liquid (called the adsorbent), forming a film of molecules or atoms (called the adsorbate). Adsorption is a consequence of attractive interactions between the surface of the adsorbent and the species being adsorbed. In the bulk of an adsorbent, all the bonding requirements (be they ionic, covalent, or metallic) of the constituent atoms of the material are fulfilled by other atoms in the material. However, atoms on the surface of the adsorbent are not wholly surrounded by other adsorbent atoms and therefore can attract molecules of the adsorbate. The exact nature of the bonding depends on details of the species involved. ISSN: Page 37

6 1.4 OBJECTIVES The main objective of this study is to contribute in the search for less expensive adsorbents and their utilization possibility, such as (Steamed Ground Leather Waste) SGLW for the elimination of Total Suspended Solid, turbidity and color from waste water from tannery. To determine the effectiveness of SGLW in removing color, Turbidity, TSS and other pollutant from tannery industries wastewater. To determine the properties of SGLW and investigate the potential use of SGLW. To design the FILTER MEDIA COLUMN. 1.5 METHODOLOGY PREPARATION OF SGLW DESIGN AND FABIRCATION OF PACKED BED COLUMN EXPERIMENT OF EFFLUENT FROM TERITARY CLARIFIER WITH PACKED BED COLUMN EVALUATION OF RESULT ISSN: Page 38

7 1.6 MAKING OF ADSORBENT (SGLW) The following diagram shows the making of Steamed Ground Leather Waste Leather Waste from Tannery Industries Heating vessel STEAM Pulverizer Steamed Ground Leather Waste (SGLW) Leather Wastes are getting from Tannery industries are heated by the help of steam. Then these materials are get in to small pieces by using Pulverizer. The final materials we called as Steamed Ground Leather Waste (SGLW). Leather Waste from Tannery Industrie Steamed Ground Leather Waste (SGLW) ISSN: Page 39

8 Properties of SGLW S.NO. PARAMETER UNIT RESULT 1 Physical State Solid 2 Color Black 3 Texture Dry pellets 4 P H at 30.7 o C Loss on Ignition at 550 O C % 50.76% 6 Lead (TCLP) mg/l < Cadmium (TCLP) mg/l Chromium (TCLP) mg/l Zinc (TCLP) mg/l < Copper (TCLP) mg/l < Loss on Drying % Total Cyanide ppm <1 13 Calorific Value cal/g ISSN: Page 40

9 1.7 DESIGN OF FILTER MEDIA COLUMN DIAGRAM OF FILTER MEDIA COLUMN INLET FREE BOARD 15 cm (40 % free board) FILTER MEDIA 22 cm (60 % packed bed) PERFORATED PLATE 18 cm OUT LET ISSN: Page 41

10 DESIGN DATA OF PACKED BED COLUMN Discharge ( Q ) Total Height of the column (packed bed + free board) Diameter of the column Height of packed bed Height of free board Distance between the holes in the perforated plate = 2970 Lit /Hr = 37 cm = 11 cm = 22 cm = 15 cm = 1 cm PERFORATED PLATE DIAGRAM 1 cm ISSN: Page 42

11 1.8 TREATMENT OF TANNERY INDUSTRIAL WASTE WATER EFFLUENT FROM TANNERY INDUSTRIES BAR SCREEN DRUM SCREEN EQULIZATION TANK FLASH MIXER LIME + ALUM + POLYACROYATE PRIMARY CLARIFIER AERATION TANK SECONDARY CLARIFIER FLASH MIXER LIME +SODAASH TERITARY CLARIFIER DUAL MEDIA FILTER UF, OS,RO REJECT CLEAN WATER FOR REUSE ISSN: Page 43

12 1.9 EXPERIMENT: The experiment has done in the laboratory, where the packed bed coulmn filled with different kind of materials like Steamed Ground Leather Waste(SGLW), Carbon, Sand.( 60% materials and 40% free board) and the effluent from reactor clarifier was taken for testing. Then the out let water was tested and dates are analyzed. METHOD 1 Setp 1: The column filled with SGWL, then the RC sample (REACTOR CLARIFIER) OR TERITARY CLARIFIER are pour in to the column. The outlet has collected, and then tested. Step 2: The Column has filled with full CARBON material, and then the RC sample is poured in to the column. The outlet has collected, and then tested. Step 3: The Column has filled with full 40% of CARBON and 60% of SGWL materials, and then the RC sample is poured in to the column. The outlet has collected, and then tested. Step 4: The Column has filled with full 80% of CARBON and 20% of SGWL materials, and then the RC sample is poured in to the column. The outlet has collected, and then tested. Step 5: The Column has filled with full 60% of CARBON and 40% of SGWL materials, and then the RC sample is poured in to the column. The outlet has collected, and then tested. ISSN: Page 44

13 The comparative Analysis of SGLW, CARBON, 40% CARBON+60% SGLW, 20% CARBON+80% SGLW, 60% CARBON+40% SGLW as shown in the table. S.No. PARAMETERS UNIT RC SAMPLE SGLW CARBON 40% CARBON+ 60% SGLW 20% CARBON+ 80% SGLW 60% CARBON+ 40% SGLW 1 PH C O D mg/l CONDUCTIVITY TDS mg/l TOTAL HARDNESS mg/l CL mg/l SULPHIDE BDL BDL BDL BDL BDL BDL BDL 8 TUBIDITY NTU COLOR LIGGHT BROWN CLEAR LIGHT BROWN SOME WHAT CLEAR NOT CLEAR CLEAR The comparative Analysis result ISSN: Page 45

14 METHOD 2 Setp 1: The column filled with SGWL and SAND, then the RC sample (REACTOR CLARIFIER) OR TERITARY CLARIFIER are pour in to the column. The outlet has collected, and then tested. Step 2: The Column has filled with SGLW and CARBON material, and then the RC sample is poured in to the column. The outlet has collected, and then tested. Step 3: The Column has filled with SGWL, CARBON and SAND materials, and then the RC sample is poured in to the column. The outlet has collected, and then tested. The comparative Analysis result as shown in the table S.No. PARAMETERS UNIT SAND + SGLW CARBON + SGLW CARBON + SGLW + SAND 1 PH C O D mg/l CONDUCTIVITY TDS mg/l TOTAL HARDNESS mg/l CL mg/l SULPHIDE BDL BDL BDL BDL 8 TUBIDIY NTU COLOR CLEAR CLEAR AFTER SOME TIME SOME WHAT CLEAR ISSN: Page 46

15 SGLW + SAND SGLW + CARBON GLW + CARBON + SAND Color Display 1.Reacter Clarifier (RC), 2. SGLW+CARBON. ISSN: Page 47

16 The permissible limits for out let of Treated water from CETP are: S.No. PARAMETERS AVG. TOTAL POLL. LOAD TO PERMISSIBLE LIMITS CETP 1 ph COD mg/l 3 BOD mg/l 4 TSS mg/l 5 TDS mg/l 6 Cl mg/l 7 SULPHIDE H 2 S 20 2 mg/l 8 SULPHATE SO mg/l 9 Cr mg/l 10 TOTAL HARDNESS mg/l S.No. PARAMETERS UNIT NORMAL DUAL MEDIA (CARBON, SAND,PEBBLES) DESIGNED PACKED BED (40% SGLW + 60%CARBON ) 1 PH C O D mg/l CONDUCTIVITY TDS mg/l TOTAL HARDNESS mg/l CL mg/l SULPHIDE BDL BDL BDL 8 TUBIDIY NTU COLOR CLEAR CLEAR Table Comparison of Normal Dual Media Filter and Designed Packed Bed ISSN: Page 48

17 CONCLUSION Utilization of solid waste from tannery industries is very important in the present scenario, so the valorization of these solid waste are done by the conversion of solid leather waste in to useful STEAMED GROUND LEATHER WASTE (SGLW). These SGLW used as adsorbent in the treatment of waste water in the tannery industries.generally leather material have proteins. These proteins have the characteristics of adsorption of ions. So this characteristic is used to remove color, turbidity. Design and fabrication of packed bed column has done for doing adsorption process with SGLW. The outlet from the reactor clarifier (RC) sample has taken into analysis. The comparison have made with normal Dual Media Filter and designed adsorption column (SGLW+CARBON). From the comparison we noticed that the color, turbidity, and TSS was successfully removed with composition of 40% of SGLW AND 60% of CARBON.. So tannery waste can be used as adsorbent in packed adsorption column, and further study is needed on disposal techniques behind SGLW. REFERENCES 1. Alexander, K.T.W., Corning, D.R., Cory, N.J., Donohue, V.J., Sykes, R.L., (1991). Environmental and safety issues clean technology and environmental auditing. J. Soc. Leather Technol. Chem. 76 (1), Brown, E.M., Taylor, M.M., Marmer, W.N., (1996). Production and potential uses of coproducts from solid tannery waste. J. Am. Leather Chem. Assoc. 91 (10), Cabeza L.F., Taylor M.M., DiMario G.L., Brown E.M., Marmer W.N.,Carrio R., Celma P.J., Cot J.(1998). Processing of leather waste: Pilot scale studies on chrome shavings. Isolation of potentially valuable protein products and chromium. Waste Management, 12, Cabeza, L.F., Mcaloon, A.J., Yee, W.C., et al., (1998). Process simulation and cost estimation of treatment of chromium-containing leather waste. J. Am. Leather Chem. Assoc. 93 (12), Changadao Mu, Wei Lin, Mingrang Zhang, Qingshi Zhu,.(2003) Towards zero discharge of chromium-containing leather waste through improved alkali hydrolysis Waste Management 23, ISSN: Page 49

18 6. Czapla, C. and Bart, H. J. (2000) Characterization and modeling of the extraction kinetics of organic acids considering boundary layer charge effects. Chemical Engineering & Technology, 23(12), Fela K., Wieczorek-Ciurowa K.(2010). Heavy metals in ashes from thermal treatment of leather industry solid wastes. Proceedings of 15 th International Conference on Heavy Metals in the Environment, Chemical Faculty, Gdansk University of Technology, Gdańsk, Kanagararaj,J., Velappan, K. C., Chandra Babu, N. K.m, and sadulla,s.(2006). Solid Wastes generation in the leather industry and its utilization for cleaner environment Journal of Scientific & Industrial Research, Vol. 65,, pp Lawrence, M. J. and Ress, G. D. Microemulsion (2000) -based media as novel drug delivery systems. Advanced Drug Delivery Reviews, 45(1), ISSN: Page 50