Common Effluent Treatment Plant Kolkata Leather Complex Kolkata, India
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UNITED NATIONS INDUSTRIAL DEVELOPMENT ORGANISATION REGIONAL PROGRAMME FOR POLLUTION CONTROL IN THE TANNING INDUSTRY IN SOUTH EAST ASIA US/RAS/92/120-MODEL CETPs September 2001 COMMON EFFLUENT TREATMENT PLANT KOLKATA LEATHER COMPLEX KOLKATA, INDIA Prepared by A. Sahasranaman & K. V. Emmanuel Regional Programme Office Project Manager Jakov Bu1jan, SIDO, UNIDO, Vienna TABLE OF CONTENTS LIST OF SYMBOLS & ABBREVIATIONS ............................................................................. ii 1. INTRODUCTION..................................................................................................................... 1 2. KOLKATA LEATHER COMPLEX ...................................................................................... 1 3. ENVIRONMENTAL IMPACT ............................................................................................... 3 4. PLANNING OF EFFLUENT MANAGEMENT IN KLC .................................................... 3 5. CEPT – DESCRIPTION .......................................................................................................... 4 5.1. Preliminary treatment in tanneries ...................................................................................... 4 5.2. Sewerage and stormwater collection ................................................................................... 4 6. CETP – BASIC PARAMETERS & OPTIONS ..................................................................... 5 6.1. Influent characteristics ........................................................................................................ 5 6.2. Alternative systems for tannery wastewater treatment ....................................................... 6 7. FEATURES OF SELECTED TECHNOLOGY .................................................................... 6 7.1. Preliminary treatment .......................................................................................................... 6 7.2. Physical-chemical treatment (coagulation/flocculation/sedimentation) ............................. 6 7.3. Biological treatment (high load activated sludge) .............................................................. 7 7.4. Sludge treatment and disposal ............................................................................................. 7 7.5. Sludge and solid waste disposal .......................................................................................... 7 8. ORGANISATIONAL FRAMEWORK FOR WASTE MANAGEMENT .......................... 9 9. PROPOSED WASTEWATER LEVY SYSTEM ................................................................. 10 10. WASTEWATER LABORATORY ..................................................................................... 11 11. PROJECT IMPLEMENTATION ....................................................................................... 11 12. COST ...................................................................................................................................... 12 12.1. Capital Cost ..................................................................................................................... 12 12.2. Operating Cost: ............................................................................................................... 12 12.3. Landfill ............................................................................................................................ 12 13. PRESENT STATUS ............................................................................................................. 12 Annexures Annex 1 Dwg. 1 : Layout of the leather complex………………………………………... 13 Dwg. 2 : Layout of CETP………………………………………………………. 14 Dwg. 3 : Flow diagram of CETP……………………………………………….. 15 i LIST OF SYMBOLS & ABBREVIATIONS BOD5 Biological oxygen demand BOT Build-operate-transfer CCRP Central chromium recovery plant CETP Common effluent treatment plant KLC Kolkata Leather Complex CLRI Central Leather Research Institute COD Chemical oxygen demand GoWB Government of West Bengal ha Hectares INR Indian Rupees m meter mg/l milligram/litre mm millimeter MLD Million litres per day MoEF Ministry of Environment and Forests HDPE High density poly-ethylene PE Poly-electrolyte PVC Poly-vinyl chloride SWCD Solid waste collection department SWDD Solid waste disposal department SWDS Solid waste disposal system SWMS Solid waste management section UASB Upflow anaerobic sludge blanket system UNIDO United Nations Industrial Development Organization UNIDO-RePO UNIDO Regional Programme Office US-EPA United States Environmental Protection Agency WBPCB West Bengal Pollution Control Board Rate of exchange: 1 US $ = INR 46.80 ii 1. INTRODUCTION Kolkata, the capital of West Bengal state in India, is an important tanning centre of India. Currently there are 538 tanneries operational in Kolkata, distributed over 3 clusters. - Tangra with 267 units, processing mainly hides and an estimated production capacity of 31 million m2 leather per year (565 t hides per day) - Tiljala with 223 units, processing mainly hides and an estimated production capacity of 7 million m2 leather per year (125 t hides per day) - Topsia with 48 units, processing mainly skins and an estimated production capacity of 14 million m2 leather per year (160 t hides per day). The tanning activity in these clusters started several decades ago when these areas were away from the populated parts of the city of Kolkata. But of late these clusters have come well within densely populated areas of the city. The total estimated production capacity equals 52 million m2 leather per year (850 t hides per day). However, the current reported leather production is less than 50% of the estimated capacity (about 23 million m2). Chrome tanning is predominantly applied (85%), whereas vegetable (bag) tanning is of less importance (15%). According to CLRI, the number of workers employed in the tanneries is about 30,000. The tanneries are currently surrounded by densely populated residential areas. There is thus no space for installation of pollution control systems, expansion or modernization. The environmental problems in these areas have become serious due to the absence of wastewater and solid waste management systems. The tanneries discharge their wastewater into roadside drains, which due to frequent blockages, cause flooding of streets and premises. Solid wastes are disposed in a completely uncontrolled manner. Stench from the tannery clusters is continuously present in the surrounding area. The effluent receiving waters, the Bhangar and the Beleghata canals, are seriously polluted. In 1999, the CLRI prepared an inventory of the operational tanneries in the 3 clusters. The report summarises data on 303 existing tanneries with respect to production processes and quantities: - Raw-Wet blue- Finished leather: 206 units processing about 490 t hides per day - Crust- Finished leather: 26 units processing about 142 t per day - Mixed processes: 2 units processing 1.3 t per day - Wet blue - Finished leather: 33 units processing 240 t per day - Raw - Wet blue: 34 tanneries processing about 109 t per day 2. KOLKATA LEATHER COMPLEX Government of West Bengal had decided in as early as 1992, that the tanneries had to be relocated to a new modern complex, complete with a CETP to properly treat the effluent discharged. CLRI, Chennai had prepared & submitted a concept report in this regard in 1993, under the UNIDO-assisted National Leather Development Programme. The GoWB began to take 1 steps towards implementation of the Kolkata Leather Complex soon after. However when the complaints regarding the environmental pollution from these tanneries became strident, considering all related aspects, the Supreme Court of India directed the tanneries in 1996 to migrate to the new complex to be developed by the state Government. The order of the Supreme Court gave an added impetus and speed to the implementation of the Kolkata Leather Complex already begun by the government. It was decided that this complex would accommodate all industrial and commercial activities related to leather manufacture and production of leather goods. For this purpose 438 ha land had been identified in the district South 24 Parganas, about 22 km from Kolkata on the eastern side of the E.M. Bypass, along the road from Kolkata to Basanti and adjacent to the SWF (or Bhangar Kata) canal. Much of the land being government property, the possession of such land was taken over by the GoWB. The State Government decided to implement the KLC project on BOT basis as it neither had the technical expertise nor the resources. The BOT contract was awarded to M.L. Dalmiya & Co. Ltd., 32, Shakespeare Sarani, Kolkata in 1997. Until now, 300 ha of land has been taken possession of and 84 ha is currently being purchased. An area of 54 ha is under litigation. Work on construction of the KLC started in 1997. Current works include land filling, construction of roads, canals and water bodies. The ground level of the entire area has been raised by about 1 m by land filling. The area is completely flat. The ground level is 1.8 m below the level of the Kolkata - Basanti road. The estimated total electricity requirement of KLC is 80 MVA. Electricity will be supplied by WBSEB at l32 KV level. A sub station has been set up by the GoWB. Water will be supplied by the BOT contractor from groundwater resources by means of 25 tube wells, each at a depth of 300 m with an estimated yield of 36.75 MLD, which is sufficient to meet the demands of the KLC. Additional water supply will be provided from surface