Dumping Yard-Free Society Through Sustainable Solid Waste Management: A Case Study of Varanasi City

Abstract

The Kolkata Solid Waste Management Improvement Project (KSWMIP) proposes an integrated municipal solid waste management system for six waste bank municipalities of river Hoogly, namely Champdani, Baidyabati, Serampore, Rishra, Konnagar and Uttarpara-Kotrung, which is being executed by the Kolkata Metropolitan Development Authority (KMDA) in association with the six munic- ipalities under funding support from the Japanese International Cooperation Agency (JICA). Segregated waste from two bin system will be transported to transfer stations of the municipalities. Recyclables will be taken out for reuse, and biodegradable portion will be composted by windrow process. Inerts and rejects (60% of the total) will be transported to Regional Waste Management Centre (RWMC) for sanitary landfilling along with 50 m3/day of septic tank sludge (septage). Aim of this work is to manage leachate and septage in RWMC which consists of sanitary landfill (SLF) of 140,000 m3 capacity, approximate life of 16 years; septage treatment facility of capacity 125 m3/day with dilution water and leachate treatment facility of capacity 816 m3/day. Septage will be treated by the single-stage anaerobic sludge digester with 40 days detention period, and digested sludge will be sent to Centrifuge for dewatering. Supernatant liquor from anaerobic sludge digester (75.37 m3/day) and centrate from centrifuge (40.6 m3/day) will be discharged to the leachate treatment system for further treatment. Mixture of treated septage (116 m3/day) and leachate (700 m3/day) will be treated first in the facul- tative aerated lagoon-I, then in the facultative aerated lagoon-II in series. Treated effluent from the facultative aerated lagoon II will be transferred by gravity to the facultative cum sedimentation pond for further treatment. Treated effluent will be discharged in the Dankuni Canal by gravity after meeting the discharge standards of inland surface water, and a part of it will be used as dilution water in the septage treatment system and also for other uses within the RWMC.