Decision making and economical optimization of a city scale solid waste management system: An integrated model simulation on Kolkata, India

Abstract

Kolkata with total population of 11 million as on 2022 generates 800–850 gm of MSW per capita per day which is expected to reach 1500 g/capita/day by 2040. The waste generated from 16 number of boroughs is openly disposed to the major non-engineered eastern landfill site Dhapa without having any proper source segregation, processing and treatment. The estimated present cost of total solid waste management is around 2,507,238 Rs/day which demands an urgent economic analysis through cost optimization. Dhapa with total landfill area of 40 ha is exhausted with its 30 years long legacy waste. As Hon’ble National Green Tribunal (NGT) has mandated bio-mining of old landfill site in India, it is expected that the Dhapa landfill area will be reclaimed by 2024. The objective of this paper is to implement a futuristic Integrated Solid Waste Management (ISWM) model over the existing SWM scenario of Kolkata incorporating an eastern transfer station consisting sorting station, incineration and composting plant followed by converting Dhapa as a major engineered landfill site. Using LINGO optimization software, the model was run and solved. As a result, a total reduction in waste management cost by 43% and landfilling cost by 48% is possible. Further vehicle optimization shows reduction in total SWM cost and waste transportation cost by 70% and 16% respectively. If the SWM system is operated by optimized compactors, a total cost minimization of 73% is achievable. This generic methodology can be applicable to any inefficient waste management system of Indian cities to cope up with the economic aspects and reaching towards sustainability.