Integrated municipal solid wastes management in a metropolitan city

Abstract

Waste generation is an integral consequence of human civilization. Improper management and crude dumping of municipal solid waste (MSW) leads to high emission of GHGs like CH4, CO2 and other toxic gases, generation of highly polluted leachate and degradation of natural resources. As the existing conventional MSW management is unable to satisfy the goal of sustainable development, integrated solid waste management system (ISWMS) is required to achieve this goal. A methodology has been developed to find the optimized path to shift towards integrated approach. In this study a major metropolitan city Kolkata in a developing country, India, having 9 million total population with 3000 MT/day MSW generation is considered to develop this methodology. A significant amount (3106 MT/year) of air pollutants are generated from existing MSW transportation sector of Kolkata. The noise pollution study on existing situation reveals that the group of workers worst affected are the drivers and laborers of bulldozer, pay-loader fed tipper truck and manually loaded tipper truck. From existing system, 5×109 MJ energy and 3 MW power plant can be supported for 10 years period after scientific closure of the existing open dump site, Dhapa. From proposed ELF 3.5×1010 MJ energy and 10MW power plants could be supported for 20 years. A generic MSW management linear programming (LP) model is developed considering its different components and economics, validated, then applied to the proposed ISWMS and compared with the existing to achieve optimized cost effective sustainable solution methodology for developing countries like India. The analysis of proposed ISWM, LP model indicates that the total optimum SWM cost for this model with same cost configuration is ~46% lower than the total SWM cost in existing optimized model. In the proposed ISWMS, reduction in total land requirement will be 37% which will be a substantial amount of cost and valuable land resource saving. As good quality of compost will be produced, fertility of land will be enhanced and heavy metal pollution in the soil and food chain will be minimized. Above studies indicates substantial amount of pollution reduction possibilities as well as cost savings in ISWMS than the existing system. The study conclusively has delivered a methodology to achieve a sustainable solution of MSW management system in developing countries like India.