Development of a framework for integrated solid waste management : an application to Kekirawa pradeshiya sabha

Abstract

Municipal solid waste management (MSWM) has evolved into a national concern affecting every individual in Sri Lanka. Poorly managed MSW affects to health and wellbeing of people, pollutes the air, soil, and water, causes flooding, spreads diseases, harms flora and fauna, loss of money, and obstructs resource recovery. Therefore, Sri Lanka has been trying to find a long-lasting solution to MSWM, which should be environmentally, socially, and economically acceptable. Integrated Solid Waste Management (ISWM) provides a contemporary and systematic approach to MSWM. In these efforts, the paradigm shift from landfilling to MSW reduction or prevention is thought vital to be embedded. The government’s new policy on “Vistas of Prosperity and Splendor” and Draft National Environmental Policy (2021) also mandates the use of ISWM for MSWM in Sri Lanka. Embedding circular economy perspectives to ISWM further reduces the amount of MSW produced or retained globally by transforming it into resources. Therefore, the quantity of MSW disposed of at landfills is greatly reduced, and natural resources for manufacturing processes are optimized. This study focused on developing an ISWM framework for MSWM in Sri Lanka based on the circular economy perspectives and under the purview of the present administrative framework. The local needs and conditions were carefully analyzed during the study to determine the most suitable options for all aspects of MSWM, including generation, segregation, collection and transport, sorting, recovery, treatment, and final disposal of MSW. The application of the 3R concept for MSW minimization, promoting source-segregation, increasing the efficiency of collection and transport, producing value-added compost and liquid fertilizer, selling reuse and recyclable materials, pre-processing and reusing of construction and demolition waste, landfilling, and generating electricity through waste incineration were proposed under the ISWM framework developed. The value-addition to the final compost product and liquid fertilizer was considered mandatory, as the government has given priority to organic fertilizer production efforts. The proposed ISWM framework was applied to Kekirawa Pradeshiya Sabha to evaluate the long-term sustenance of the framework developed. The present status of MSWM practices carried out by Kekirawa Pradeshiya Sabha was evaluated through a questionnaire survey, field visits, meetings with officials involved in existing MSWM practices, and a comprehensive literature survey. Based on the deficiencies identified in the current MSWM practices carried out by Kekirawa Pradeshiya Sabha, the proposed ISWM framework developed was tailor-made to overcome the deficiencies identified and improve revenue generation to Kekirawa Pradeshiya Sabha. The current collection of MSW (17%) was increased up to 50% with the provision of two garbage compactors (6-8 m3 each). The open dumping of mixed waste currently being practiced will completely be halted, and an ISWM facility was designed with a compost plant, resource center, construction and demolition waste collection yard, and controlled landfill. The expected output of value-added compost and liquid fertilizers was 3.5 MT/day and 500 L/day, respectively. The electricity generation was 0.2 MW. Only 0.3 MT/day of fly ash will be disposed of in a secure landfill out of 13.8 MT/day of total MSW collected, which accounts iii for 1.3% of the total MSW generation. An economic analysis was carried out to evaluate the economic feasibility of the proposed ISMW framework for Kekirawa Pradeshiya Sabha. The results of economic analysis manifested that the Net Present Value (NPV) was SLR 66.52 million at an interest rate of 10%. The Internal Rate of Return (IRR) was 12%. Further, reduction of greenhouse gas emissions (GHG), land value appreciation, city beautification, improving health and wellbeing of people, promoting tourist attraction, and employment opportunities are other benefits to be gained from the proposed ISWM framework. Therefore, the proposed ISWM framework appears viable from a national economic viewpoint and can be used as a role model for the MSWM by other local authorities, particularly covering agriculture-based cities of Sri Lanka.