SELECTION AND EVALUATION OF A FEASIBLE INTEGRATED DISPOSAL FACILITY FOR MANAGING MUNICIPAL SOLID WASTE (NEW) IN THE WESTERN PROVINCE OF SRI LANKA

摘要

The present dumpsite to the entrance of the Colombo, the commercial capital of Sri Lanka, is more than 30m high and it poses a real danger to the City. Remaining available land for a solid waste management project is in the buffer zone of a conserved wetland. Use of this land for a suitable project would be a sustainable solution compared to losing an estimated extent of 50 acres of wetlands each year by unauthorized dumping. ' Landfill Cell Bioreactors' have been chosen as one of the technologies, since it could be implemented in a short period of time to satisfy the authorities. The reported time duration for peak generation of gases is approximately two years and varies between five to seven years to complete the entire cycle. The research conducted in the tropics indicates shorter time for completing the cycle with the novel approach of circulating the leachate from one cell to another. Furthermore, exposing the leachate to aerobic conditions before recycling spoils the buffer capacity of the system. Mining the wastes and loading the Inclined Step Grate ( ISG) composting system will create thermophilic conditions to produce sanitary compost. The ISG complements RDF production for the Waste to Energy Plant. The integrated system is feasible with a predicted IRR of 25% and a payback period of 5 years.