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Sustainable landfilling in Asia |
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University of Padua IMAGE Department |
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The design of a sustainable landfill in an Asian should incorporate (Hogland W. et al., 2005): • A liner system at the base and sides of the landfill to prevent migration of leachate or gas to the surrounding environment • Leachate and gas collection, together with treatment systems to meet regulatory requirements • Final cover of the landfill that enhances surface drainage, prevents infiltration of water and supports surface vegetation • Surface water drainage system that collects and removes surface run-off from the site • Environmental monitoring system that periodically collects and analyses air, surface water, soil and ground water samples around the landfill site. The waste should be treated within the lifetime of each generation and remaining residues should be stabilized under environmental safe conditions. To achieve this under Asian conditions it requires a controlled breakdown of the biodegradabile fraction to accelerate the degradation process and increase the efficiency in which the dry tomb concept is transformed to a landfill bioreactor. The leachate is collected and recycled in the anaerobic bioreactor and stabilized within less than 10 years. The amount of methane generated in this type of bioreactor is directly related to the amount of organic material in the waste stream diverted to the reactor. The sustainable landfill combines the principles of bioreactor landfill to enhance the process of stabilization and landfill mining to recover the space for reuse while salvaging decomposed organic matter for agricultiral use. In addition, pre-treatment of MSW prior to landfill through aerobic processing, anaerobic digestion or a combination of both should be adopted in Asia. This would reduce the total amount of waste to be disposed off and simultaneously diminish the need for leachate treatment and landfill gas management, geotechnical problems due to landfill settlements, and the lenght of the altercare period. Compaction and appropriate cover would reduce the risk of waste spreading. |