Influence of biological pre-treatment of municipal solid waste on landfill behaviour in Sri Lanka.

Sri Lanka is an island in the Indian Ocean with an area about 65 610 km(2). The population of the country is around 20.2 million. Hazardous disposal of municipal solid waste (MSW) is a major concern particularly in the most urbanized areas of Sri Lanka. However, the current waste management system does not facilitate any waste pre-treatment techniques before final disposal. As a consequence, there is immense pressure to improve the waste disposal practices in the country. Under the above circumstance, this study is an attempt to examine the influence of biological pre-treatment of MSW on landfill behaviour in Sri Lanka. Field-scale lysimeters with untreated and biologically pre-treated MSW were used for this study. The data was obtained on leachate quantity, quality, and settlement. The ambient parameters were also measured at the experiment site. According to the results, the effect of rainfall incident on leachate generation was visible but the effect on pre-treated waste was comparatively less than untreated waste. The organic pollutant load in leachate of pre-treated MSW was seven times lower than that of untreated MSW. The settlement of the lysimeter with pre-treated MSW was comparatively less. It can be concluded that the process of biological pre-treatment of MSW by composting is an effective method for Sri Lanka and also it reduces the health and environmental risks by improving the behaviour of landfill.