MONITORING MUNICIPAL SOLID WASTE LEACHATE MOBILITY THROUGH SOIL AND COMPOST

Abstract

Municipal solid waste produces leachate that contains huge amount of organic carbon, metals, and nutrients. These contaminants deteriorate receiving environment. The harmful affect of waste can only be reduced by keeping the leachate emissions in control. We checked the feasibility of a bioretention media (compost) that could be used to underline the waste to reduce the contaminant leaching from waste. Two experiments were conducted to analyze compost as an adsorbent that can be used as a soil amendment to reduce the contaminant discharge from the waste. In the first experiment, leachate from three organic streams was characterized, followed by two leaching experiments with an objective of evaluating compost, and amended compost as a retention media. Leachate generated by the organic streams of municipal solid waste contained many times higher contaminant levels than the environmental quality standards. The results from compost leaching experiments showed that compost may not be used directly as an adsorption media because compost itself produced substantial amount of contaminants. The contaminant concentrations remained high through out the experimental period, which is equal to a flux of 144 m. The biochar amendment did not improve the contaminant mobility from the compost, instead the biochar amendment increased the particulate and dissolved organic carbon concentrations. Sand + compost remained the most efficient mixture among all the amendments for the retention of contaminants.