Application of leachate recirculation on the concentration of landfill gases

Abstract

Leachate is the product of the biodegradation process in the landfill. On-site treatment of leachate using leachate recirculation is one of the alternative methods to reduce the hazard. The operation of leachate recirculation provides benefits such as speeding up biodegradation, lowering pollutant concentrations, and increasing gas production. This study aims to evaluate the application of leachate recirculation on the concentration of CO2 and CH4 produced. Experiments were performed in a laboratory using 20 lysimeters, with 1 L in volume for 365 days. The lysimeter was divided into two groups, with 10 reactors, each group arranged in series. Leachate recirculation will be given to the second reactor until the tenth reactor, using a high leachate concentration for the first group and a low concentration of leachate for the second. The addition of leachate in the two reactor treatment groups significantly increased the organic content in the leachate. Leachate recirculation does not cause a significant escalation in CO2 and CH4 concentration compared to reactors without leachate recirculation. In the reactor group with high leachate concentrations, reactors with leachate recirculation produced a more stable gas concentration than those without leachate recirculation which produced more volatile CH4 concentration.