Effect of leachate recirculation on refuse decomposition rates at landfill site: a case study

In this study, a comparison of methane (CH₄) generation rates for two test cells, one operated with (enhanced) and another without leachate recirculation at Odayeri Sanitary Landfill were compared using their bio-chemical methane potentials (BMP). Initial methane potential is approximately 34.5 m3 CH₄/wet ton of solid waste. The remaining methane potential for the control (C1) and the enhanced (C2) cells are 32.6 m3 CH₄/wet ton and 31.1 m3 CH₄/wet ton of refuse after eight months of operation, respectively. The produced CH₄ quantities for C1 and C2 after eight months of operation are 1.9 m3 CH₄/wet ton and 3.4 m3 CH₄/wet ton, respectively. On the other hand, 5.5% and 9.9% of the total potential are generated in eight months. However, the CH₄ generation rates for the first year are determined as 2.85 and 5.10 m3/ton/year for C1 and C2 test cells, respectively. Due to the appropriate conditions such as moisture content, solid waste decomposition rate is enhanced at a rate of 79% at C2 test cell relative to C1 test cell. Hence, C2 test cell shows more decomposition relative to the C1 test cell.