Comparison of solid waste stabilization and methane emission from anaerobic and semi-aerobic landfills operated in tropical condition

Abstract

Leachate quality and methane emission from pilot-scale lysimeters operated under semi-aerobic and anaerobic conditions were monitored for 650 days. Two semi-aerobic lysimeters were filled with un-compacted and compacted municipal solid wastes whereas two anaerobic lysimeters containing compacted wastes were operated with leachate storage at 50% and 100% of waste height, respectively. Despite having high moisture in wastes and operating under tropical rainfall events, leachate stabilization in semi-aerobic lysimeters took place much faster resulting in BOD reduction by 90% within 60 days, significantly shorter than 180–210 days observed in anaerobic lysimeters. Nitrogen concentration in leachate from semi-aerobic lysimeter could be reduced by 90%. In term of gas emission, semi-aerobic lysimeter with un-compacted wastes had much lower methane emission rate of 2.8 g/m2/day compare to anaerobic lysimeters (62.6 g/m2/day) through seasonal fluctuation was observed. Nevertheless, semi-aerobic lysimeter with waste compaction has similar performance to anaerobic lysimeter.