Methane production during the anaerobic decomposition of composted and raw organic refuse in simulated landfill cells

Abstract

Methane contributes 20% annually to increases in global warming, and is explosive at concentrations of 5-15% in air. Landfills contribute 15% to total methane emissions. This study was conducted to determine the potential decrease in methane production from landfills if organic waste is composted prior to. The quantities and rates of methane production were measured from simulated landfill cells containing composted and raw simulated refuse. The refuse was composted in an open pile and characterized by temperature, pH, ash content and C02 evolved during aerobic respiration. Assuming a 1 0% lignin content, the labile carbon fraction was reduced by an estimated 71 % during composting. Over a of six month period, simulated landfill cells filled with raw waste generated 66 M3 methane per Mg of dry refuse, while cells containing compost produced 31 M3 methane per Mg of dry compost. Per unit weight of dry raw material, composted waste placed in a landfill produced only 23% of the methane that was generated from raw refuse.