Effects of Compost Thickness and Compaction on Methane Emissions in Simulated Landfills

As a product from municipal solid waste treatment, compost is sometimes cannot be utilized as organic fertilizer because its raw material has been contaminated from the start. One particular alternative solution for compost is to use it as landfill biocover. This solution is not only for controlling CH4 emissions but also reducing the need for soil cover. This study aimed to determine the methane concentration profile within reactors by utilizing compost produced by the City of Depok Composting Unit. Results showed that the methane concentration decreased when the thickness of the media was increased. Additionally, the concentration of carbon dioxide tended to increase the concentration in the upper layers of the media. High levels of compaction caused the maximum methane oxidation zone to shift to the bottom of the reactor. This could be seen in the reactor with a compaction rate of 800-900 kg/m3, where the maximum methane oxidation zone was at a depth of more than 62 cm from reactor's media surface. The reactor with a compaction rate of 750 kg/m3 had a maximum methane oxidation zone at a depth of 20-30 cm from the reactor's media surface. An enhanced compost maturation phase is also necessary to optimize the use of compost as a landfill biocover.