Empirical gas emission and oxidation measurement at cover soil of dumping site: example from Malaysia

Methane (CH 4 ) is one of the most relevant greenhouse gases and it has a global warming potential 25 times greater than that of carbon dioxide (CO 2 ), risking human health and the environment. Microbial CH 4 oxidation in landfill cover soils may constitute a means of controlling CH 4 emissions. The study was intended to quantify CH 4 and CO 2 emissions rates at the Sungai Sedu open dumping landfill during the dry season, characterize their spatial and temporal variations, and measure the CH 4 oxidation associated with the landfill cover soil using a homemade static flux chamber. Concentrations of the gases were analyzed by a Micro-GC CP-4900. Two methods, kriging values and inverse distance weighting (IDW), were found almost identical. The findings of the proposed method show that the ratio of CH 4 to CO 2 emissions was 25.4 %, indicating higher CO 2 emissions than CH 4 emissions. Also, the average CH 4 oxidation in the landfill cover soil was 52.5 %. The CH 4 and CO 2 emissions did not show fixed-pattern temporal variation based on daytime measurements. Statistically, a negative relationship was found between CH 4 emissions and oxidation ( R 2 = 0.46). It can be concluded that the variation in the CH 4 oxidation was mainly attributed to the properties of the landfill cover soil.