Evaluation of methane oxidation efficiency in selected landfill soil cover / Mohd Suzairiff Zainal

Landfill is a source of anthropogenic CH4 and landfill soil cover has been considered as a potential medium to mitigate the gas emissions. This study investigated CH4 oxidation efficiency (MOE) in Jeram Sanitary Landfill soil cover at different moisture contents, organic matter contents and texture using column with 80cm soil thickness. MOE of MC15 (15% moisture content) was the highest (82%). Drier MC5 and wetter MC30 (5% and 30% moisture content, respectively) showed lower MOE (54% and 50%, respectively) due to the reduction of microbial activity and limited gas diffusion. The mixture of soil to coir pith at 30:70 (%v/v) (CP70) had enhanced the MOE up to 92%. At 50:50 (CP50) and 70:30 (CP30) of soil to coir pith, the mixtures scored 88 and 86% of MOE, respectively. The incorporation of coir pith to soil cover also enhanced MOE by increasing C:N and permeability of the soil. Meanwhile, sandy clay loam scored the highest MOE with 94% of MOE compared to clay loam (84%) and sandy loam (85%). It was proven that coarser texture of soil cover increased the soil breathability properties to enhance gas transportation along the soil thickness. Via Michaelis-Menten kinetics study, the value of maximum oxidation rate (Vmax) achieved by CP70 was higher (1.50ug g"1 h"1 ) compared to sandy clay loam and MC15 (1.20 and l.Olug g"1 h"1 , respectively). In conclusion, the data indicated modified soil cover with coir pith and sand achieved higher MOE compared to control soil.