Abstract：Batch tests with a duration up to 22 days were carried out on the loess samples to measure their methane oxidation capacity. Some loess samples were taken from the temporary covers with different durations of placement at Xi'an landfill, the others were produced by mixing fresh loess with different content of compost. The influence of moisture content on methane oxidation was also investigated. The relationships among the volume changes of different gas compositions during methane oxidation process were analyzed. The experiments demonstrated that the methane oxidation capacity of the covering loess depended significantly on the duration of placement on the landfill. The maximum methane oxidation capacity ranged from 26.05 to 53.95μg CH4/(g×h) for the temporary cover loess with a placement duration in between 3 and 5 years. The fresh loess had no methane oxidation capacity within 22 days of incubation. The admixture of fresh loess with compost significantly enhanced the methane oxidation capacity of the loess. When the compost content was less than 50%, the maximum methane oxidation capacity of loess increased linearly with an increase in the compost content. The moisture content of loess had a significant influence on the methane oxidation, and the optimum moisture content of loess for methane oxidation is 20% ~ 30%. During the methane oxidation process, about 44% of carbon in CH4 was oxidized to CO2, the rest carbon was converted to intracellular substances. In the design of a landfill final cover, the required methane oxidation capacity as well as the required compost addition should be determined according to the CH4 generation from the landfill and the gas permeability of the landfill cover.
