The Methane Removal Efficiency in Biochar-Methanotroph-Clay Landfill Cover

The landfill is one of the main sources of methane emissions. The landfill cover is at the top of the landfill as an important solution to reduce methane. In this study, biochar and methanotroph amendment to clay are proposed to create a new landfill cover soil, biochar-methanotroph-clay (BMC) mixture, because biochar and methanotroph have the functions of absorbing and oxidizing methane respectively. Adopting chemical oxidation aging method, water film transfer method and other methods, a total of 48 groups of experiments were conducted to stimulate the effects of biochar content, oxidation aging times and methane-filled days to the methane removal efficiency of BMC. The results indicated that the methane removal efficiency increased first and then decreased with the increase of biochar content; it increased gradually with the increase of aging times and methane-filled days. After 6 times of oxidation aging and 30 days of breeding methanotrophs, the BMC with 5% biochar content showed the highest methane removal capacity amounting to 14.05mg/g, which is more than twice the number of the clay.