Gradient packing bed bio-filter for landfill methane mitigation.

We assessed the suitability of various biogenic materials for development of a gradient packed bed bio-filter to mitigate the methane (CH 4 ) emission from landfills. Five different biogenic materials (windrow compost-WC; vermicompost-VC; landfill top cover-LTC; landfill bottom soil-LBS; and river soil sediment-SS) were screened. Among these materials, the VC showed a better CH 4 oxidation potential (MOP) of 12.6 μg CH 4 g dw −1 h −1 . Subsequently, the VC was used as a packing material along with wood chips in proto-type bio-filters. Wood chips were mixed at 5–15% to form three distinct gradients in a test bio-filter. Under the three different CH 4 loading rates of 33, 44 and 55 gCH 4 m −3 h −1 , the achieved MOPs were 31, 41, and 47gCH 4 m −3 h −1 , respectively. The gradient packed bed bio-filter is effective for landfill CH 4 mitigation than the conventional bio-filter as the latter shows gas channeling effects with poor MOPs. [ABSTRACT FROM AUTHOR]