The effect of various environmental and design parameters on methane oxidation in a model biofilter

摘要

Methane from landfills built with RCRA (Resource Conservation and Recovery Act) covers is frequently vented directly to the atmosphere. Alternatively, landfill gasses could be vented through a layer of soil that could serve as a biofilter to oxidize CH_4 to carbon dioxide and water. Properly designed soil biofilters may reduce atmospheric CH_4 emissions from landfills and help reduce the accumulation of greenhouse gasses in the atmosphere. This study was conducted to investigate the performance of a lab-scale model biofilter system using soil as the filter-bed medium in packed columns to measure the effect of a variety of environmental and design factors on the CH_4 oxidation capacity of a soil biofilter. Biofilter performance was tested under a variety of environmental and design conditions. The optimum soil moisture content for CH_4 oxidation in a loamy sand was 13% by weight. Addition of NO_3-N did not affect the CH_4 oxidation rate. Soil depths of 30 cm and 60 cm were equally efficient in CH_4 oxidation. When the CH_4 loading rate was decreased, the percentage of CH_4 oxidized increased. The maximum CH_4 oxidation rate was 27.2 mol m~(-2) d~(-1) under optimum conditions.