Assessment of the methane oxidation capacity of soil

Methane oxidation capacity of three soil matrices was assessed using a new method based on the pressure fall resulting from methane oxidation. The effects of incubation temperature, moisture and methane content on the oxidation capacity were studied. Parameters observed were non-methanotrophic oxygen consumption, methane assimilation, length of the lag period before steady pressure fall was reached, initial pressure fall and maximum pressure fall. Filling material taken from a biofilter was tested. The length of the lag period was an index of prior exposure of the soil to methane emissions. Incubation temperature of 30degreesC and soil moisture at the water-holding capacity were chosen to standardize the test. Oxygen depletion by non-methanotrophs varied between 40 and 60% of the total oxygen consumption while methane assimilation was at 40 to 50% of the total methane consumption.