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 30 degrees C 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.