Short-term kinetic response of enhanced methane oxidation in landfill cover soils to environmental factors

This paper aims at a better understanding of methane oxidation under condit ions that are representative of landfill cover soils. The kinetics of metha ne oxidation were studied in landfill cover soils that had been exposed to high methane mixing ratios. This was done in batch experiments, under vario us environmental conditions. V-max increased exponentially with temperature in the range 5-35 degreesC, with a Q(10) value of 2.8. K-m increased appro ximately linearly in this range from 1.2 muM to 7 muM. Consequently, the in fluence of temperature on methane consumption was more pronounced at high c oncentrations than at low concentrations. The inhibition by ammonium of met hane consumption was much stronger after 6-7 months of exposure to high met hane mixing ratios than after 5-7 weeks of exposure, indicating that there was a shift of dominating methanotrophic species in soils after long exposu re times. Additions of nitrifying sludge or compost to soils initially inhi bited methane oxidation, followed by a stimulation after a few days.