Numerical simulation of dynamic processes of the methane migration and oxidation in landfill cover

The coupling model of the multicomponent gas flow and transport was developed to describe methane oxidation in landfill cover. A two-part simulation was carried out to investigate the dynamic processes of methane oxidation. The reliability of the coupling model was validated by comparing the simulated data on gas concentrations with the measured data. To evaluate the influence of the pumping well on the oxidation reaction, methane emission throughout the landfill cover was simulated. Methane oxidation in the landfill cover demonstrated dynamic characteristics. The results suggest that the oxidation effect is closely related to methane emission. Sensitivity parameters were also introduced to determine the maximum oxidation rate and permeability. The critical targets of the reduction rate and reduction volume of methane were analyzed based on 20 years' worth of pumping operation data. The result further illustrates the dynamic behavior of methane oxidation, which is influenced by the degree of methanotrophic reaction and the balance between methane and air influx in the landfill cover. The results highlight the significance of the study in quantitatively assessing the capacity of landfill covers to reduce methane emissions in landfills. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1419–1424, 2014