Numerical Model for Biological Oxidation and Migration of Methane in Soils

Abstract

Concern over the potentially negative impacts of climate change has resulted in a search for techniques to reduce anthropogenic emissions of methane, a primary greenhouse gas. Microbial oxidation of methane in soils may serve as an inexpensive technique for reducing CH4 emissions from sources such as landfills and heavy oil wells. To gain a better quantitative understanding of the biological and physical processes limiting CH4 oxidation in soils and biofilters, a numerical reactive-transport model was developed. The model inputs include CH4 source strength, soil bulk density, moisture content, and biological kinetic parameters. The outputs consist of gas concentration profiles, CH4 oxidation rates, and surface flux rates. A series of soil column and batch incubation experiments were performed on a variety of soil types to calibrate and verify the model. The model was also verified by reproducing experimental results found in the literature.