title: A fully coupled model for water-gas-heat reactive transport with methane oxidation in landfill covers.
abstract: Methane oxidation in landfill covers is a complex process involving water, gas and heat transfer as well as microbial oxidation. The coupled phenomena of microbial oxidation, water, gas, and heat transfer are not fully understood. In this study, a new model is developed that incorporates water-gas-heat coupled reactive transport in unsaturated soil with methane oxidation. Effects of microbial oxidation-generated water and heat are included. The model is calibrated using published data from a laboratory soil column test. Moreover, a series of parametric studies are carried out to investigate the influence of microbial oxidation-generated water and heat, initial water content on methane oxidation efficiency. Computed and measured results of gas concentration and methane oxidation rate are consistent. It is found that the coupling effects between water-gas-heat transfer and methane oxidation are significant. Ignoring microbial oxidation-generated water and heat can result in a significant difference in methane oxidation efficiency by 100%.
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Electronic address: cecwwng@ust.hk.
authors.forename: C W W
authors.initials: CW
authors.lastname: Ng
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Electronic address: sfengaa@ust.hk.
authors.forename: S
authors.initials: S
authors.lastname: Feng
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Electronic address: hliuan@ust.hk.
authors.forename: H W
authors.initials: HW
authors.lastname: Liu
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring; D006358:Hot Temperature; D008697:Methane / Q000032:analysis*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D012037:Refuse Disposal / Q000379:methods*; D064091:Waste Disposal Facilities
chemical_list: D000393:Air Pollutants; D008697:Methane
keywords: Methane oxidation; Reactive transport; Simulation; Water–gas–heat coupled