Estimation of mass transport parameters of gases for quantifying CH{sub 4} oxidation in landfill soil covers
- Department of Civil and Environmental Engineering, College of Engineering, Seoul National University, Seoul (Korea, Republic of)
Methane (CH{sub 4}), which is one of the most abundant anthropogenic greenhouse gases, is produced from landfills. CH{sub 4} is biologically oxidized to carbon dioxide, which has a lower global warming potential than methane, when it passes through a cover soil. In order to quantify the amount of CH{sub 4} oxidized in a landfill cover soil, a soil column test, a diffusion cell test, and a mathematical model analysis were carried out. In the column test, maximum oxidation rates of CH{sub 4} (V{sub max}) showed higher values in the upper part of the column than those in the lower part caused by the penetration of O{sub 2} from the top. The organic matter content in the upper area was also higher due to the active microbial growth. The dispersion analysis results for O{sub 2} and CH{sub 4} in the column are counter-intuitive. As the upward flow rate of the landfill gas increased, the dispersion coefficient of CH{sub 4} slightly increased, possibly due to the effect of mechanical dispersion. On the other hand, as the upward flow rate of the landfill gas increased, the dispersion coefficient of O{sub 2} decreased. It is possible that the diffusion of gases in porous media is influenced by the counter-directional flow rate. Further analysis of other gases in the column, N{sub 2} and CO{sub 2}, may be required to support this hypothesis, but in this paper we propose the possibility that the simulations using the diffusion coefficient of O{sub 2} under the natural condition may overestimate the penetration of O{sub 2} into the soil cover layer and consequently overestimate the oxidation of CH{sub 4}.
- OSTI ID:
- 21217142
- Journal Information:
- Waste Management, Vol. 29, Issue 2; Other Information: DOI: 10.1016/j.wasman.2008.07.006; PII: S0956-053X(08)00238-9; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0956-053X
- Country of Publication:
- United States
- Language:
- English
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