|De visscher, Alex|
Submitted to: Waste Management and Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/27/2009
Publication Date: 8/1/2009
Publication URL: http://handle.nal.usda.gov/10113/59597
Citation: Scheutz, C., Kjeldsen, P., Bogner, J.E., De Visscher, A., Gebert, J., Hilger, H.A., Huber-Humer, M., Spokas, K.A. 2009. Microbial Methane Oxidation Processes and Technologies for Mitigation of Landfill Gas Emissions. Waste Management and Research. 27(5):409-455. Interpretive Summary: Landfill gas is produced by microbial anaerobic degradation of the organic fraction in waste disposed of in landfill facilities. The organic material in waste includes paper, animal and vegetable matter and garden waste. The main components in landfill gas are methane (55-60%v/v) and carbon dioxide (40-45%v/v). Methane is a strong greenhouse gas and landfills are one of the major anthropogenic sources to methane in the atmosphere. Landfill methane may be oxidized by methanotrophic microorganisms in soils or waste materials covering landfills utilizing the oxygen, which is diffusing into the cover layer from the atmosphere. The methane oxidation process, which is governed by several environmental factors, can be exploited in engineered facilities established for methane emission mitigation. Mathematical models can be used to predict methane emissions from landfills taking into account methane oxidation. This review will summarize the current literature covering methane oxidation microbiology, engineering, modeling and assessment from landfills. There are still lessons to be learned before methane mitigation technologies based on the microbial methane oxidation process are fully established. However, these engineered systems will have applications beyond landfill environments where mitigation of methane emissions are desired (i.e. livestock manure management).
Technical Abstract: The aim of this paper is to review the present knowledge regarding the microbial methane oxidation in natural or engineered landfill environments with focus on process understanding, engineering experiences and modeling. This review includes seven sections. First, the methane oxidation is put in context with other processes governing the fate of methane in landfills by introduction of the methane mass balance approach. The important groups of microbes involved in the microbial methane oxidation are described next, followed by a detailed overview of the oxidation process in soils and waste materials including the factors controlling the oxidation rate. Hereafter, experiences with engineered systems for mitigating landfill methane emissions relying on microbial CH4 oxidation are presented. The next section reviews measured gas emissions at landfills including the methodologies used for measuring emissions. The last two sections describe models; the first section reviews mass balance models used for estimating landfill gas emissions for national greenhouse gas inventories, while the last section goes into the details of mathematical models of the transport processes in soil covers including the oxidation process.