Quantifying methane oxidation in a landfill-cover soil by gas push-pull tests

Journal Article · Tue Sep 15 04:00:00 EDT 2009 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2009.05.011· OSTI ID:21269364

Gonzalez-Gil, G; Lazzaro, A ^[1]

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1. Institute of Biogeochemistry and Pollutant Dynamics, ETH Zuerich, Universitaetstrasse 16, 8092 Zuerich (Switzerland)

Methane (CH{sub 4}) oxidation by aerobic methanotrophs in landfill-cover soils decreases emissions of landfill-produced CH{sub 4} to the atmosphere. To quantify in situ rates of CH{sub 4} oxidation we performed five gas push-pull tests (GPPTs) at each of two locations in the cover soil of the Lindenstock landfill (Liestal, Switzerland) over a 4 week period. GPPTs consist of the injection of a gas mixture containing CH{sub 4}, O{sub 2} and noble gas tracers followed by extraction from the same location. Quantification of first-order rate constants was based upon comparison of breakthrough curves of CH{sub 4} with either Ar or CH{sub 4} itself from a subsequent inactive GPPT containing acetylene as an inhibitor of CH{sub 4} oxidation. The maximum calculated first-order rate constant was 24.8 {+-} 0.8 h{sup -1} at location 1 and 18.9 {+-} 0.6 h{sup -1} at location 2. In general, location 2 had higher background CH{sub 4} concentrations in vertical profile samples than location 1. High background CH{sub 4} concentrations in the cover soil during some experiments adversely affected GPPT breakthrough curves and data interpretation. Real-time PCR verified the presence of a large population of methanotrophs at the two GPPT locations and comparison of stable carbon isotope fractionation of CH{sub 4} in an active GPPT and a subsequent inactive GPPT confirmed that microbial activity was responsible for the CH{sub 4} oxidation. The GPPT was shown to be a useful tool to reproducibly estimate in situ rates of CH{sub 4} oxidation in a landfill-cover soil when background CH{sub 4} concentrations were low.

• OSTI ID: 21269364
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 9 Vol. 29; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACETYLENE
CARBON ISOTOPES
EMISSION
METHANE
OXIDATION
RARE GASES
REACTION KINETICS
SANITARY LANDFILLS
WASTES