Landfill methane oxidation across climate types in the U.S.
Methane oxidation in landfill covers was determined by stable isotope analyses over 37 seasonal sampling events at 20 landfills with intermediate covers over four years. Values were calculated two ways: by assuming no isotopic fractionation during gas transport, which produces a conservative or minimum estimate, and by assuming limited isotopic fractionation with gas transport producing a higher estimate. Thus bracketed, the best assessment of mean oxidation within the soil covers from chamber captured emitted CH(4) was 37.5 ± 3.5%. The fraction of CH(4) oxidized refers to the fraction of CH(4) delivered to the base of the cover that was oxidized to CO(2) and partitioned to microbial biomass instead of being emitted to the atmosphere as CH(4) expressed as a percentage. Air samples were also collected at the surface of the landfill, and represent CH(4) from soil, from leaking infrastructure, and from cover defects. A similar assessment of this data set yields 36.1 ± 7.2% oxidation. Landfills in five climate types were investigated. The fraction oxidized in arid sites was significantly greater than oxidation in mediterranean sites, or cool and warm continental sites. Sub tropical sites had significantly lower CH(4) oxidation than the other types of sites. This relationship may be explained by the observed inverse relationship between cover loading and fractional CH(4) oxidation.
Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida, USA. jchanton@fsu.edu
Jeffrey
J
Chanton
Tarek
T
Abichou
Claire
C
Langford
Gary
G
Hater
Roger
R
Green
Doug
D
Goldsmith
Nathan
N
Swan
D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry*; D000397:Air Pollution / Q000706:statistics & numerical data; D002247:Carbon Isotopes; D005591:Chemical Fractionation; D002980:Climate; D004784:Environmental Monitoring; D008697:Methane / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D012037:Refuse Disposal; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry; D014481:United States
D000393:Air Pollutants; D002247:Carbon Isotopes; D012989:Soil Pollutants; D008697:Methane