Quantifying methane oxidation from landfills using stable isotope analysis of downwind plumes
Landfills are major contributors to the atmospheric CH{sub 4} budget. A major uncertainty in estimating CH{sub 4} emission by methanotrophic bacteria in the aerobic outer portions of the cover soil. These bacteria intercept the gas as it migrates toward the atmosphere. To estimate cover soil oxidation, the authors made seasonal measurements of the difference in the {delta}{sup 13}C of CH{sub 4} within the anoxic zone and CH{sub 4} released from landfills and captured downwind at two landfills in the Northeastern US. Anoxic zone CH{sub 4} at the Nashua Landfill averaged -54.6 {+-} 0.7{per{underscore}thousand}, n = 205, and displayed no significant seasonal pattern. Methane was in excess over ambient air concentrations in the downwind plume ranging from 2.13 to 3.41 ppmv. The {delta}{sup 13}C of excess CH{sub 4}, as determined by mass balance with correction for ambient air CH{sub 4}, varied from -49.35 to -54.28{per{underscore}thousand}. The authors used these values to calculate soil CH{sub 4} oxidation, which ranged from 0 to 23.6%. Oxidation was greatest in the summer and in the fall, with an annual value of 12 {+-} 8%. At a second landfill, plume CH{sub 4} ranged from 1.96 to 2.92 ppmv with excess {delta}{sup 13}C values of {minus}52.17 to {minus}58.06{per{underscore}thousand}. Oxidation at this landfill ranged from 0 to 14%.
- Research Organization:
- Florida State Univ., Tallahassee, FL (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FC03-90ER61010
- OSTI ID:
- 20000699
- Journal Information:
- Environmental Science and Technology, Vol. 33, Issue 21; Other Information: PBD: 1 Nov 1999; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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