Radiocarbon and Stable Carbon Isotope Analysis to Confirm Petroleum Natural Attenuation in the Vadose Zone
Title:
Radiocarbon and Stable Carbon Isotope Analysis to Confirm Petroleum Natural Attenuation in the Vadose Zone
Author:
Coffin, Richard B. Pohlman, John W. Grabowski, Kenneth S. Knies, David. L. Plummer, Rebecca E. Magee, Robert W. Boyd, Thomas J.
Appeared in:
Environmental forensics
Paging:
Volume 9 (2008) nr. 1 pages 75-84
Year:
2008-01
Contents:
CO2 and CH4 radiocarbon and stable carbon isotope ratios were used to assess natural attenuation at a fuel-contaminated soil site at the Norfolk Navy Base, Norfolk, VA (USA). Soil gas samples were collected spatially over a monitoring network in October 2002 and in March 2003. CO2 and CH4 from regions with high petroleum concentrations were 14C-depleted relative to uncontaminated areas. 14C-depleted methane suggested methanogenic hydrocarbon degradation. The difference in CO2 age between background and plume-influenced areas indicated that approximately 90% of the CO2 at the latter was petroleum derived, making contaminant the primary source of carbon for the microbial assemblage.