Relating groundwater and sediment chemistry to microbial characterization at a BTEX-contaminated site

Conference · Mon Jul 01 04:00:00 EDT 1996

OSTI ID:251608

Pfiffner, S M; Palumbo, A V; McCarthy, J F ^[1]; Gibson, T ^[2]

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1. Oak Ridge National Lab., TN (United States)
2. General Motors Research and Development Center, Warren, MI (United States); and others

The National Center for Manufacturing Science is investigating bioremediation of petroleum hydrocarbon at a site in Belleville, Michigan. As part of this study we examined the microbial communities to help elucidate biodegradative processes currently active at the site. We observed high densities of aerobic hydrocarbon degraders and denitrifiers in the less-contaminated sediments. Low densities of iron and sulfate reducers were measured in the same sediments. In contrast, the highly-contaminated sediments showed low densities of aerobic hydrocarbon degraders and denitrifiers and high densities of iron and sulfate reducers. Methanogens were also found in these highly-contaminated sediments. These contaminated sediments also showed a higher biomass, by phospholipid fatty acids, and greater ratios of phospholipid fatty acids which indicate stress within the microbial community. Aquifer chemistry analyses indicated that the more-contaminated area was more reduced and had lower sulfate than the less-contaminated area. These conditions suggest that the subsurface environment at the highly-contaminated area had progressed into sulfate reduction and methanogensis. The less-contaminated area, although less reduced, also appeared to be progressing into primarily iron- and sulfate-reducing microbial communities. The proposed treatment to stimulate bioremediation includes addition of oxygen and nitrate. Groundwater chemistry and microbial analyses revealed significant differences resulted from the injection of dissolved oxygen and nitrate in the subsurface. These differences included increases in pH and Eh and large decreases in BTEX, dissolved iron, and sulfate concentrations at the injection well.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 251608
• Report Number(s): CONF-960539--2; ON: DE96012081
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
55 BIOLOGY AND MEDICINE
BASIC STUDIES
CONTAMINATION
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
GROUND WATER
HYDROCARBONS
MICROORGANISMS
NITRATES
REMEDIAL ACTION