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Microbial ecology of a crude oil contaminated aquifer

January 1, 2002

Detailed microbial analyses of a glacial outwash aquifer contaminated by crude oil provide insights into the pattern of microbial succession from iron reducing to methanogenic in the anaerobic portion of the contaminant plume. We analysed sediments from this area for populations of aerobes, iron reducers, fermenters and methanogens, using the most probable number method. On the basis of the microbial data the anaerobic area can be divided into distinct physiological zones dominated by either iron-reducers or a consortium of fermenters and methanogens. Chemistry and permeability data show that methanogenic conditions develop first in areas of high hydrocarbon flux. Thus, we find methanogens both in high permeability horizons and also where separate-phase crude oil is present in either the saturated or unsaturated zone. Microbial numbers peak at the top of the separate-phase oil suggesting that growth is most rapid in locations with access to both hydrocarbons and nutrients infiltrating from the surface.

Publication Year 2002
Title Microbial ecology of a crude oil contaminated aquifer
Authors B.A. Bekins, I.M. Cozzarelli, E. Warren, E.M. Godsy
Publication Type Article
Publication Subtype Journal Article
Series Title IAHS-AISH Publication
Index ID 70025078
Record Source USGS Publications Warehouse