Author

Allen

Date of Award

8-2006

Degree Name

Master of Science

Department

Biological Sciences

First Advisor

Dr. Silvia Rossbach

Second Advisor

Dr. Estella Atekwana

Third Advisor

Dr. Todd Barkman

Fourth Advisor

Dr. Steven Kohler

Access Setting

Masters Thesis-Open Access

Abstract

Petroleum contamination of sediments leads to dynamic changes in the subsurface. These include changes in the microbiota as well as in the subsurface geophysical and geochemical properties. Anomalously high conductivity values observed in subsurface zones contaminated with light non aqueous phase liquids (LNAPLs) have been suggested to be the result of microbial activity. Therefore, we investigated the interdependence between geoelectrical signatures and microbial community structure in petroleum contaminated field sediments and laboratory column experiments. Spatial and temporal changes in electrical conductivity of the subsurface paralleled changes in microbial community composition, with the highest conductivity values concomitant with specific anaerobic hydrocarbon-degrading populations. We surmise that with an abundant carbon source such as petroleum hydrocarbons, increased microbial activity results in the physical and chemical alteration of the immediate environment, effectively changing the subsurface geophysical properties within those zones. We suggest that geoelectrical measurements are an efficient tool to guide sampling for microbial ecology studies during the monitoring of natural or engineered bioremediation projects.

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Biology Commons

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