title: Geophysical Monitoring of Hydrocarbon-Contaminated Soils Remediated with a Bioelectrochemical System.
abstract: Efficient noninvasive techniques are desired for monitoring the remediation process of contaminated soils. We applied the direct current resistivity technique to image conductivity changes in sandbox experiments where two sandy and clayey soils were initially contaminated with diesel hydrocarbon. The experiments were conducted over a 230 day period. The removal of hydrocarbon was enhanced by a bioelectrochemical system (BES) and the electrical potentials of the BES reactors were also monitored during the course of the experiment. We found that the variation in electrical conductivity shown in the tomograms correlate well with diesel removal from the sandy soil, but this is not the case with the clayey soil. The clayey soil is characterized by a larger specific surface area and therefore a larger surface conductivity. In sandy soil, the removal of the diesel and products from degradation leads to an increase in electrical conductivity during the first 69 days. This is expected since diesel is electrically insulating. For both soils, the activity of BES reactors is moderately imaged by the inverted conductivity tomogram of the reactor. An increase in current production by electrochemically active bacteria activity corresponds to an increase in conductivity of the reactor.
authors.affiliation: Colorado School of Mines, Department of Geophysics, Golden, 80401, Colorado United States.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Mao
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
authors.affiliation: ISTerre, CNRS, UMR CNRS 5275, Université de Savoie, 73376 cedex, Le Bourget du Lac, France.
authors.forename: André
authors.initials: A
authors.lastname: Revil
authors.affiliation: Chevron Energy Technology Company, San Ramon, California 94583, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: Colorado School of Mines, Department of Geophysics, Golden, 80401, Colorado United States.
authors.forename: John
authors.initials: J
authors.lastname: Hinton
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.
authors.forename: Zhiyong Jason
authors.initials: ZJ
authors.lastname: Ren
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D004787:Environmental Pollution; D006838:Hydrocarbons / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D006838:Hydrocarbons; D012987:Soil; D012989:Soil Pollutants