Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Electrical Resistivity Imaging For Long-Term Autonomous Monitoring Of Hydrocarbon Degradation: Lessons From The Deepwater Horizon Oil Spill, Jeffrey W. Heenan, Lee D. Slater, Dimitrios Ntarlagiannis, Estella A. Atekwana, Babu Z. Fathepure, Sonal Dalvi, Cameron Ross, D. Dale Werkema, Eliot A. Atekwana
Electrical Resistivity Imaging For Long-Term Autonomous Monitoring Of Hydrocarbon Degradation: Lessons From The Deepwater Horizon Oil Spill, Jeffrey W. Heenan, Lee D. Slater, Dimitrios Ntarlagiannis, Estella A. Atekwana, Babu Z. Fathepure, Sonal Dalvi, Cameron Ross, D. Dale Werkema, Eliot A. Atekwana
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Conceptual models for the geophysical responses associated with hydrocarbon degradation suggest that the long-term evolution of an oil plume will result in a more conductive anomaly than the initial contamination. In response to the Deepwater Horizon (DH) oil spill into the Gulf of Mexico in 2010, an autonomous resistivity monitoring system was deployed on Grand Terre, Louisiana, in an attempt to monitor natural degradation processes in hydrocarbon-impacted beach sediments of this island. A 48-electrode surface array with a 0.5-m spacing was installed to obtain twice-daily images of the resistivity structure of the shallow subsurface impacted by oil. Over the course …
Temporal Geophysical Signatures From Contaminant-Mass Remediation, Vukenkeng Che-Alota, Estella A. Atekwana, Eliot A. Atekwana, William August Sauck, D. Dale Werkema
Temporal Geophysical Signatures From Contaminant-Mass Remediation, Vukenkeng Che-Alota, Estella A. Atekwana, Eliot A. Atekwana, William August Sauck, D. Dale Werkema
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
We have previously documented changes in bulk electrical conductivity, self-potential (SP), and ground-penetrating-radar (GPR) reflections in a field setting caused by biogeochemical transformations of hydrocarbon-contaminated media. These transformations are associated with hydrocarbon biodegradation. The results of surface geophysical surveys acquired in 1996, 2003, and 2007 document changes in geophysical signatures associated with removing hydrocarbon mass in the contaminated zone. Initial investigations in 1996 showed that relative to background, the contaminated area was characterized by higher bulk electrical conductivity, positive SP anomaly, and attenuated GPR reflections. Repeated surveys in 2003 and 2007 over the contaminated area showed that in 2007, the …
The Microbial Community Structure In Petroleum-Contaminated Sediments Corresponds To Geophysical Signatures, Jonathan P. Allen, Estella A. Atekwana, Eliot A. Atekwana, Joseph W. Duris, D. Dale Werkema, Silvia Rossbach
The Microbial Community Structure In Petroleum-Contaminated Sediments Corresponds To Geophysical Signatures, Jonathan P. Allen, Estella A. Atekwana, Eliot A. Atekwana, Joseph W. Duris, D. Dale Werkema, Silvia Rossbach
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
The interdependence between geoelectrical signatures at underground petroleum plumes and the structures of subsurface microbial communities was investigated. For sediments contaminated with light non-aqueous-phase liquids, anomalous high conductivity values have been observed. Vertical changes in the geoelectrical properties of the sediments were concomitant with significant changes in the microbial community structures as determined by the construction and evaluation of 16S rRNA gene libraries. DNA sequencing of clones from four 16S rRNA gene libraries from different depths of a contaminated field site and two libraries from an uncontaminated background site revealed spatial heterogeneity in the microbial community structures. Correspondence analysis showed …
Induced-Polarization Measurements On Unconsolidated Sediments From A Site Of Active Hydrocarbon Biodegradation, Gamal Z. Abdel Aal, Lee D. Slater, Estella A. Atekwana
Induced-Polarization Measurements On Unconsolidated Sediments From A Site Of Active Hydrocarbon Biodegradation, Gamal Z. Abdel Aal, Lee D. Slater, Estella A. Atekwana
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
To investigate the potential role that indigenous microorganisms and microbial processes may play in altering low frequency electrical properties, induced-polarization (IP) measurements in the frequency range of 0.1 to 1000 Hz were acquired from sediment samples retrieved from a site contaminated by hydrocarbon undergoing intrinsic biodegradation. Increased imaginary conductivity and phase were observed for samples from the smear zone (contaminated with residual-phase hydrocarbon), exceeding values obtained for samples contaminated with dissolved-phase hydrocarbons, and in turn, exceeding values obtained for uncontaminated samples. Real conductivity, although generally elevated for samples from the smear zone, did not show a strong correlation with contamination. …
Investigating The Geoelectrical Response Of Hydrocarbon Contamination Undergoing Biodegradation, D. Dale Werkema, Estella A. Atekwana, Anthony L. Endres, William August Sauck, Daniel P. Cassidy
Investigating The Geoelectrical Response Of Hydrocarbon Contamination Undergoing Biodegradation, D. Dale Werkema, Estella A. Atekwana, Anthony L. Endres, William August Sauck, Daniel P. Cassidy
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
A newly proposed geoelectrical model for hydrocarbon contaminated sites predicts high conductivities coincident with the contaminated zone as opposed to the traditionally accepted low conductivity. The model attributes the high conductivities to mineral weathering resulting from byproducts of microbial redox processes. To evaluate this conductive model, in situ vertical conductivity measurements were acquired from a light non-aqueous phase liquid (LNAPL) contaminated site. The results showed high conductivities coincident with the zone of contamination and within the smear zone influenced by seasonal water table fluctuations. We infer this zone as an active zone of biodegradation and suggest significant microbial degradation under …