Impact of Nickel (Ni) and Uranium (U) on Microorganisms
at Steeds Pond, Savannah River Site
This project is a collaboration with the laboratory of Dr. Paul Bertsch at the Savannah River Ecology Laboratory of the University of Georgia. The focus of our studies is on Steed Pond, a uranium and nickel contaminated area of the Savannah River Site. Our studies are focused on the following areas:
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the impact of U and Ni availability on microorganisms/microbial communities capable of trichloroethylene (TCE) degradation |
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the influence of pH on the toxicity of U and Ni to micoorganisms |
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the use of hydroxyapatite to sequester U and Ni, thus reducing their toxicity and enhancing remediation potential of co-contaminants organics |
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Joy Van Nostrand, US EPA STAR Fellow conducts research on the microbial toxicity of U and Ni, and the impact of pH on toxicity. Her work suggests that nickel, and other divalent cations, are more toxic at a pH of 7 than a pH of 5. Collaborative modeling studies with Drs. Andrew Sowder and Paul Bertsch (Savannah River Ecology Laboratory) suggest that this is not due to speciation. On-going studies are addressing whether the microbial metal resistance mechanisms are more effective at lower pH values. |
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Dr. Andrew Sowder, Visiting Scientist from the Savannah River Ecology Laboratory, is studying how uranium and nickel speciation influences their bioavailability in riparian sediments. |
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Dr. Tanya Khijniak, a postdoctoral fellow in the laboratory, studied four Ni resistant Gram-positive microorganisms that she has isolated from Steeds Pond at the Savannah River Site (Aiken, SC). In addition, she is studying the ability of hydroxyapatite (HA) to sequester U and Ni, therefore reducing their microbial toxicity. |
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