Biogeochemical Controls on Technetium Mobility in Biogeochemical Controls on Technetium Mobility in FRC Sediments
Technetium-99 is a priority pollutant at numerous DOE sites, due to its long half-life (2.1 x 10{sup 5} years), high mobility as Tc(VII) in oxic waters, and bioavailability as a sulfate analog. {sup 99}Tc is far less mobile under anaerobic conditions, forming insoluble Tc(IV) precipitates. As anaerobic microorganisms can reduce soluble Tc(VII) to insoluble Tc(IV), microbial metabolism may have the potential to treat sediments and waters contaminated with Tc. Baseline studies of fundamental mechanisms of Tc(VII) bioreduction and precipitation (reviewed by Lloyd et al, 2002) have generally used pure cultures of metal-reducing bacteria, in order to develop conceptual models for the biogeochemical cycling of Tc. There is, however, comparatively little known about interactions of metal-reducing bacteria with environmentally relevant trace concentrations of Tc, against a more complex biogeochemical background provided by mixed microbial communities in the subsurface. The objective of this new NABIR project is to probe the site specific biogeochemical conditions that control the mobility of Tc at the FRC (Oak Ridge, TN). This information is required for the rational design of in situ bioremediation strategies for technetium-contaminated subsurface environments. We will use a combination of geochemical, mineralogical, microbiological and spectroscopic techniques to determine the solubility and phase associations of Tc in FRC sediments, and characterize the underpinning biogeochemical controls. A key strength of this project is that many of the techniques we are using have already been optimized by our research team, who are also studying the biogeochemical controls on Tc mobility in marine and freshwater sediments in the UK in a NERC funded companion study.
- Research Organization:
- University of Manchester, UK; University of Leeds, UK
- Sponsoring Organization:
- USDOE Office of Science (SC)
- OSTI ID:
- 895388
- Report Number(s):
- CONF-NABIR2004-35; TRN: US0700455
- Resource Relation:
- Conference: Annual NABIR PI Meeting, March 15-17, 2004, Warrenton, VA
- Country of Publication:
- United States
- Language:
- English
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Novel imaging techniques, integrated with mineralogical, geochemical and microbiological characterizations to determine the biogeochemical controls on technetium mobility in FRC sediments
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Related Subjects
54 ENVIRONMENTAL SCIENCES
59 BASIC BIOLOGICAL SCIENCES
ANAEROBIC CONDITIONS
BACTERIA
BIOREMEDIATION
COMMUNITIES
DESIGN
HALF-LIFE
METABOLISM
MICROORGANISMS
POLLUTANTS
PRECIPITATION
PROBES
SEDIMENTS
SOLUBILITY
SULFATES
TECHNETIUM
TECHNETIUM 99