Microbial Reductive Transformation of Phyllosilicate Fe(III) and U(VI) in Fluvial Subsurface Sediments

Journal Article · Wed Mar 14 04:00:00 EDT 2012 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es204528m· OSTI ID:1057820

Lee, Ji-Hoon ^[1]; Fredrickson, Jim K. ^[1]; Kukkadapu, Ravi K. ^[1]; Boyanov, Maxim I. ^[2]; Kemner, Kenneth M. ^[2]; Lin, Xueju ^[1]; Kennedy, David W. ^[1]; Bjornstad, Bruce N. ^[1]; Konopka, Allan ^[1]; Moore, Dean A. ^[1]; Resch, Charles T. ^[1]; Phillips, Jerry L. ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. Argonne National Lab. (ANL), Argonne, IL (United States)

The microbial reduction of Fe(III) and U(VI) were investigated in shallow aquifer sediments collected from subsurface Pleistocene flood deposits near the Hanford Reach of the Columbia River in Washington State. Increases in 0.5 N HCl-extractable Fe(II) were observed in incubated sediments and 57Fe Mössbauer spectroscopy revealed that Fe(III) associated with phyllosilicates and pyroxene was reduced to Fe(II). Aqueous uranium(VI) concentrations decreased in incubated Hanford sediments with the rate and extent being greater in sediment amended with organic carbon. X-ray absorption spectroscopy of bioreduced sediments indicated that 67-77% of the U signal was U(VI), probably as an adsorbed species associated with a new or modified reactive mineral phase. Phylotypes within the Deltaproteobacteria were more common in Hanford sediments incubated with U(VI) than without and in U(VI)-free incubations, members of the Clostridiales were dominant with sulfate-reducing phylotypes more common in the sulfate-amended sediments. These results demonstrate the potential for anaerobic reduction phyllosilicate Fe(III) and sulfate in Hanford unconfined aquifer sediments and biotransformations involving reduction and adsorption leading to decreased aqueous U concentrations.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1057820
• Report Number(s): PNNL-SA--79333; 42318; 34494; KP1702030
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 7 Vol. 46; ISSN 0013-936X
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

300 Area
Environmental Molecular Sciences Laboratory
Hanford
biogeochemical
terminal electron accepting