Multiple lines of evidence identify U(V) as a key intermediate during U(VI) reduction by Shewanella oneidensis MR1

DOI: 10.1021/acs.est.9b05285

Authors: Gianni F. Vettese (The University of Manchester) , Katherine Morris (The University of Manchester) , Louise S. Natrajan (The University of Manchester) , Samuel Shaw (The University of Manchester) , Tonya Vitova (Karlsruhe Institute of Technology) , Jurij Galanzew (Karlsruhe Institute of Technology) , Debbie L. Jones (Bangor University) , Jonathan R. Lloyd (The University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Environmental Science & Technology

State: Published (Approved)
Published: January 2020
Diamond Proposal Number(s): 17243 , 13559

Abstract: As the dominant radionuclide by mass in many radioactive wastes, the control of uranium mobility in contaminated environments is of high concern. U speciation can be governed by microbial interactions, whereby metal-reducing bacteria are able to reduce soluble U(VI) to insoluble U(IV), providing a method for removal of U from contaminated groundwater. Although microbial U(VI) reduction is widely reported, the mechanism(s) for the transformation of U(VI) to poorly soluble U(IV) phases are poorly understood. By combining a suite of analyses, including luminescence, U M4-edge HERFD-XANES and U L3-edge XANES/EXAFS we show that the microbial reduction of U(VI) by the model Fe(III)-reducing bacterium, Shewanella oneidensis MR1, proceeds via a single electron transfer to form a pentavalent U(V) intermediate which disproportionates to form U(VI) and U(IV). Furthermore, we have identified significant U(V) present in post reduction solid phases, implying that U(V) may be stabilised for up to 120.5 hours.

Journal Keywords: Uranium; EXAFS; U(V); Shewanella oneidensis MR1; Bioreduction; Radwaste

Diamond Keywords: Bioremediation

Subject Areas: Chemistry, Environment


Instruments: B18-Core EXAFS

Added On: 20/01/2020 10:48

Documents:
gh5hhg444l.pdf

Discipline Tags:

Desertification & Pollution Earth Sciences & Environment Radioactive Materials Chemistry Materials Science Nuclear Waste

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)