Reoxidation of Biogenic Reduced Uranium: A Challenge Toward Bioremediation

Date

2014-01-01

Author

Singh, Gursharan
Şengör, Sema Sevinç
Bhalla, Aditya
Kumar, Sudhir
De, Jaysankar
Stewart, Brandy
Spycher, Nicolas
Ginn, Timothy M.
Peyton, Brent M.
Sani, Rajesh K.

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Uraninite (UO2) is the most desirable end product of in situ bioreduction because of its low solubility under reducing conditions. For effective long-term immobilization of uranium (U), there should be no biotic or abiotic reoxidation of the insoluble biogenic U(IV). It is therefore critical to understand the long-term stability of U(IV) under oxic- and nutrient-limited conditions at U-contaminated subsurface sites. It has now been established that following in situ bioremediation of U(VI) via nutrient addition in the subsurface, a range of physical, chemical, and biological factors control the rate and extent of long-term stability of U(IV). Some of these factors are tied to site specific conditions including existence of oxidants such as Fe(III)(hydr)oxides, Mn(IV) oxides, oxygen, and nitrate; the presence of organic carbon and the reduced forms of U (e.g., mononuclear U(IV) or nanometer-sized uraninite particles); and the carbonate concentration and pH of groundwater. This review analyzes the contribution of these factors in controlling U(IV)-reoxidation, and highlights the competition among U(IV) and other electron acceptors and possible mechanisms of reoxidation of various forms of U(IV).

URI

https://hdl.handle.net/11511/94021

Journal

CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY

DOI

https://doi.org/10.1080/10643389.2012.728522

Collections

Department of Environmental Engineering, Article

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Citation Formats

G. Singh et al., “Reoxidation of Biogenic Reduced Uranium: A Challenge Toward Bioremediation,” CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, vol. 44, no. 4, pp. 391–415, 2014, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/94021.