The removal behavior of U(VI) by Shewanella putrefaciens was investigated in this study. Our results demonstrated the formation of uranium phosphate biomineral, predominantly existed as chernikovite [H2(UO2)2(PO4)2·8H2O], on the cell surface of S. putrefaciens. The lamellar chernikovite was found at slightly acid pH, but not at pH > 7.0. Phosphate-containing groups played the key role in the formation of chernikovite based on the analysis of IR. After ashing and hydrothermal process, bacterially mediated chernikovite can be transformed into inorganic uranium phosphate and UO2, respectively. The findings can provide a potential strategy for in situ bioremediation of uranium in aerobic environment.
Graphical abstract
Biomineralization process of uranium on S. putrefaciens.