Remediation of uranium contaminated soils with bicarbonate extraction and microbial U(VI) reduction
- 435 Downloads
A process for concentrating uranium from contaminated soils in which the uranium is first extracted with bicarbonate and then the extracted uranium is precipitated with U(VI)-reducing microorganisms was evaluated for a variety of uranuum-contaminated soils. Bicarbonate (100 mM) extracted 20–94% of the uranium that was extracted with nitric acid. The U(VI)-reducing microorganism,Desulfovibrio desulfuricans reduced the U(VI) to U(IV) in the bicarbonate extracts. In some instances unidentified dissolved extracted components, presumably organics, gave the extract a yellow color and inhibited U(VI) reduction and/or the precipitation of U(IV). Removal of the dissolved yellow material with the addition of hydrogen peroxide alleviated this inhibition. These results demonstrate that bicarbonate extraction of uranium from soil followed by microbial U(VI) reduction might be an effective mechanism for concentrating uranium from some contaminated soils.
Key wordsBioremediation Uranium Mill tailings Desulfovibrio
Unable to display preview. Download preview PDF.
- 1.Allison, L.E. and C.D. Moody, 1965. In: Methods of Soil Analysis. Part 2. Chemical and Microbiological Properties (Black, C.A., ed.), pp. 1379–1396, American Society of Agronomy. Madison, WI.Google Scholar
- 2.Cox, C.H. and W.J. Roushey. 1979. Recovery of uranium by in situ solution mining. Min. Indust. Bull. 22: 1–12.Google Scholar
- 3.Ebinger, M.H., E.H. Essington, E.S. Gladney, B.D. Newman and C. Reynolds. 1993. Redistribution of depleted uranium (DU) in soils and water at two US Army proving grounds. Ann. Meet. Health Phys. Soc. Absts. 64: S60.Google Scholar
- 4.Gorby, Y.A. and D.R. Lovley. 1992. Enzymatic uranium precipitation. Environ. Sci. Technol. 26: 205–207.Google Scholar
- 5.Landa, E.R. 1982. Leaching of radionuclides from uranium ore and mill tailings. Uranium 1: 53–64.Google Scholar
- 8.Lovley, D.R. and E.J.P. Phillips. 1992. Bioremediation of uranium contamination with enzymatic uranium reduction. Eviron. Sci. Technol. 26: 2228–2234.Google Scholar
- 10.Lovley, D.R., E.J.P. Phillips, Y.A. Gorby and E.R. Landa. 1991. Microbial reduction of uranium. Nature 350: 413–416.Google Scholar
- 11.Lovley, D.R., E.E. Roden, E.J.P. Phillips and J.C. Woodward. 1993. Enzymatic iron and uranium reduction by sulfate-reducing bacteria. Marine Geol. 113: 41–53.Google Scholar
- 13.Osiensky, J.L. and R.E. Williams. 1990. Factors affecting efficient aquifer restoration at in situ uranium mine sites. Ground Wat. Mont Rev. 10: 107–112.Google Scholar
- 14.Sheppard, S.C. and W.G. Evenden. 1992. Bioavailability indices for uranium: effect of concentration in eleven soils. Arch. Environ. Contam. Toxicol. 23: 117–124.Google Scholar