عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The microbial reduction and precipitation of uranium using anaerobic bacteria are one of the effective methods considered during the last two decades to prevent permeation of the uranium to the environment. In this study, the capability of a facultative anaerobic bacterium, Shewanella spGCWx8, for reduction and removal of the uranium from the aqueous solutions are investigated. Thus, uranyl acetate is introduced into the bacteria anaerobically in the presence of the sodium lactate as an electron donor. This process resulted in the removal of the uranium from the solution and the formation of a precipitate containing uranium and cells. The analysis of the precipitate, using both Auto-lab and UV-vis spectra, confirmed that most of the uranium in the precipitate was in the from of reduced uranium, U(IV). Therefore, the mechanism of uranium removal by the strain GCWx8 in the aerobic condition is a reduction process. The best pH for a uranium removal by the GCWx8 was obtained 6.8, and the maximum removal percent at the cell density of 109 (cells per milliliter) has gained 90%. The first order of the reaction rate was satisfactory for bioreduction at the first day of the incubation. Based on the first order of the reaction rate assumption for the uranium bioreduction, the reaction rate constant was obtained 0.06 hr-1. As a result, strain Shewanella spGCWx8 was found as an able bacterium for the uranium bioreduction.
1. M. Benedict, T. H. Pigford, and H. W.Levi, Nuclear chemical engineering, 2nd ed. (McGraw-Hill, New York, 1981).
2. IAEA, Treatment of liquid effluent from uranium mines and mills during and after operation, (International Atomic Energy Agency, Vienna, Austria, 2004).
3. IAEA, Management of Radioactive Waste from the Mining and Milling of Uranium and Thorium Ores, (International Atomic Energy Agency, Vienna, Austria, 2002).
4. IAEA, Application of Membrane Technologies for Liquid Radioactive Waste Processing, (International Atomic Energy Agency, Vienna, Austria, 2004).
5. E. Zaki, Electrodialysis of uranium (VI) through cation exchange membranes and modeling of electrodialysis processes, J. Radioanal. Nucl. Chem. 252 (1), 21 (2002).
6. A. Zaheri, et al. Uranium separation from wastewater by electrodialysis, Iran. J. Environ. Health Sci. Eng. 7 (5), 423 (2010).
7. IAEA, Application of ion exchange processes for the treatment of radioactive waste and management of spent ion exchangers, (International Atomic Energy Agency, Vienna, Austria, 2002).
8. H. Tavakoli et al. Recovery of uranium from UCF liquid waste by anion exchange resin CG-400: breakthrough curves, elution behavior and modeling studies, Ann. Nucl. Energy 54, 149 (2013).
9. G. Seyrig, Uranium bioremediation: current knowledge and trends, Basic Biotechnol. 6, 19 (2010).
10. A. Zaheri, and A. R. Keshtkar, in: The Second Iran Membrane Conference, Selective Separation Of Uranium From UCF Effluents By Nanofiltration (Tehran, Iran, 2015).
11. B. Gu et al. Bioreduction of uranium in a contaminated soil column, Environ. Sci. Technol. 39 (13), 4841 (2005).
12. A. R. Keshtkar, M. Mohammadi, and M. A. Moosavian, Equilibrium biosorption studies of wastewater U(VI), Cu(II) and Ni(II) by the brown alga Cystoseira indica in single, binary and ternary metal systems, J. Radioanal. Nucl. Chem. 303 363 (2015).
13. D. R. Lovley, E. J. Phillips, Y. A. Gorby, and E. R. Landa, Microbial reduction of uranium, Nature 350, 413 (1991).
14. J. D. Wall, and L. R. Krumholz, Uranium reduction, Annu. Rev. Microbiol. 60, 149 (2006).
15. T. Tsuruta, Removal and recovery of uranium using microorganisms isolated from North American uranium deposits, Am. J. Environ. Sci. 3 (2), 60 (2007).
16. Y. Suzuki, and J. F. Banfield, Resistance to, and accumulation of, uranium by bacteria from a uranium-contaminated site, Geomicrobiol. J. 21 (2), 113 (2004).
17. T. Ohnuki et al. Interactions of uranium with bacteria and kaolinite clay, Chem. Geol. 220 (3), 237 (2005).
18. H. Golmohammadi, A. Rashidi,and S. J. Safdari, Prediction of ferric iron precipitation in bioleaching process using partial least squares and artificial neural network, Chem. Ind. Chem. Eng. Q. 19 (3), 321 (2013).
19. J. Istok et al. In situ bioreduction of technetium and uranium in a nitrate-contaminated aquifer, Environ. Sci. Technol. 38 (2), 468 (2004).
20. K. R. Czerwinski, and M. F. Polz, U.S. Patent No. 7.452.703 (18 Nov, 2008).
21. L. M.Mullen, PhD thesis, Cambridge, MA, 2007.
22. J. R. Haas, and A. Northup, Effects of aqueous complexation on reductive precipitation of uranium by Shewanella putrefaciens, Geochem. T. 5 (3), 41 (1999).
23. M. Truex et al. Kinetics of U(VI) reduction by a dissimilatory Fe(III)-reducing bacterium under nongrowth conditions, Biotechnol. Bioeng. 55, 490 (1997).
24. L. Sheng, J. Szymanowski, and J. B. Fein, The effects of uranium speciation on the rate of U(VI) reduction by Shewanella oneidensis MR-1, Geochim. Cosmochim. Ac. 75 3558 (2011).
25. A. S. Beliaev. MtrC, an outer membrane decahaem c cytochrome required for metal reduction in Shewanella putrefaciens MR‐1, Mol. Microbiol. 39 (3), 722 (2001).
26. M. J. Marshall. c-Type cytochrome-dependent formation of U (IV) nanoparticles by Shewanella oneidensis, PloS Biol. 4 (8), 1324 (2006).
27. W. D. Burgos. Characterization of uraninite nanoparticles produced by Shewanella oneidensis MR-1, Geochim. Cosmochim. Ac. 72 (20), 4901 (2008).
28. R. Hungate, A roll tube method for cultivation of strict anaerobes, Method. Microbiol. 3, 117 (1969).
29. O. Levenspiel, Chemical Reaction Engineering, (Wiley, New York, 1998).
30. W. Gao and A. J. Francis. Reduction of uranium (VI) to uranium (IV) by Clostridia, Appl. Environ. Microb. 74 (14), 4580 (2008).
31. S. K. Guin, A. S. Ambolikar, and J. V. Kamat, Electrochemistry of actinides on reduced graphene oxide: craving for the simultaneous voltammetric determination of uranium and plutonium in nuclear fuel, RSC Adv. 5, 59437 (2015).
32. R. B. Payne et al. Uranium reduction by Desulfovibrio desulfuricans strain G20 and a cytochrome c3 mutant, Appl. Environ. Microb. 68 (6), 3129 (2002).
33. J. R. Haas, T. J. Dichristina, and R. Wade, Thermodynamics of U (VI) sorption onto Shewanella putrefaciens, Chem. Geol. 180 (1), 33 (2001).
34. P. E. Long, Technical Basis for Assessing Uranium Bioremediation Performance, (U.S. Nuclear Regulatory Commission, Richland, WA, 2008).
35. Y. A. Gorby, and D. R. Lovley, Enzymatic uranium precipitation, Environ. Sci. Technol. 26 (1), 205 (1992).
36. S. M. Mousavi et al. Uranium recovery from UCF liquid waste by nanoporous MCM-41: breakthrough capacity and elution behavior studies, Res. Chem. Intermediat. 39, 951 (2013).
37. J.-H. Lee, and H.-G. Hur, Intracellular uranium accumulation by Shewanella sp. HN-41 under the thiosulfate-reducing condition, J. Korean Soc. Appl. Biol. Chem. 57 (1), 117 (2014).
38. D. L. Cologgi et al. Extracellular reduction of uranium via Geobacter conductive pili as a protective cellular mechanism, PNAS 108 (37), 15248 (2011).
39. Y. Suzuki, et al. Radionuclide contamination: Nanometre-size products of uranium bioreduction, Nature 419 (6903), 134 (2002).