Biological U(VI) reduction in a fixed-bed bioreactor using radiotoxic tolerant mixed-culture of bacteria

Show simple item record Mtimunye, Phalazane Johanna Chirwa, Evans M.N. 2018-08-24T12:47:18Z 2018-08-24T12:47:18Z 2018
dc.description.abstract Nuclear energy has been proposed as an alternative energy source in the bid to reduce carbon emissions that results from fossil fuel. Hexavalent uranium [U(VI)] is the most abandoned radioactive waste discharged from nuclear fuel processing, electricity generation power plants, radioisotope manufacturing plants. Improper disposal or storage of U(VI) containing waste may poses a threat to aquatic systems and related ecological systems. Treatment of U(VI) containing effluents from these industrial activities requires the reduction of highly mobile and radiotoxic U(VI) to tetravalent U(IV) which readily forms the hydroxide precipitate [U(OH)4(s)] under neutral pH conditions. Processes employing biofilm and fixed-film systems for treatment of wastewater are considered more robust than planktonic culture systems in the presence of high toxicity, and therefore, are preferred in the treatment of toxic liquid waste. In this study U(VI) reduction is investigated using a fixed-film reactor inoculated with U(VI) reducing bacteria isolated from tailing dump soil collected from an abandoned uranium mine in South Africa. The fixed-film bioreactor was operated as a continuous flow reactor under oxygen stressed conditions without the addition of external organic carbon source. The results from this study showed that the fixed-bed bioreactor was able to achieve >90 % U(VI) removal efficiency at U(VI) concentration of up to 85 mg/L, concentration which is higher than that observed at the study site. This demonstrates the feasibility of the fixed-bed bioreactor in continuously removing U(VI) in aqueous solutions without the need of introducing external organic carbon source and without re-seeding the bioreactor. The bioremediation technology proposed in this study significantly demonstrated the effectiveness of the biofilm processes in treating process effluent streams and U(VI) contaminated sites as part of the pump-and treat. Fundamental understanding of uranium-bacteria interactions taking place in a complex biofilm structure under such conditions would be effective in developing an appropriate radioactive waste treatment system for the subsurface bioremediation process. en_ZA
dc.description.department Chemical Engineering en_ZA
dc.description.librarian am2018 en_ZA
dc.description.sponsorship The South African National Research Foundation (NRF) National Research Foundation (NRF) through the NRF Competitive Programme for Rated Researchers Grant No. CPR20110603000019146 and the NRF Incentive Finding for Rated Researchers (IFRR) Grant No. IFR2010042900080 awarded to Evans M. N. Chirwa of the University of Pretoria and Sasol South Africa (Pty) Ltd through the student bursary Grant No. PIF-Ref: 525/08-14 awarded to Phalazane J. Mtimunye at the University of Pretoria. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Mtimunye P.J., Chirwa E., 2018, Biological u(vi) reduction in a fixed-bed bioreactor using radiotoxic tolerant mixed-culture of bacteria, Chemical Engineering Transactions, 64, 529-534, DOI: 10.3303/CET1864089. en_ZA
dc.identifier.issn 2283-9216 (online)
dc.identifier.other 10.3303/CET1864089
dc.language.iso en en_ZA
dc.publisher The Italian Association of Chemical Engineering en_ZA
dc.rights © 2018, AIDIC Servizi S.r.l. en_ZA
dc.subject Effluents en_ZA
dc.subject Removal efficiencies en_ZA
dc.subject Radioactive waste treatment system en_ZA
dc.subject Nuclear fuel processing en_ZA
dc.subject Industrial activities en_ZA
dc.subject Electricity generation en_ZA
dc.subject Continuous flow reactors en_ZA
dc.subject Bioremediation technologies en_ZA
dc.subject Alternative energy source en_ZA
dc.subject Wastewater treatment en_ZA
dc.subject Wastewater disposal en_ZA
dc.subject Waste treatment en_ZA
dc.subject Solutions en_ZA
dc.subject Radioactivity en_ZA
dc.subject Radioactive wastes en_ZA
dc.subject Organic carbon en_ZA
dc.subject Fossil fuels en_ZA
dc.subject Fossil fuel power plants en_ZA
dc.subject Biotechnology en_ZA
dc.subject Bioremediation en_ZA
dc.subject Bioreactors en_ZA
dc.subject Biofilms en_ZA
dc.subject Bioconversion en_ZA
dc.subject Bacteria en_ZA
dc.title Biological U(VI) reduction in a fixed-bed bioreactor using radiotoxic tolerant mixed-culture of bacteria en_ZA
dc.type Article en_ZA

Files in this item

This item appears in the following Collection(s)

Show simple item record