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

dc.contributor.authorMtimunye, Phalazane Johanna
dc.contributor.authorChirwa, Evans M.N.
dc.date.accessioned2018-08-24T12:47:18Z
dc.date.available2018-08-24T12:47:18Z
dc.date.issued2018
dc.description.abstractNuclear 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.departmentChemical Engineeringen_ZA
dc.description.librarianam2018en_ZA
dc.description.sponsorshipThe 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.urihttp://www.aidic.it/ceten_ZA
dc.identifier.citationMtimunye 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.issn2283-9216 (online)
dc.identifier.other10.3303/CET1864089
dc.identifier.urihttp://hdl.handle.net/2263/66333
dc.language.isoenen_ZA
dc.publisherThe Italian Association of Chemical Engineeringen_ZA
dc.rights© 2018, AIDIC Servizi S.r.l.en_ZA
dc.subjectEffluentsen_ZA
dc.subjectRemoval efficienciesen_ZA
dc.subjectRadioactive waste treatment systemen_ZA
dc.subjectNuclear fuel processingen_ZA
dc.subjectIndustrial activitiesen_ZA
dc.subjectElectricity generationen_ZA
dc.subjectContinuous flow reactorsen_ZA
dc.subjectBioremediation technologiesen_ZA
dc.subjectAlternative energy sourceen_ZA
dc.subjectWastewater treatmenten_ZA
dc.subjectWastewater disposalen_ZA
dc.subjectWaste treatmenten_ZA
dc.subjectSolutionsen_ZA
dc.subjectRadioactivityen_ZA
dc.subjectRadioactive wastesen_ZA
dc.subjectOrganic carbonen_ZA
dc.subjectFossil fuelsen_ZA
dc.subjectFossil fuel power plantsen_ZA
dc.subjectBiotechnologyen_ZA
dc.subjectBioremediationen_ZA
dc.subjectBioreactorsen_ZA
dc.subjectBiofilmsen_ZA
dc.subjectBioconversionen_ZA
dc.subjectBacteriaen_ZA
dc.titleBiological U(VI) reduction in a fixed-bed bioreactor using radiotoxic tolerant mixed-culture of bacteriaen_ZA
dc.typeArticleen_ZA

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Mtimunye_Biological_2018.pdf
Size:
604.47 KB
Format:
Adobe Portable Document Format
Description:
Article

License bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
1.75 KB
Format:
Item-specific license agreed upon to submission
Description: