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You searched for subject:(Indigenous mine consortium). Showing records 1 – 2 of 2 total matches.

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University of Pretoria

1. Chabalala, Simphiwe. Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium.

Degree: Chemical Engineering, 2011, University of Pretoria

The utilisation of fossil fuels for energy worldwide depletes the natural reserves and at the same time releases billions of tonnes of carbon dioxide and other greenhouse gases into the atmosphere. In order to reverse the negative effects of this accumulation, i.e., global warming and climatic changes, countries around the world are now considering nuclear energy and other cleaner sources of energy as a substitute to the burning of fossil fuels. The deployment of the later technology has progressed slowly due to lack of public support. The general public and environmental lobbyists worry about the discharge of radioactive waste from nuclear power generation and accidents that have occurred in the nuclear power industry in the recent past. One of pollutants of concern is uranium which is discharged from the nuclear generation processes as the highly toxic uranium-6, (U(VI)). U(VI) coming from the reactors is radioactive as well as highly toxic to aquatic life forms. Biological treatment of metal pollutants is viewed as an environmentally friendly alternative to conventional physical/chemical treatment methods, especially in dilute solutions where physical/chemical methods may not be effective. Microbial processes may be applied both as in situ and/or ex situ processes. Microbial consortia, consisting of several species of microorganisms in the form of bioflocs for reducing/removing the pollutants have been used as they preserve the complex interrelationships that exist between species in the source. The results of this study demonstrate the potential of microbial U(VI) reduction as a possible replacement technology for physical/chemical processes currently in use in the nuclear industry. A detailed analysis of the biological reduction of uranium-(VI) was conducted and the following were the main findings of the study: (1) Background uranium concentration in soil from the mine was determined to be 168 mg/kg, a very high value compared to the typical concentration of uranium in natural soils; (2) Among six bacteria species isolated from a uranium mine in Limpopo, South Africa, three anaerobic species – Pantoea sp., Enterobacter sp. and Pseudomonas stutzeri – reduced U(VI) to U(VI) and facilitated the removal of the uranium species from solution. Based on batch studies and cell disruption studies, the laws governing microbial U(VI) reduction were determined and the kinetic parameters for U(VI) reduction were determined. The cultures in this study reduced uranium-U(VI) at a rate better than rates found in literature for other microorganisms. Reduction rates reported in this paper can be used to assess the applicability of bioreduction for uranium removal processes. Advisors/Committee Members: Prof E M N Chirwa (advisor).

Subjects/Keywords: Indigenous mine consortium; Uranium-(vi); Nuclear energy; Microaerobic; UCTD

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chabalala, S. (2011). Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/28129

Chicago Manual of Style (16th Edition):

Chabalala, Simphiwe. “Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium.” 2011. Masters Thesis, University of Pretoria. Accessed November 22, 2019. http://hdl.handle.net/2263/28129.

MLA Handbook (7th Edition):

Chabalala, Simphiwe. “Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium.” 2011. Web. 22 Nov 2019.

Vancouver:

Chabalala S. Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium. [Internet] [Masters thesis]. University of Pretoria; 2011. [cited 2019 Nov 22]. Available from: http://hdl.handle.net/2263/28129.

Council of Science Editors:

Chabalala S. Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium. [Masters Thesis]. University of Pretoria; 2011. Available from: http://hdl.handle.net/2263/28129


University of Pretoria

2. [No author]. Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium .

Degree: 2011, University of Pretoria

The utilisation of fossil fuels for energy worldwide depletes the natural reserves and at the same time releases billions of tonnes of carbon dioxide and other greenhouse gases into the atmosphere. In order to reverse the negative effects of this accumulation, i.e., global warming and climatic changes, countries around the world are now considering nuclear energy and other cleaner sources of energy as a substitute to the burning of fossil fuels. The deployment of the later technology has progressed slowly due to lack of public support. The general public and environmental lobbyists worry about the discharge of radioactive waste from nuclear power generation and accidents that have occurred in the nuclear power industry in the recent past. One of pollutants of concern is uranium which is discharged from the nuclear generation processes as the highly toxic uranium-6, (U(VI)). U(VI) coming from the reactors is radioactive as well as highly toxic to aquatic life forms. Biological treatment of metal pollutants is viewed as an environmentally friendly alternative to conventional physical/chemical treatment methods, especially in dilute solutions where physical/chemical methods may not be effective. Microbial processes may be applied both as in situ and/or ex situ processes. Microbial consortia, consisting of several species of microorganisms in the form of bioflocs for reducing/removing the pollutants have been used as they preserve the complex interrelationships that exist between species in the source. The results of this study demonstrate the potential of microbial U(VI) reduction as a possible replacement technology for physical/chemical processes currently in use in the nuclear industry. A detailed analysis of the biological reduction of uranium-(VI) was conducted and the following were the main findings of the study: (1) Background uranium concentration in soil from the mine was determined to be 168 mg/kg, a very high value compared to the typical concentration of uranium in natural soils; (2) Among six bacteria species isolated from a uranium mine in Limpopo, South Africa, three anaerobic species – Pantoea sp., Enterobacter sp. and Pseudomonas stutzeri – reduced U(VI) to U(VI) and facilitated the removal of the uranium species from solution. Based on batch studies and cell disruption studies, the laws governing microbial U(VI) reduction were determined and the kinetic parameters for U(VI) reduction were determined. The cultures in this study reduced uranium-U(VI) at a rate better than rates found in literature for other microorganisms. Reduction rates reported in this paper can be used to assess the applicability of bioreduction for uranium removal processes. Advisors/Committee Members: Prof E M N Chirwa (advisor).

Subjects/Keywords: Indigenous mine consortium; Uranium-(vi); Nuclear energy; Microaerobic; UCTD

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

author], [. (2011). Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium . (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-09222011-102801/

Chicago Manual of Style (16th Edition):

author], [No. “Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium .” 2011. Masters Thesis, University of Pretoria. Accessed November 22, 2019. http://upetd.up.ac.za/thesis/available/etd-09222011-102801/.

MLA Handbook (7th Edition):

author], [No. “Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium .” 2011. Web. 22 Nov 2019.

Vancouver:

author] [. Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium . [Internet] [Masters thesis]. University of Pretoria; 2011. [cited 2019 Nov 22]. Available from: http://upetd.up.ac.za/thesis/available/etd-09222011-102801/.

Council of Science Editors:

author] [. Reduction of uranium-(VI) under microaerobic conditions using an indigenous mine consortium . [Masters Thesis]. University of Pretoria; 2011. Available from: http://upetd.up.ac.za/thesis/available/etd-09222011-102801/

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