Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions

This research pertains to bioleaching of copper containing ores with particular reference to the copper sulfide mineral chalcopyrite (CuFeS2). While it is focused on heap bioleaching, it has applications to stirred tank bioleaching operations. In the context of bioleaching, microbial extra-cellular...

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Bibliographic Details
Main Author: Africa, Cindy-Jade
Other Authors: Harrison, Susan T L
Format: Doctoral Thesis
Language:English
Published: University of Cape Town 2017
Subjects:
Online Access:http://hdl.handle.net/11427/25001
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spelling ndltd-netd.ac.za-oai-union.ndltd.org-uct-oai-localhost-11427-250012021-01-25T05:11:31Z Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions Africa, Cindy-Jade Harrison, Susan T L Van Hille, Robert P Bioprocess Engineering This research pertains to bioleaching of copper containing ores with particular reference to the copper sulfide mineral chalcopyrite (CuFeS2). While it is focused on heap bioleaching, it has applications to stirred tank bioleaching operations. In the context of bioleaching, microbial extra-cellular polymeric substance (EPS) components are thought to complex chemical oxidants and extend the chemical reaction space available for mineral dissolution reactions, making the microbial-mineral-EPS interface the dominant active zone in terms of microbial oxidation and mineral dissolution. There is a limited understanding of microbial biofilm formation within a bioleach heap. The implication of various microorganisms having a set of defined or optimal conditions under which they colonise and proliferate is quite substantial. Understanding what creates favourable interfacial microenvironments enabling a sessile population to flourish (and thereby decrease lag time) has great implications for minimising costs and maximising productivity. Furthermore, limited work has been conducted on thermophilic microorganisms relevant to bioleaching. These microorganisms are pertinent to successful bioleaching at high temperatures, with work incorporating low grade ores and gangue mineralogy also being scarce. The aim of this research is to provide a thorough investigation into microbial-metal sulfide interfacial environments in situ, using a thermophilic archaeon M. hakonensis, low-grade metal-sulfide ores, a series of temperature regimes, heap-simulating conditions and an in depth extraction and analysis of the EPS produced under varied culturing conditions. 2017-08-28T13:14:54Z 2017-08-28T13:14:54Z 2017 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/25001 eng application/pdf University of Cape Town Faculty of Engineering and the Built Environment Centre for Bioprocess Engineering Research
collection NDLTD
language English
format Doctoral Thesis
sources NDLTD
topic Bioprocess Engineering
spellingShingle Bioprocess Engineering
Africa, Cindy-Jade
Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
description This research pertains to bioleaching of copper containing ores with particular reference to the copper sulfide mineral chalcopyrite (CuFeS2). While it is focused on heap bioleaching, it has applications to stirred tank bioleaching operations. In the context of bioleaching, microbial extra-cellular polymeric substance (EPS) components are thought to complex chemical oxidants and extend the chemical reaction space available for mineral dissolution reactions, making the microbial-mineral-EPS interface the dominant active zone in terms of microbial oxidation and mineral dissolution. There is a limited understanding of microbial biofilm formation within a bioleach heap. The implication of various microorganisms having a set of defined or optimal conditions under which they colonise and proliferate is quite substantial. Understanding what creates favourable interfacial microenvironments enabling a sessile population to flourish (and thereby decrease lag time) has great implications for minimising costs and maximising productivity. Furthermore, limited work has been conducted on thermophilic microorganisms relevant to bioleaching. These microorganisms are pertinent to successful bioleaching at high temperatures, with work incorporating low grade ores and gangue mineralogy also being scarce. The aim of this research is to provide a thorough investigation into microbial-metal sulfide interfacial environments in situ, using a thermophilic archaeon M. hakonensis, low-grade metal-sulfide ores, a series of temperature regimes, heap-simulating conditions and an in depth extraction and analysis of the EPS produced under varied culturing conditions.
author2 Harrison, Susan T L
author_facet Harrison, Susan T L
Africa, Cindy-Jade
author Africa, Cindy-Jade
author_sort Africa, Cindy-Jade
title Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
title_short Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
title_full Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
title_fullStr Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
title_full_unstemmed Investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
title_sort investigation of microbial metal-sulfide interfacial environments under mineral bioleach simulated conditions
publisher University of Cape Town
publishDate 2017
url http://hdl.handle.net/11427/25001
work_keys_str_mv AT africacindyjade investigationofmicrobialmetalsulfideinterfacialenvironmentsundermineralbioleachsimulatedconditions
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