The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes

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dc.contributor.advisorLiesegang, E Cen_ZA
dc.contributor.authorCostello, John Anthonyen_ZA
dc.date.accessioned2015-01-27T10:05:04Z
dc.date.available2015-01-27T10:05:04Z
dc.date.issued1975en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractThe mechanism of the corrosive action of sulphate reducing bacteria of the genus Desulfovibrio towards ferrous metals has been investigated. This corrosive action is anomalous when considered in the light of established knowledge of corrosion processes, since it occurs in the absence of oxygen, at more or less neutral pH values and at ordinary ambient temperatures. The hypothesis of von Wolzogen Kuhr and van der Vlugt, published in 1934, proposing that enzymic catalysis of sulphate reduction by cathodic charge constituted a "cathodic depolarizing" process, which appears t o be widely accepted as the most likely mechanism for this corrosive effect, is evaluated critically here in the light of established electrochemical and biochemical knowledge. The theoret ical arguments presented in this thesis show that this process, if it does occur, is unlikely to affect corrosion rates. The experimental results presented here indicate that all cathodic depolarizing activity demonstrated in pure cultures of these organisms is attributable to the cathodic activity of dissolved hydrogen sulphide produced by the organisms. The conclusions of other workers, quoted in support of proposed enzymic catalysis of charge transfer from cathodes to redox dyes in laboratory systems, are considered, in view of experimental work performed during this investigation, to be a misinterpretation of experimental results.en_ZA
dc.identifier.apacitationCostello, J. A. (1975). <i>The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/12327en_ZA
dc.identifier.chicagocitationCostello, John Anthony. <i>"The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Chemistry, 1975. http://hdl.handle.net/11427/12327en_ZA
dc.identifier.citationCostello, J. 1975. The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Costello, John Anthony AB - The mechanism of the corrosive action of sulphate reducing bacteria of the genus Desulfovibrio towards ferrous metals has been investigated. This corrosive action is anomalous when considered in the light of established knowledge of corrosion processes, since it occurs in the absence of oxygen, at more or less neutral pH values and at ordinary ambient temperatures. The hypothesis of von Wolzogen Kuhr and van der Vlugt, published in 1934, proposing that enzymic catalysis of sulphate reduction by cathodic charge constituted a "cathodic depolarizing" process, which appears t o be widely accepted as the most likely mechanism for this corrosive effect, is evaluated critically here in the light of established electrochemical and biochemical knowledge. The theoret ical arguments presented in this thesis show that this process, if it does occur, is unlikely to affect corrosion rates. The experimental results presented here indicate that all cathodic depolarizing activity demonstrated in pure cultures of these organisms is attributable to the cathodic activity of dissolved hydrogen sulphide produced by the organisms. The conclusions of other workers, quoted in support of proposed enzymic catalysis of charge transfer from cathodes to redox dyes in laboratory systems, are considered, in view of experimental work performed during this investigation, to be a misinterpretation of experimental results. DA - 1975 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1975 T1 - The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes TI - The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes UR - http://hdl.handle.net/11427/12327 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/12327
dc.identifier.vancouvercitationCostello JA. The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Chemistry, 1975 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/12327en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemistryen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherTheoretical Chemistryen_ZA
dc.titleThe mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processesen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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