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

 

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dc.contributor.advisor Liesegang, E C en_ZA
dc.contributor.author Costello, John Anthony en_ZA
dc.date.accessioned 2015-01-27T10:05:04Z
dc.date.available 2015-01-27T10:05:04Z
dc.date.issued 1975 en_ZA
dc.identifier.citation Costello, J. 1975. The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/12327
dc.description Includes bibliographical references. en_ZA
dc.description.abstract 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. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Theoretical Chemistry en_ZA
dc.title The mechanism of cathodic depolarization exhibited by sulphate-reducing bacteria during metallic corrosion processes en_ZA
dc.type Doctoral Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Chemistry en_ZA
dc.type.qualificationlevel Doctoral
dc.type.qualificationname PhD en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Costello, 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/11427/12327 en_ZA
dc.identifier.chicagocitation Costello, 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/11427/12327 en_ZA
dc.identifier.vancouvercitation Costello 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/11427/12327 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


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