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Investigation of Mechanisms of Microbiologically Influenced Corrosion and Mitigation of Field Biofilm Consortia

Li, Yingchao
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1436306238

Abstract Details

, Doctor of Philosophy (PhD), Ohio University, Chemical Engineering (Engineering and Technology).
Microbiologically influenced corrosion (MIC) has been a popular research topic in the corrosion field due to continuous failures caused by MIC. It has caused billions of dollars in financial losses in the United States alone every year. Biofilms areoften blamed for causing MIC. Sulfate reducing bacteria (SRB) are the principalspecies in publications about MIC research and case studies of MIC failure. Other than SRB, some other species are capable ofinitiating MIC as well. More attention and resources have been focused on MIC research than ever before. Many mechanisms and models have been reported to explain how MIC occurs. The cathodic depolarization theory (CDT) was well-accepted and inspired most of the other theories, although with a few limitations. In 2009, the Biocatalytic Cathodic Sulfate Reduction (BCSR) theory was proposed to describe the process of MIC caused by SRB from an electrogenic perspective. In this research, the starvation test and the electron mediator testwere doneusing a field collected biofilm consortium to study the BCSR theory. Biofilms caused more severecorrosion in the modified ATCC 1249 medium, in which the carbon sources were reduced, than in the full strength ATCC 1249 medium. This supports the BCSR theory that when sessile cells lack a carbon source, they switch the electrondonorsfroma carbonsource to elementaliron. The electron mediator test was done in the modified ATCC 1249 medium, in which all carbon sources were completely removed. Riboflavin was chosen as the electron mediator. The maximum pit depth in the presence of riboflavin was less, however,more weight loss was obtained. It indicated that in the presence of the electron mediator the biofilm wasable to attack the coupon evenly. Therefore, more general corrosion instead of localized corrosion was observed on the coupon surface when riboflavin was added. After the mechanistic studies had beenaddressed, the mitigation of the field collectedbiofilm consortia was investigated. First of all, twoD-amino acids,D-serine and D-threonine, were individuallytested as biocide enhancers of tetrakis hydroxymethyl phosphonium sulfate (THPS)in the mitigation of Desulfovibrio vulgaris biofilms. The results show that they are effective biocide enhancers for THPS. The mechanism of D-amino acids triggering the biofilm dispersal was investigated.Secondly, a novel biocide cocktail of glyceryl trinitrate(GTN) and caprylic acid (CA) was tested. D-methionine enhanced the efficacy of GTN + CA. Finally, D-amino acid mixtures were tested as biocide enhancers of THPS, alkyldimethylbenzylammonium chloride (ADBAC), and tributyl tetradecyl phosphonium chloride(TTPC) in the mitigation of field collectedbiofilm consortia. Individual D-amino acids were not able to enhance the efficacy of biocides since the effect of D-amino acids triggering biofilm disassembly was specific to the types of D-amino acid and the species. Different species require different D-amino acids as signal molecules. Three different D-amino acid mixturesincluding 4, 8, and 12 different D-amino acids were tested. The results show that these three D-amino acid mixtureswere able to enhance the efficacy of THPS, ADBAC, and TTPC in both biofilm prevention and removal tests.
Tingyue Gu (Advisor)
Srdjan Nesic (Committee Member)
Monica Burdick (Committee Member)
Howard Dewald (Committee Member)
Xiaozhuo Chen (Committee Member)
Chemical Engineering
Microbiologically influenced corrosion; MIC mechanism; field biofilm consortia; biofilm mitigation; biocide enhancer; CLSM

Recommended Citations

Citations

  • Li, Y. (2015). Investigation of Mechanisms of Microbiologically Influenced Corrosion and Mitigation of Field Biofilm Consortia [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1436306238

    APA Style (7th edition)

  • Li, Yingchao. Investigation of Mechanisms of Microbiologically Influenced Corrosion and Mitigation of Field Biofilm Consortia. 2015. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1436306238.

    MLA Style (8th edition)

  • Li, Yingchao. "Investigation of Mechanisms of Microbiologically Influenced Corrosion and Mitigation of Field Biofilm Consortia." Doctoral dissertation, Ohio University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1436306238

    Chicago Manual of Style (17th edition)

ohiou1436306238
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This open access ETD is published by Ohio University and OhioLINK.