Microbiologically influenced corrosion is mainly caused by the biological activity in the biofilm,which clearly illustrates the role of attached bacteria in the form of biofilm in initiating or acceleratingcorrosion. Although it has been proven that electrochemical methods can prevent the formation ofbiofilms on metal surfaces, the special effect of cathodic polarization in bacterial attachment andgrowth is still inconclusive. The purpose of this work was to investigate the effect of cathodicpolarization on the attachment of iron-oxidizing bacteria (IOB) in seawater during the initial stage ofbiofilm formation. Results showed that under the polarization potential of ?1050 mV vs. SCE, IOBattachment and biofilm growth were well controlled. Further, the potential of ?1050 mV vs. SCEexhibited more effective inhibitory effect on IOB-induced pitting corrosion than that of ?700 mV vs.SCE, which was related to the accumulation of electrons on the metal surface during cathodicpolarization. The cathodic potential of ?1050 mV vs. SCE also altered the electrochemical parameters atthe metal-biofilm interface, such as the increase of pH and the formation of protective calcareousdeposits, which contributed to protect the metal from IOB-induced corrosion..
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