(702f) Real Time Corrosion Monitoring of Microbially Induced Corrosion in Water-Cooling Systems

Microbially induced corrosion (MIC) is an insidious form of corrosion that is difficult to detect. Moreover, it is extremely challenging to quantify the degree to which certain structures and components may be affected by MIC. There is, therefore, a significant risk associated with microbial activities related to corrosion, especially for critical assets operating in remote areas for long periods of time. Water-cooling systems and heat exchangers are known to suffer microbial contamination to various degrees. Moreover, for certain corrosion resistant alloys (CRAs) used in pressure-retaining components there is always a possibility that localized corrosion will eventually transition into stress corrosion cracking (SCC). Therefore, assessing whether microbial contamination of water-cooling systems leads to MIC is of great scientific and technological significance. The ability to monitor the kinetics of MIC in real time is also paramount.
Shewanella putrefaciens strain MR-1 is an iron-reducing bacterium used in this study to understand the mechanism of MIC in aerobic and anaerobic conditions. This system produces changes in the form of pH, oxygen and ion concentrations, bilayer formation, metabolic pathway, among others. The objective of this work is to assess the impact of MIC in carbon steel (UNS C1018) by using electrochemical techniques such as linear polarization resistance (LPR), impedance and Tafel plots using the split cell method. The outcome of this investigation will help elucidating one of the most challenging questions in MIC research of water-cooling systems, i.e. under which conditions microbial contamination of a particular system by a given community of microorganisms leads to microbially induced corrosion.