ABSTRACT
Monitoring of microbiologically influenced corrosion (MIC) is essential to prevent costly damage to infrastructure, ensure safety, and maintain operational efficiency. MIC can lead to accelerated degradation of materials, particularly in water systems, pipelines, and storage tanks. Ideally, effective MIC monitoring methodologies should be low-cost, minimally labor-intensive, and capable of generating actionable insights to ensure feasibility. In practice, a range of techniques are available, each with distinct strengths and limitations. Coupons are widely used to assess physical deterioration of steel surfaces, offering tangible and visual evidence of corrosion progression. Electrochemical methods, such as linear polarization resistance or electrochemical impedance spectroscopy, provide insights into corrosion kinetics and metal integrity. Chemical monitoring can detect shifts in redox conditions or the presence of corrosive metabolites. Meanwhile, biological approaches, such as quantitative polymerase chain reaction, next-generation sequencing, or microbial culturing, offer detailed information on the microbial communities driving MIC. A comprehensive MIC monitoring campaign must integrate multiple lines of evidence to provide a full diagnostic of the local corrosion environment. This includes not only surface-level observations but also the monitoring of the bulk environment (e.g., water chemistry, nutrient availability, and microbial load), surface evolution (e.g., biofilm formation and scaling), and the impact on metal integrity over time.
