Microbes can accelerate corrosion through a phenomenon known as Microbiologically Influenced Corrosion (MIC). Unlike traditional corrosion caused by purely chemical or electrochemical reactions, MIC involves complex interactions between microorganisms, environmental chemicals, and metal surfaces. These interactions can initiate or accelerate corrosion, leading to structural failures, costly repairs, and system inefficiencies in industries like oil and gas, water treatment, and manufacturing.
Mechanisms of Microbial Corrosion
1. Production of Corrosive Metabolites
Certain microbes, such as sulfate-reducing bacteria (SRB), generate hydrogen sulfide (H₂S) as a metabolic byproduct. H₂S reacts with iron to form iron sulfide (FeS), a corrosive compound that accelerates metal deterioration. Additionally, other microbes produce sulfuric acid, organic acids, and carbon dioxide (CO₂), all of which contribute to acidification and material breakdown.
2. Biofilm Formation
Microbes adhere to surfaces and form biofilms—structured, protective layers that trap corrosive agents like H₂S, acids, or oxygen gradients. Biofilms create localized environments that can promote pitting and crevice corrosion, two of the most aggressive and damaging types of corrosion.
3. Electron Uptake
Certain microbes, such as methanogens and iron-reducing bacteria, can directly uptake electrons from metal surfaces. By disrupting the metal’s electrochemical stability, these microbes accelerate corrosion and undermine the material’s integrity.
The Impact of MIC
Microbiologically Influenced Corrosion is a significant issue in industries that rely on metal infrastructure, such as pipelines, tanks, and equipment. In oil and gas systems, MIC is a leading cause of pipeline leaks, equipment degradation, and system inefficiencies. If left unmanaged, MIC can result in unplanned downtime, safety hazards, and substantial repair costs.
Prevention and Mitigation
Preventing MIC requires a proactive approach that combines regular monitoring and effective microbial control strategies:
- ATP Testing: LifeCheckTM ATP testing provides real-time insights into microbial activity, enabling early detection of MIC risks.
- Biocide Treatments: Regular use of biocides reduces microbial populations, helping to prevent biofilm formation and production of damaging metabolites.
- Effective Cleaning Protocols: Proper cleaning of metal surfaces, such as pigging programs, removes existing biofilms and minimizes conditions that promote MIC.
- Molecular Microbiological Methods (MMM): DNA testing techniques can help identify specific microbial species contributing to corrosion, allowing targeted control strategies.
Why Is MIC Monitoring Important?
Regular monitoring not only helps detect microbial activity early but also allows for optimized treatment programs and protects assets. By combining ATP testing with biocide treatments and molecular diagnostics, industries can mitigate corrosion risks, extend equipment lifespan, and ensure operational efficiency.
Need Help or Want to Learn More?
Our team of experts is here to assist you with your microbiological monitoring needs. Whether you have questions, need technical support, or want to learn more about LifeCheckTM ATP testing, contact LuminUltra® Support to get started.