MIC Corrosion Phenomenon
By : Ahsan Chaudhary
Microbial Induced Corrosion (MIC) is a phenomenon that occurs due to the metabolic activity of microorganisms on metal surfaces. This process can cause significant corrosion damage and result in the failure of metal structures, particularly those made of iron and steel. MIC is a common and often overlooked problem in various industries, including oil and gas, water treatment, and maritime transport.
The corrosion caused by MIC is often different from other forms of corrosion, such as uniform corrosion and pitting corrosion. It is characterized by localized corrosion and the presence of a biofilm, a layer of microorganisms that adhere to the metal surface. This biofilm can provide an ideal environment for microbial growth and the production of corrosive by-products.
The most common microorganisms involved in MIC are bacteria, such as sulfate-reducing bacteria (SRB), iron-oxidizing bacteria (IOB), and acid-producing bacteria (APB). These microorganisms can cause corrosion by producing hydrogen sulfide, organic acids, and other corrosive compounds.
The risk of MIC can be reduced by implementing proper materials selection, maintenance, and monitoring practices. Materials selection is important because some metals and alloys are more resistant to MIC than others. For example, stainless steel is known for its resistance to corrosion and is commonly used in applications where MIC is a concern.
Maintenance is also crucial in reducing the risk of MIC. Proper cleaning and inspection of metal surfaces can help to remove the biofilm and prevent the growth of microorganisms. In addition, the use of corrosion inhibitors can help to reduce the rate of corrosion by inhibiting the metabolic activity of microorganisms.
Finally, monitoring can help to detect the early stages of MIC and prevent significant damage. Regular monitoring of metal surfaces, such as through corrosion coupons, can help to detect changes in the rate of corrosion and provide information on the effectiveness of corrosion prevention measures.
In conclusion, MIC is a serious problem that can result in significant corrosion damage to metal structures. It is important to understand the mechanisms of MIC, the microorganisms involved, and the steps that can be taken to reduce the risk of MIC. By implementing proper materials selection, maintenance, and monitoring practices, the risk of MIC can be reduced, helping to ensure the safe and reliable operation of metal structures in various industries.
