Microbiological Influenced Corrosion (MIC) describes the corrosion of surfaces caused by microorganisms. These microorganism include bacteria, fungi, yeasts and algae. This kind of corrosino is sometimes also called biocorrosion.
For example, we at Merus, encounter this form of corrosion in cooling circuits or pipelines
Aerobic and anaerobic bacteria and microbes are found in the fluids we deal with in the installations. Some of these microorganism or so nasty, they produce acids or sulfuric acid salts as a metabolic waste product. These substances can cause corrosion on the inside of pipes. Pipeline walls or metallic surfaces that are not resistant to this, are usually severely affected. The result in some cases is pitting or leaks in the line. This means that the general service life of the components is reduced.
Biocorrosion and biofilm
The problem caused by biocorrosion is aggravated when the bacteria form a biofilm. This does not flow off with the liquid but settles in one place. It is therefore the habitat of the bacteria and microorganisms. In its entirety, it provides a protective space for these living organisms. Due to these circumstances, the acids produced are always released into the surrounding liquid at the same point. As a result, the pipe is more damaged by biocorrosion at this point.
One of the best-known types of bacteria that cause biocorrosion are so-called desulfurizers, i.e. bacteria that reduce sulfate to hydrogen sulfide.
What can Merus do against MIC or biocorrosion?
Our Applications section describes in detail how the Merus ring works against biofilms and biofouling. Once the biofilm and microorganisms disappear from the pipe, the most serious problems with biocorrosion usually solve themselves. After installation of the Merus Ring, the habitat for microorganisms gradually becomes more „uncomfortable“ and ultimately destroyed. Thus, the number of organisms in the system rapidly decreases as reproduction is made more difficult and permanently prevented. Since the Merus Ring additionally reduces the previously progressive corrosion in the pipe, both functions of the installation support each other excellently.
See also a case study in a refinery, where corrosion and the microorganism were reduced a lot.