Microbially induced corrosion (MIC) is a growing concern for industries that rely on concrete infrastructure in environments exposed to hydrogen sulfide (H2S). From wastewater treatment plants to sewer systems, this unique form of biochemical corrosion can lead to the rapid degradation of concrete, jeopardizing the structural integrity and longevity of key infrastructure.

MIC occurs when sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans, convert H2S gas into sulfuric acid, which reacts with concrete components and causes progressive deterioration. Environmental factors such as humidity, water chemistry and transit time of wastewater exacerbate this process, making certain settings more vulnerable to MIC. The impact on concrete can be devastating due to the material loss from the exposed surface, spalling (surface chipping) and significant weakening of the remaining material. As the sulfuric acid (H2SO4) reacts with concrete, it triggers chemical reactions that compromise its strength and load-bearing capacity, potentially leading to expensive repairs or structural failures.