6. Bacteria and corrosion of non-metallic materials

In concrete structures such as septic tanks, wastewater treatment plants and sewage networks, hydrogen sulfide can be released. Thiobacilli are the sulfo-oxidizing bacteria (SOB) most often cited in cases of concrete biodegradation. The bacteria degrade sulfur compounds derived from sulfates and organic products of plant and animal origin, or sulfonates contained in detergents. Sulfuric acid H ₂ SO ₄ can be formed locally. All materials based on calcium hydraulic binders are highly sensitive to contact with these acids