Microbial corrosion of metals (a review)

Abstract

Biocorrosion processes of metal surfaces are associated with microorganisms, or the products of their metabolic activities including enzymes, exopolymers, organic and inorganic acids, as well as volatile compounds such as ammonia or hydrogen sulphide. These can affect cathodic and/or anodic reactions, thus altering electrochemistry at the biofilm/metal interface. Various mechanisms of biocorrosion, reflecting their variety of physiological activities carried out by different types of microorganisms, are identified and recent insights into these mechanisms reviewed. Many recent investigations have centred on the microbial-influenced corrosion of ferrous and copper alloys and of particular interest are Desulfurvibrio species, Thiobacillus species, Pseudomonas, Methanobacterium, Methanospirillum, Escherichia coli, and Ferrobacillus ferrooxidans. Some of the factors that influence biocorrosion include; pH, temperature, oxygen, moisture and the nature and types of metal.