A Brief Review of General Patterns of MIC of Carbon Steel and Biodegradation of Concrete

Abstract

MIC (Microbiologically influenced corrosion) is an electrochemical type of corrosion enhanced by some types of micro-/ macro-organisms. However, in this paper, MIC will be used to address the corrosion enhanced by micro-organisms. In order for MIC to occur, two minimum requirements are (i) vulnerability of the material and (ii) existence of environmental factors that are favoring MIC. This type of corrosion is known to affect both metals and non-metals. On the other hand, the factors that render the environment suitable for MIC are, but not limited to, pH, temperature, systems, dynamics, and availability of chemicals such as carbon source necessary for sustaining the growth of corrosion-enhancing bacteria. Under natural conditions, bacteria are usually found in non-pure, mixed communities known as “mixed cultures” or “microbial consortia”. When a certain material is exposed to a known, in-engineering-terms “uniform” group of bacteria (such as all Desulfovibrio desulfuricans), it is easier to explain the corrosion mechanism (s) than a mixed culture will be affecting different constructing materials of a given system. In this paper, corrosive effects of some known types of bacteria (such as sulphates reducing bacteria and sulphur oxidizing bacteria) on enhancement of corrosion of carbon steel and concrete are reviewed. At the end, some general guide lines for prevention of MIC on these materials are also outlined.