Studying the synergistic effects of microbes and environment on carbon steel pipeline corrosion

Abstract

Biological corrosion is a process whereby deterioration of a metal occurs directly or indirectly due to the activity of, and interaction with, living organisms such as bacteria or algae. Micro-organisms can influence corrosion to occur at much higher rates than normally anticipated, leading to premature and sometimes catastrophic failure. This phenomenon is known as microbial influenced corrosion (MIC). MIC can accelerate corrosion in buried carbon steel pipes in small, isolated areas causing reduced pipe performance and ultimately failure and thus disruption to potable water services. While there is a detailed knowledge base of the electrochemical processes associated with the corrosion of carbon steel in a wide variety of conditions and uses, limited research has previously been undertaken into understanding the specific processes when bacteria are involved. This project aims to study the fundamental processes relating to how bacteria influence the electrochemical processes of steel corrosion and how the behaviour of the bacteria is influenced in turn by the electrochemical processes. It is focussed principally on the conditions experienced at the micro-interface between steel and the surrounding soil, in the context of buried metallic pipes. The focus of this paper is to review the literature surrounding MIC of carbon steel pipelines, highlighting the areas where there is a lack of information, and, to design and conduct preliminary studies to optimize a system for assessing the corrosion behaviour of a carbon steel pipeline material in nutrient enriched agar media, a gel commonly used to isolate pure cultures of bacteria. The findings from the initial review and preliminary studies are presented, as well as an articulation of the research problem. Show more