On the need for more realistic experimental conditions in laboratory-based microbiologically influenced corrosion testing

Microbiologically influenced corrosion (MIC) encompasses a complex suite of processes that can result in costly and dangerous acceleration of corrosion rates. However, the complexity of MIC, and the wide range of conditions in which it occurs in the natural environment, has resulted in researchers performing tests under a wide range of laboratory conditions. This scattergun approach can potentially lead to ambiguous results and can compromise the ability to compare data from different tests. Therefore there is a need for the corrosion community to develop more realistic and standardised approaches to laboratory-based testing. This paper seeks to illustrate the challenges by examining a range of test parameters that can influence the results of MIC studies, using Escherichia coli and carbon steel as a model system. The experimental parameters considered here include test media composition, immersion temperature, immersion time and medium replenishment. It is shown that each of these parameters can exert a significant effect on the outcome of the study, thus supporting the contention that more realistic testing procedures are required to develop a better understanding of MIC processes and ultimately allow predictive management of MIC.