Microbiologically influenced corrosion in Aberdeen Harbour

This project was developed in partnership with Aberdeen Harbour Board to assess the likelihood of MIC occurrence on steel pilings in Aberdeen Harbour, and to predict the effect of various environmental variables on this process. The literature review (Chapter 1) describes the corrosion process and presents the evidence for the role of microorganisms in aggressive forms of localised corrosion. Chapter 3 details the development of general methods that were then used in subsequent experimental chapters. Data from various surveys carried out in Aberdeen Harbour were analysed in Chapter 4 for pertinent information. This information was used to plan microcosm experiments (reported in chapter 5) designed to mimic field conditions in Aberdeen Harbour. These microcosm experiments were initially carried out over a range of temperatures (100C to 300C) and corrosion rate increased as temperature increased. The initial microcosm experiment demonstrated that carbon addition had little effect on corrosion rate, whereas N & P addition increased corrosion rates, both biotically and abiotically. The second microcosm experiment, reported in Chapter 6, demonstrated that the addition of a sediment bacterial inoculum did not affect bacterial population densities or rate of steel weight loss, suggesting that an inoculum from the water column alone would suffice to produce a biofilm containing SRB and thiobacilli that may affect steel corrosion. The third microcosm experiment presented in Chapter 7, demonstrated that although increased light intensity caused an increase in the rate of corrosion, the effect was abiotic, rather than biotic. The field experiment carried out in Aberdeen Harbour, and reported in Chapter 8, showed that in situ corrosion processes were similar to those observed in the laboratory. The findings from this research project can be used by Aberdeen Harbour Board to develop strategies that will help predict the occurrence, and severity, of MIC within the harbour.EThOS - Electronic Theses Online ServiceGBUnited Kingdo