Electrochemical techniques including linear polarisation resistance, harmonic distortion analysis and electrochemical noise have been used to study the corrosion of carbon steel due to sulphate reducing
bacteria (SRB) in typical seawater injection systems. The effects of SRB activity on the electrochemistry of the corroding interface and the effects of biocide treatments have been examined. Electrochemical
monitoring provides a reliable means of detecting corrosion due to SRB activity, and provides new information regarding the effectiveness of biocide treatments. This study was instigated to provide a controlled laboratory investigation into bacterial metabolic activity and the associated corrosion activity of carbon steel as determined by electrochemical corrosion monitoring. SRB activity results in the corrosion of carbon steel, primarily due to the formation of hydrogen sulphide. In sea-water injection systems bacterial activity is usually monitored by sampling techniques, which is a time consuming process. Biocide activity may be controlled using a variety of biocide treatment regimes. Inadequate biocide treatment can result in excessive SRB activity, which may result in catastrophic corrosion of plant and pipe-work. Electrochemical corrosion monitoring has the advantage of having a quick response time, and modern techniques may be used to assess both uniform and localised (pitting) corrosion activity.