The effective use of both oxidizing and non-oxidizing biocides for control of MIC in cooling water systems was evaluated. Traditional off-line methods of monitoring and control were compared to a new on-line method. The on-line method utilizes a patented localized corrosion monitor (LCM) to monitor changes in localized corrosion rates within laboratory scale and pilot cooling tower systems under various biocide treatment regimes. Under many of these conditions, the changes in localized corrosion rates can be directly correlated to specific biocide feed. Standard culture techniques for indicator microorganisms of MIC such as Acid Producing Bacteria (APB) and Sulfate Reducing Bacteria
(SRBs) were also used to evaluate biocide performance. These tests were useful for selecting the best biocides against anaerobes associated with MIC, but the on-line LCM monitor was more effective in
adequately providing the correct biocide dosage.