AN INNOVATIVE METHOD FOR ON-LINE MONITORING OF BIOCORROSION IN SEAWATER

Biofilms that form on metallic surfaces can exert a significant influence on corrosion of shipboard seawater piping and heat exchangers. Early detection of biofilm formation permits the system operator to implement mitigation measures when they are most effective. A novel electrochemical sensor has been developed for on-line monitoring of biological activity and biocorrosion. The two-electrode probe utilizes a stack of identical stainless steel electrodes that are polarized relative to one another for a short time each day. This probe has demonstrated its effectiveness in detecting biofilm formation in fresh water environments. Biofilm activity is signalled by an increase in the current required to achieve the pre-set polarization potential and by the appearance of a low-level current between the electrodes, even when the applied potential is removed. This probe configuraiton also permits biofilm detection by monitoring changes in the ohmic resistance along probe surfaces. The proposed concept has been shown to be effective in signalling the formation of biofilm, te precursor to microbiologically influenced corrosion, in scale-forming and scale-dissolving fresh water environments. During Phase I, the feasibility of adapting this approach for detecting biofilm formation and microbiologically influenced corrosion in seawater will be demonstrated.