Field evaluation of corrosion control using regenerative biofilms (CCURB)

Closed-loop sidestream systems that simulate the service water conditions at energy generating facilities are being used to evaluate the concept of corrosion control using regenerative biofilms (CCURB) at Three Mile Island Nuclear Power Station. These biological treatments are being developed as alternatives to the use of biocides and chemical inhibitors for controlling corrosion. Electrochemical impedance spectroscopy (EIS) measurements were performed on small metal disc specimens of mild steel, stainless steel, and cartridge brass under different flow conditions in service water inoculated with a consortium of adapted CCURB bacteria (test sidestream). A comparison of the electrochemical and SEM results for the test specimens with those for metal samples simultaneously exposed to unaltered service water (control sidestream) indicates that the CCURB bacteria reduced the corrosion rates of these materials under simulated service water conditions. Pitting analyses of the brass specimens verify the conclusions based on electrochemical results. The results obtained so far suggest that this "probiotic" approach to controlling corrosion in industrial settings may be possible.