Effect of Photosynthetic Biofilms on the Open-Circuit Potential of StainlessSteel

摘要

Periodic illumination of photosynthetic biofilms on American Iron and SteelInstitute (AISI) 316 stainless steel resulted in evolution of oxygen (1-7 mg.1-1) and a corresponding increase in open circuit potential (Ecorr) from 2 to 15 mV. The change in Ecorr depended on the interval of illumination. When the dark cycle began elevation in potential was followed by an immediate drop. Illumination did not affect Ecorr in sterile systems of in systems that contained only nonphotosynthetic eubacteria. Radiated heat from illumination accounted for changes of 4 to 5 deg C in temperature which, in the absence of oxygen production, should decrease dissolved oxygen by 0.75 mg.1-1 and decrease Ecorr by 1 mV. Positive shifts of Ecorr induced by periodic illumination of photosynthetic biofilms are primarily the result of oxygen production. Biofouling, Corrosion, Biodeterioration, Electrochemistry.