Corrosion is one of the main problems of sewers around the world which causes huge quantities of both economic and ecological damages. Biological corrosion accounts for 20% of the total microbiological corrosion worldwide. The purpose of this study was to determine the corrosion potential in Ray sewers by H2S and ORP borne by wastewater. In this survey, H2S and Oxidation-Reduction Potential (ORP) were measured using a portable H2Smeter (MICRO III mark, model G203s) and a portable ORPmeter (mark Hana), respectively. The results were subsequently compared with those of CCTV (model IBAK) visual observations. The mean values of H2S in the sewers were found to be 0.83 ppm with a standard deviation of 0.931 at 9 a.m. and 1 ppm with a standard deviation of 1.155 at 3 p.m. Also, the mean values of ORP were -8.42 mV with a standard deviation of 60.43 at 9 a.m. and -37.3 mV with a standard deviation of 66.85 at 3 p.m. Based on the amounts of H2S and ORP produced in Ray sewers and also the results obtained from CCTV visual observations, the corrosion potential of wastewater in these sewers was judged to be considerably high.
