Sulfide‐induced copper corrosion

Sulfides can accelerate the corrosion of copper pipe and elevate concentrations of copper in drinking water. The presence of sulfides in potable water increases copper pitting and the release of copper corrosion by‐products. After 3 h of stagnation in a copper pipe, the average by‐product release of a synthetic drinking water that contained sulfides was 8.0 mg/L at pH 6.5 and 4.4 mg/L at pH 9.2. These concentrations represented a 5‐ and 50‐fold increase compared with water without sulfides. Sulfide‐induced corrosion problems might be ameliorated by removal of sulfides from the water, mechanical removal of the sulfide scale, chlorination, or deaeration. However, in the laboratory only mechanical removal of the sulfide scale and removal of sulfides from water were effective within a month. Utility case studies strongly support a relation between sulfides and increased copper corrosion problems.