Sulfide scale catalysis of copper corrosion
By Jacobs, S. & Edwards, M.
Published in Water Research
2000
Abstract
The presence of soluble sulfides in a low alkalinity simulated drinking water increased copper pipe corrosion rates by more than one order of magnitude at pHÂ 6.5 and more than two orders of magnitude at pHÂ 9.2. Sulfides caused formation of a thick, black porous scale layer on pipes that did not significantly reduce pipe corrosion rates even after 9 months of exposure. In fact, both the anodic and cathodic reactions were catalyzed when sulfide containing scale was smeared onto a new copper pipe surface. Sulfide scales have a unique ability to accelerate copper corrosion even at pH>9.0, with potentially devastating consequences for copper tube performance in potable water applications.