Patent ID: 8470238

Claim:
A method of reducing copper ion discharge from an open aqueous system, the open aqueous system having a copper-containing surface in contact with the water of the open aqueous system, the method comprising: adding to the open aqueous system a composition comprising a synergistic combination of (i) benzotriazole and/or salt(s) thereof and (ii) a substituted benzotriazole and/or salt(s) thereof, wherein said composition provides an erosion-resistant barrier on the copper-containing surface, and wherein said combination is resistant to degradation by exposure to halogen ions in the water of the open aqueous system and resistant to high turbidity of the open aqueous system, wherein the substituted benzotriazole and/or salt(s) thereof is selected from the group consisting of chlorobenzotriazole and/or salt(s) thereof, and nitrobenzotriazole and/or salt(s) thereof.