Corrosion management in power plant cooling systems using tertiary-treated municipal wastewater as makeup water

Additional tertiary treatment of secondary-treated municipal wastewater (MWW) is necessary to reduce its scaling potential for use in power plant cooling systems. In this study corrosiveness of three tertiary-treated municipal wastewaters (acidified MWW, MWW treated by nitrification–filtration, and MWW treated by nitrification–filtration and granular activated carbon adsorption) towards mild steel, copper, and cupronickel alloys was assessed. pH, ammonia, and organic matter were identified as important corrosion influencing parameter in tertiary-treated municipal wastewater. Corrosiveness of wastewater towards metal alloys increased after tertiary treatments. However, corrosion of mild steel and copper alloys was controlled within acceptable limits using the corrosion inhibitor tolyltriazole.

► Tertiary treatment increases corrosiveness of secondary treated municipal effluent.
► Ammonia induced corrosion in tertiary treated municipal effluent can be controlled.
► Removal of organic matter from municipal wastewater enhances copper alloy corrosion.
► Tolyltriazole inhibits mild steel and copper alloy corrosion in treated effluent.