Corrosiveness of different treated municipal wastewaters used as power plant cooling system makeup water: a bench-scale evaluation

Corrosion of metals and metal alloys in a recirculating power plant cooling system is a major operational concern and is exacerbated when using treated municipal wastewater as makeup water, due to the degraded water quality. In this study different treated municipal wastewaters were used in a bench-scale water recirculation system, simulating cooling water conditions in power plant cooling systems. The treated municipal wastewaters used were: secondary treated municipal wastewater (SMW) with pH reduction, SMW with nitrification-filtration, and SMW with nitrification-filtration-granular activated carbon (GAC) adsorbtion. The corrosiveness of these treated municipal wastewaters to mild steel, copper and cupronickel alloys were analyzed. The efficacy of Tolyltriazole (a corrosion inhibitor) was also analyzed in this study. Results showed tolyltriazole successfully reduced the corrosion rates of mild-steel copper and cupronickel alloys in all the systems