Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.
Water Environ Res. 2010 Dec;82(12):2346-56. doi: 10.2175/106143010x12681059117094.
Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21-day average corrosion rate with the last 5-day average corrosion rate, the latter being approximately 50% lower than the former.
二级处理后的城市废水是发电厂冷却水系统补给水的有前途的替代水源，特别是在干旱地区。本研究进行了实验室和现场测试，以评估二级处理后的城市废水中各种金属和金属合金在冷却系统中的腐蚀性。根据不同的化学处理方法，评估了不同的腐蚀控制策略。正磷酸盐在二级处理后的城市废水中含量丰富，促成了基于磷的缓蚀剂超过 80%的沉淀去除。甲苯三唑对铜的腐蚀具有有效抑制作用（抑制效率大于 95%）。在自由氯 1mg/L（以 Cl2 计）存在下，低碳钢的腐蚀速率比在单氯胺 1mg/L（以 Cl2 计）存在下高约 50%，表明单氯胺比自由氯腐蚀性更小。在金属合金上观察到的结垢层有助于抑制腐蚀，可以通过比较低碳钢 21 天的平均腐蚀速率与最后 5 天的平均腐蚀速率来看出，后者比前者低约 50%。
