基于降低拉森指数的再生水混凝处理工艺优化研究

Research on the optimization of reclaimed water coagulation treatment process by reducing the Larson index

针对城市再生水输配管线的腐蚀控制问题,通过监测水中浊度、氯离子、硫酸盐、碳酸氢根,调节混凝过程最佳运行工况,控制拉森指数以减轻管网腐蚀。实验结果表明,最佳混凝剂为PAC,最佳投加量为12 mg/L,最佳混凝条件为快搅60 s、速度300 r/min,慢搅15 min、速度60 r/min,沉淀时间30 min。在此工况下拉森指数为0.999,能够有效控制管网腐蚀,减小后续工艺压力。

Aiming at the corrosion control problem of urban reclaimed water distribution pipeline,by monitoring the water turbidity,chloride,sulfate,and bicarbonate,the best operation conditions in the process of coagulation are adjusted and Larson index is controlled to alleviate the pipeline corrosion. The experimental results show that the optimum coagulant is PAC,whose optimal dosage is 12 mg/L,the best coagulation conditions are as follows：rapid stirring time is 60 s,rapid stirring rate 300 r/min,slow stirring time 15 min,slow stirring rate 60 r/min,and settling time 30 min. Under the above conditions,Larson index is 0.999,being able to control the reclaimed water pipeline corrosion, and reduce the pressure in the subsequent process.