电渗析技术在水泥厂废水零排放处理中的应用

在国家污废水资源化战略政策驱动下，工业废水零排放已成为必然趋势。作为重工业的水泥厂主要产生的循环冷却排污废水具有含盐量高、浓缩倍率大、Ca2+、Mg2+浓度高等特点，排放和回用前须进行科学有效的脱盐处理，以减少环境污染及负担。传统处理工艺存在加药量大、运行不稳定、易造成二次污染的剩余化学污泥量大等诸多的问题。采用混凝沉淀+反渗透+电渗析工艺深度处理水泥厂排污水的技术思路，探讨了电渗析单元在高盐废水处理中极致浓缩作用及特点并考察了其长期运行效果。在陕西省某水泥厂2个月以上的运行结果表明，电渗析系统脱盐率为24.7%，浓缩倍率为14.6倍，浓缩液平均电导率和产水量分别为147.7 mS/cm和0.07 m3/h。

APPLICATION OF ELECTRODIALYSIS TECHNOLOGY IN ZERO LIQUID DISCHARGE TREATMENT FOR WASTERWATER OF A CEMENT PLANT

Driven by the strategy and policy of national sewage and wastewater resource, zero liquid discharge of industrial wastewater has become an inevitable trend. As a heavy industry, the circulating cooling wastewater from cement plants is characterized by high salt content, high condensate ratio and high concentration of calcium and magnesium ions. Scientific and effective desalination treatment must be carried out before discharge and reuse to reduce the environmental pollution. The traditional treatment process has many deficiencies, such as large dosage, unstable operation, and large amount of residual chemical sludge which is easy to cause the secondary pollution. In this study, the technical idea of advanced treatment of wastewater by coagulation sedimentation+reverse osmosis+electrodialysis process was proposed. The function and characteristics of electrodialysis unit in the treatment of high salt wastewater were discussed, and its operation effect was investigated. Through the operation of a cement plant in Shaanxi province for more than 2 months, the results showed that the desalination rate of electrodialysis system was 24.7%, the concentration ratio of electrodialysis system was 14.6 times, the average conductivity and water yield of the concentrate liquid were 147.7 mS/cm and 0.07 m3/h, respectively.