电絮凝-高效澄清池联合技术在循环水排污水处理中的应用

Application research of electrocoagulation-efficient clarifying basin combined technology in treatment of circulating water drainage

为减轻高分子絮凝剂、助凝剂对膜处理系统的污堵,强化循环水排污水混凝澄清效果,北方某热电厂采用了电絮凝-高效澄清池联用技术对其循环水排污水进行预处理。通过系统调试,考察了不同电流密度、凝聚池pH值及碳酸钠加药量下,澄清池出水浊度、总硬度及总碱度的变化情况。结果表明,在电流密度为5.96 A/m2,凝聚池pH值约为11.0,碳酸钠加药量为170 mg/L时,电絮凝-高效澄清池对浊度、总硬度和总碱度去除率分别约为90%、60%和66%,平均出水浊度为0.9 NTU,总硬度为9.7 mmol/L,总碱度为1.2 mmol/L,出水水质稳定,满足后续膜处理工艺进水水质要求,并降低了后续膜系统污堵的风险。

To alleviate the fouling of the flocculant and polymer coagulant on the membrane treatment system and strengthen the clarification and coagulation effect in treatment of the circulating water drainage, a thermal power plant in northern China adopted the electrocoagulation-efficient clarifying basin combined technology to pretreat the circulating waste water. Through the system commissioning, the changes of the effluent turbidity, total hardness and total alkalinity of the clarifier were investigated under conditions with different current densities, pH values of the pool and sodium carbonate dosages. The results show that, under condition with current density of A/m^2, pH value of 11.0, and the sodium carbonate dosage of 170 mg/L in the electroflocculation-efficient clarifying basin system, the turbidity, total hardness and total alkalinity removal rates were approximately 90%, 60% and 66%, the average effluent turbidity, total hardness and total alkalinity were 0.9 NTU, 9.7 mmol/L and mmol/L, respectively. The effluent water quality was stable, which satisfied the requirements for subsequent membrane treatment process, and reduced the risk of fouling of the membrane system.