正弦交流电絮凝处理含锌电镀废水的研究

Study on treatment of zinc-containing electroplating wastewater by sinusoidal alternating current electrocoagulation

[目的]电镀废水中的Zn^(2+)污染控制是当前重要的工业水环境技术问题。[方法]采用正弦交流电絮凝技术和自制的电絮凝装置从废水中除去Zn^(2+)。采用数值模拟的研究方法对电絮凝装置进行了流场分析,并通过实验研究了溶液初始pH、电流密度、初始锌离子浓度、反应时间等因素对去除Zn^(2+)的影响,使用响应面优化方案的Box-Behnken设计获得Zn^(2+)最高去除效率的最佳工艺参数。[结果]钛篮孔板大于3层有利于实现电絮凝装置流场均匀分布;在pH=9、含120 mg/dm^(3)Zn^(2+)的模拟废水溶液中,施加电流密度为0.31 A/m2、频率为50 Hz正弦交流电,通电21.3 min,Zn^(2+)的去除率可达到98.80%。[结论]响应面优化可用于正弦交流电絮凝处理含Zn^(2+)废水的过程。

[Introduction]Treatment of electroplating wastewater containing Zn^(2+)is an important technical problem of water pollution control in industry.[Method]The removal of Zn^(2+)from electroplating wastewater was studied by sinusoidal alternating current coagulation(SACC)with a homemade electrocoagulation device.The flow field in the electrocoagulation device was analyzed by numerical simulation.Four factors affecting the removal efficiency of Zn^(2+)i.e.initial Zn^(2+)concentration,initial pH value,current density,and reaction time were discussed,and optimized by Box-Behnken design(BBD).[Result]The removal efficiency of Zn^(2+)from an artificial wastewater containing Zn^(2+)120 mg/dm^(3)with a pH of 9 was up to 98.80%after electrolysis with a 50 Hz AC at current density 0.31 A/m^(2)for 21.3 min.[Conclusion]The response surface methodology is applicable for optimizing the treatment of Zn^(2+)-containing wastewater by SACC.