扩散渗析—电渗析法回收盐酸酸洗废水中的酸和铁

为了达到盐酸酸洗废水"零排放"的要求,采用扩散渗析—电渗析联合工艺技术,进行回收酸洗废水中的盐酸和铁的试验研究。考察了扩散渗析装置料液进水流量、蒸馏水与酸洗废水流量比、电渗析装置阴极室进水pH值、阴极室和阳极室进水流量和槽电压对酸洗废水中盐酸和铁回收效果的影响。结果表明,用不锈钢作阴极,自制改性Ti/SnO2-Sb2O3/PbO2电极作阳极,采用DF120型均相阴离子交换膜,当扩散渗析装置料液进水流量为0.35L/h,维持蒸馏水与酸洗废水流量比为1,电渗析装置阴极室进水pH值为2.50,阴极室和阳极室进水流量为0.06L/h,槽电压为10V时,回收盐酸浓度平均为0.2mol/L,盐酸回收率平均为66.7%;出水中Fe2+浓度平均为99.5mg/L,铁回收率均可达到88%。

The hybrid diffusion dialysis-electrodialysis process was employed to recover HCl and Fe from the HCl pickling wastewater.The reaction parameters included the flow rate and flow rate ratio（Qw/Q）fof diffusion dialysis,the pH of cathode electrolyte solution,flow rate and cell voltage of electrodialysis were considered,and the effects of these factors on the HCl and Fe recovery rate were studied.In hybrid diffusion dialysis and electrodialysis process,the DF120 anion-exchange membrane was employed in the dynamic electrodialysis system,and the stainless steel cathode,the Ti/SnO2-Sb2O3/PbO2 anode were employed in the electrodialysis system.The optimal operating conditions are shown as follows：the flow rate of diffusion dialysis was 0.35 L/h,the flow rate ratio（Qw/Q）fof diffusion dialysis was 1,the pH of the cathode electrolyte solution of electrodialysis was 2.50,the flow rate of electrodialysis was 0.06 L/h,and the cell voltage of electrodialysis was 10V.Under the conditions,the results of experiments on HCl pickling wastewater demonstrated that the HCl recovery rate reached 66.7%,and the Fe recovery rate reached 88%.In addition,the recovered HCl concentration reached 0.2mol/L and the Fe2＋ average concentration of the effluent was 99.5mg/L.