膜电解处理含铜电镀废水研究

Treatment of Electroplating Wastewater Containing Cu^(2+) by Membrane Electrolysis Method with Ammonia Electrolyte

以氨水为电解质处理含铜电镀废水的膜电解过程中,通过阳离子交换膜迁移的主要离子包括Cu2+、NH4+及H+,废水中Cu2+的去除方式包括在电场力和渗析作用下废水中Cu2+通过阳离子交换膜进入阴极室,以及由于NH4+的迁移,在废水中形成Cu(OH)2絮体。采用膜电解技术,在V(氨水)∶V(纯水)分别为3∶5、2∶5、1∶8的情况下,对ρ(Cu2+)=109 mg/L电镀废水进行膜电解去除废水中Cu2+的实验研究。结果表明,在V(氨水)∶V(纯水)为3∶5时,电解5 h,废水中Cu2+去除率为94.71%,ρ(Cu2+)为5.79 mg/L;废水中形成的Cu(OH)2絮体中Cu2+的质量浓度约占膜电解过程去除ρ(Cu2+)的40%。

The main ions transferred through cation exchange membrane were Cu2＋,NH4＋and H＋when the electroplating wastewater containing Cu2＋was treated by membrane electrolysis method with ammonia electrolyte.The removal mechanism of Cu2＋ions in wastewater was composed by the transfer of Cu2＋ions into the cathode cell through membranes under the electric field force and dialysis,and the Cu（OH）2 flocculation precipitation because of the transfer of NH4＋ ions.The treatment of electroplating wastewater was carried out under the ratio of ammonia to pure water of 3∶ 5,2∶ 5 and 1∶ 8.The results show that the Cu2＋ removal efficiency was 94.71% under the ratio of ammonia to pure water of 3∶ 5 and treatment time of 5 h.In the removal Cu2＋ ions,there were about 40% caused by the Cu（OH）2 flocculation precipitation.The concentration of Cu2＋in wastewater was about 5.79 mg/L left.