摘要：

印刷电路板（PCB）制造过程中产生的酸性清洗废水含有2~6 g/L的铜离子（Cu²⁺），将其回收利用对于PCB制造行业绿色发展及减污降碳协同增效具有重要意义。以化学沉淀法、离子交换和吸附法为代表的传统处理方法在处理PCB酸性清洗废水的过程中面临易发生二次污染、资源浪费严重、处理效率过低等问题。采用基于物理浓缩和化学还原耦合模式的“膜浓缩-电沉积”复合工艺，通过前置膜浓缩系统的纳滤实现Cu²⁺、Na⁺的分离，再经反渗透和特种分离可将Cu²⁺浓缩至32 g/L。后端电沉积单元在直流电流500~900 A条件下实现Cu²⁺的选择性还原，金属铜回收率>95%，回收纯度>99.5%。直接经济效益为1.19万元/d，为相似废水的处理提供参考。

关键词: 印刷电路板废水, 铜回收, 纳滤, 反渗透, 电沉积

Abstract:

The acidic cleaning wastewater generated during printed circuit board(PCB) manufacturing contains copper ions(Cu²⁺) at concentrations of 2-6 g/L. The recovery of these copper ions holds significant importance for promoting green development and achieving synergistic effects in pollution reduction and carbon mitigation within the PCB industry. The traditional treatment methods represented by chemical precipitation, ion exchange and adsorption are faced with three major problems in the process of treating PCB acidic cleaning wastewater including susceptibility to secondary pollution is easy to occur, serious waste of resources and low treatment efficiency. This study presented an innovative hybrid process combining physical concentration and chemical reduction-the “membrane concentration-electrodeposition” system. The front-end membrane concentration system employed nanofiltration to separate Cu²⁺ and Na⁺, followed by reverse osmosis and specialized separation processes that can concentrate Cu²⁺ up to 32 g/L. In the subsequent electrodeposition unit, selective reduction of Cu²⁺ was achieved under the condition of 500-900 A DC current, achieving a copper recovery rate>95% with a purity>99.5%. The direct economic benefit was 11 900 yuan/d, providing a valuable reference for the treatment of similar wastewater.

Key words: wastewater of printed circuit board, copper recovery, nanofiltration, reverse osmosis, electrodeposition

中图分类号: 

• X703