膜工艺在电镀废水处理工程中的应用

Application of membrane technology in electroplating wastewater treatment projects

运用先进的膜分离技术,可以实现电镀废水的深度处理和资源化利用。基于近年内建成运行的3个工程实例,分析和讨论了膜技术在电镀废水处理中的应用及其效果。结果表明:结合常规废水处理工艺与膜生物反应器(MBR)组合工艺,电镀废水被处理后水质达到排放标准;电镀综合废水经超滤(UF)净化、反渗透(RO)和纳滤(NF)两段脱盐膜的集成工艺处理后,水质达到回用水标准,RO和NF产水水质电导率分别低于约100和1 000μS/cm,COD分别为约5和10 mg/L;镀镍漂洗废水通过RO膜后,镍的浓缩倍数高达25倍以上,实现镍的回收,RO产水水质达到回用标准。投资与运行费用分析表明:工程运行1年多即可收回RO浓缩镍的设备费用。此3项不同工艺处理电镀废水的工程实例,为进一步开展膜技术治理工业废水提供了成功案例。

The advanced treatment of electroplating wastewater and its reclamation can be achieved by applying the advanced membrane separation technology. In this study,the application of membrane technology in the treatment of electroplating wastewater and its efficiency were analyzed and discussed based on the three projects accomplished and put into operation in recent years. The results showed that the electroplating effluent from the membrane bioreactor（ MBR） combined with the conventional wastewater treatment processes could meet the stringent discharging standards; the integrated membrane technology with ultrafiltration（ UF）,reverse osmosis（ RO）and nanofiltration（ NF） was applied to reuse the electroplating wastewater. It was found that the electrical conductivity of desalination water from RO and NF process were all less than 100 μS / cm and 1 000 μS / cm,and the COD values were about 5 mg / L and 10 mg / L,respectively. The rinse wastewater from nickel-plating industry can be treated by RO process,in which nickel was recovered with the concentration times of above 25,and the permeate water of RO reached the standard of reused water as well. The cost analysis of investment and operation also indicated that the payback period of the expenses on RO equipment for nickel concentration was little more than one year. These three different projects of electroplating wastewater treatment provide the successful examples for the further development of industrial wastewater treatment by membrane technology.