电解法处理化学镀镍废液

Treatment of Spent Electroless Nickel Plating Bath by Electrolytic Method

目的研究电解法处理化学镀镍废液的可行性及处理效果．方法以泡沫镍为阴极、Ti基RuO2涂层电极作阳极电解回收废液中的镍．分析反应pH值、电流强度、温度、电解时间对电解效果的影响．结果控制pH=7～8，表观电流强度Ⅰ=0．45-0．5A，试验温度80℃、电解2h，可以使废液中镍的质量浓度从2018mg·L^-1降至53．7mg·L^-1，去除率高达97％以上．但随着镍离子质量浓度的降低，镍的单位时间去除率和电流效率下降，能耗增加很快．当镍离子质量浓度降至54mg·L^-1时，能耗升至9．9×10^5kJ．此外，经过2h的电解处理，废液中的总有机碳（TOC）的质量浓度可降低97．3％．结论利用电解法处理化学镀镍废液，不但可有效回收废液中的镍资源，还能去除废液中的大量有机物．但电解法应用也有局限性，不适于低质量浓度含镍废水的处理．

In this paper, the feasibility and efficiency of treatment of spent electroless nickel-plating bath by electrolytic method were studied. The influence of technology factors on the treatment together with the application limitations of the electrolysis was also investigated. The electrolysis cell, composed of a cathode （porous nickel foam） and an anode （Ti/RuO2 ）, was used to reclaim the nickel ion. Moreover, the effects of technological parameters on the electrolysis effectiveness were studied. Under the condition of 80 ℃, pH7 8,0.45 -0.5 A （current intensity） for 2 h,the concentration of nickel could be decreased from 2 018 mg· L^-1 to 53.7 mg· L^-1 with the removal rate more than 97%. However, when the concentration of nickel is low, nickel removal rate and current efficiency decreased rapidly together with higher energy expenditure. For example, when the concentration of nickel was reduced to 54 mg·L^-1, the energy expenditure would increase to 9.9 × 10^5kJ. Moreover, it is found that during the process of electrolysis ,the content of total organic compound （TOC） could be removed by 97.3 %. In conclusion, we can not only reclaim nickel resource but also remove many organic wastes in the wastewater by electrolysis method. But electrolysis method has its application limitation,that is, it can not be used to treat wastewater containing low concentration of nickel.