Electroplating Copper-nickel Alloy Wastewater Of Copper, Nickel Ion Removal

This paper will focus on the research of rinsing water of Cu-Ni alloy plating. Plenty of complex agents are added in the alloy plating, which makes solubility of copper(II) and nickel(II) rise and therefore, ions difficult to deposit. According to this feature, the paper discusses some possible solution. Although the method of realizing ion deposition by decomplexation is feasible in theory, the technology is difficult to put into practice and demands high cost. Therefore, this paper focuses on the treatment schemes that firstly remove metal ions according to National Emission Standard, secondly discharge the waste water which include complex agents into biochemical pool for decomplexation aswell as other organic compounds, and eventually discharge up to the COD standard.Because copper (II) and nickel (II) ions in the waste water can not turn into hydroxid by adjusting pH value if the waste water includes citric acid, triethanolamine or some other organic compounds, we must use special chemical to decomplex metal ions from complex agents which include citric acid and triethanolamine, and then move into next step. So by using polyamidoamine and CS₂, we make formate disulfide - amine compound (called metal ions precipitants in this paper), whose feature are as follows: 1) It has dithio group, which can decomplex metal ions from complex agents; 2) There are hydrophobic organic group, which doesn't dissolve in water after complex with metal ions; 3) The molecular weight of precipitants is big. Besides, one precipitant molecule can complex several metal ions, and has flocculability, which can make deposit easy to separate.The three new heavy metal ions precipitants mentioned in this paper can be used to treat heavy metal ions of medium complex property. The result of experiments shows that the three new heavy metal ions precipitants mentioned in this paper can effectively remove heavy metal ions of Cu-Ni alloy plating, and the complex of formate disulfide and polyethylidene imine is most useful. If using the complex to treat waste water of Cu-Ni alloy plating for 5 minutes on the condition that pH value is approximately 8, we can make the content of heavy metal ions up to National Emission Standard. This technology is easy to approach, convenient for addition, and with no secondary pollution, so has wide application prospect.