在pH = 8 ~ 13的条件下,用双氧水破坏碱性锌镍合金电镀废水中的羟基羧酸类配位剂.接着调节废水的pH至4.5 ~ 5.5,令脂肪族多胺类配位剂的配位能力降低.然后加焦亚硫酸钠还原废水中残留的双氧水,再以二甲基二硫代氨基甲酸钠螯合沉淀锌和镍离子.当电镀废水中脂肪族多胺的质量浓度不高于于2.5 g/L时,锌和镍的出水浓度满足GB 21900-2008《电镀污染物排放标准》的"表2"要求;当脂肪族多胺低于0.5 g/L时,锌和镍的出水浓度满足GB 21900-2008的"表3"要求.%The hydroxycarboxylic acid complexing agent in the wastewater discharged from Zn-Ni alloy electroplating process is oxidized by H2O2 at pH 8-13. The pH of the wastewater is then adjusted to 4.5-5.5, decreasing the complexing power of aliphatic polyamine. The remaining hydrogen peroxide is reduced by sodium metabisulfite, and the Zn and Ni ions are precipitated by chelation with sodium dimethyldithiocarbamate. The effluent Zn and Ni concentrations meet the requirement of the Table 2 stipulated by the Emission Standard of Pollutants for Electroplating(GB 21900-2008)when the influent mass concentration of aliphatic polyamine is not higher than 2.5 g/L,and even are compliant with the Table 3 of GB 21900-2008 when the mass concentration of aliphatic polyamine is lower than 0.5 g/L.
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