氯化钾镉钴合金电镀废水的组合处理方法  

Combined process for treating potassium chloride cadmium–cobalt alloy electroplating wastewater

作　　者：郭崇武[1] 陈康[1] GUO Chongwu;CHEN Kang(Guangzhou Ultra Union Chemicals Ltd.,Guangzhou 510460,China)

机构地区：[1]广州超邦化工有限公司,广东广州510460

出　　处：《电镀与涂饰》2021年第2期115-118,共4页Electroplating & Finishing

摘　　要：在pH为10~12的条件下,先用亚铁离子和钙离子共同沉淀氯化钾镉钴合金电镀和钝化混合废水中的氨三乙酸等羧酸配位剂,六价铬被亚铁离子还原成三价铬后与镉离子、钴离子等一同生成氢氧化物沉淀。再用二甲基二硫代氨基甲酸钠沉淀废水中残留的重金属离子,使其沉淀完全。最后用次氯酸钠氧化废水中的电镀添加剂,降低其化学需氧量(COD)。该方法成本低,处理结果可满足GB 21900-2008《电镀污染物排放标准》的“表3”要求。Ferrous and calcium ions were used to precipitate the carboxylic acid coordinators such as nitrilotriacetic acid in the wastewater discharged from potassium chloride Cd-Co alloy electroplating and passivation at a pH of 10 to 12,during which the hexavalent chromium was reduced to trivalent chromium by ferrous ion and then precipitated with cadmium and cobalt as hydroxides.Sodium dimethyl dithiocarbamate was used to precipitate completely the residual heavy metal ions in the wastewater,and then sodium hypochlorite was used to oxidize the electroplating additives in the wastewater and reduce its chemical oxygen demand(COD).This method is cost-efficient and compliant with the Table 3 in the Emission Standard of Pollutants for Electroplating(GB 21900-2008).

关 键 词：镉钴合金电镀 钝化 废水处理 羧酸配位剂 螯合 沉淀 氧化 

分 类 号：TQ153.2[化学工程—电化学工业] X781.1[环境科学与工程—环境工程]