氯化钾无氰镀镉和钝化混合废水的处理工艺  

Process for treating the mixed wastewater discharged from potassium chloride cyanide-free cadmium plating and passivation

作　　者：黎小阳 郭崇武[1] LI Xiaoyang;GUO Chongwu(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》2020年第9期570-572,共3页Electroplating & Finishing

摘　　要：用二甲基二硫代氨基甲酸钠沉淀氯化钾无氰镀镉和钝化混合废水中的镉离子。在p H为10~12的条件下用亚铁离子和钙离子共同沉淀氨三乙酸等羧酸配位剂,从配合物中释放出的三价铬离子与二甲基二硫代氨基甲酸钠反应生成沉淀物,亚铁离子将六价铬还原成三价铬并生成沉淀物。然后用次氯酸钠破坏废水中的电镀添加剂,降低化学需氧量(COD)。该处理工艺简单,成本低,出水能满足排放要求。A process for treating potassium chloride cyanide-free cadmium plating and passivation wastewater was developed. The cadmium ions are precipitated using sodium dimethyldithiocarbamate. The carboxylic acid coordinators such as nitrilotriacetic acid are precipitated with ferrous and calcium ions at pH 10-12, the trivalent chromium ions released from the complexes are reacted with sodium dimethyldithiocarbamate to form precipitates, and the hexavalent chromium is reduced by ferrous ion to trivalent chromium which is formed a precipitate further. The electroplating additives are destroyed by sodium hypochlorite, reducing the chemical oxygen demand(COD) in the wastewater. The process has advantages of simple operation and low cost, and the effluent is compliant with the emission standard.

关 键 词：氯化钾无氰镀镉 铬酸盐钝化 废水处理 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]