Method for treatment of mixed electroplating wasterwater without cyanide and phosphorus-containing reductant

A method for treatment of mixed electroplating wastewater without a cyanide and a phosphorus-containing reductant without a cyanide and a phosphorus-containing reductant. A ferrous chloride solution is added into electroplating wastewater without a cyanide and a phosphorus-containing reductant. The pH of wastewater is adjusted to 10.5-12. Pollutants such as sodium cyanide and hydroxyl-containing organic amine complexants are oxidized with sodium hypochlorite. Carboxyl-containing organic acid complexants are precipitated. Hexavalent chromium is reduced to trivalent chromium to form chromium hydroxide precipitate. Precipitate is removed by filtering and wastewater is adjusted to pH 4.5-5.5. Heavy metal ions are precipitated with sodium dimethyldithiocarbamate or sodium diethyldithiocarbamate. Precipitate and heavy metal capturing agents are adsorbed with activated carbon followed by removal of precipitate. Wastewater is adjusted to pH 6-8. Aliphatic polyamine complexants are destroyed using an available biological degradation technique to reduce chemical oxygen demand.