Patent ID: 11136254

Abstract:
A method for integrated treatment of electroplating wastewater includes steps of: adjusting and maintaining pH of wastewater at 10.5-12; oxidizing pollutants such as sodium cyanide and hydroxyl-containing organic amine complexants with sodium hypochlorite; precipitating carboxyl-containing organic acid complexants with synergistic effect of ferrous and calcium ions; reducing hexavalent chromium to trivalent chromium and forming chromium hydroxide precipitate; removing precipitate by filtering; adjusting wastewater to pH of 4.5-5.5; precipitating heavy metal ions with sodium dimethyldithiocarbamate or sodium diethyldithiocarbamate; adsorbing precipitate and heavy metal capturing agents with activated carbon; filtering to remove precipitate; adjusting wastewater to pH of 6-8; and destroying aliphatic polyamine complexants and reducing COD using an available biological degradation technique. This method can effectively and economically remove the pollutants such as heavy metals in the electroplating wastewater for a good market prospective.