Investigation of plating wastewater treatment technology for chromium, nickel and copper

Abstract

Electroplating during chrome, nickel and copper production generates a large amount of wastewater, with plating wash water, plant wash water and equipment cooling and wash water comprising the main sources of wastewater. These wastewaters contain a variety of metal components, which causes the concentrations different. Metal ions can cause serious harm to humans, animals, plants and the environment; therefore, it is necessary to treat electroplating wastewater to remove these materials. Electroplating wastewater also contains a large number of complexes that are difficult to remove by simple precipitation. In this study, the iron reduction co-precipitation method was found to remove hexavalent chromium, decompose nickel and copper complexes and reduce chemical oxygen demand (COD) well. The average chromium-nickel-copper ion concentration was stable at 0.1 ppm, while the COD was stable between 20 and 30 ppm, enabling rapid processing by one-time treatment to meet the emission standards of China.