Integration and Application of Zero Discharge Techlonogy for Electroplating Wastewater

Abstract

Containing not only heavy metal ions like Cr，Ni, Cu and Cd, but also pollutants like cyanide and phosphate, electroplating wastewater is a strong pollution. So, how to solve the pollution problem of electroplating wastewater is crucial for the development of electroplating industry. The integration and application of zero discharge technology for electroplating wastewater were analyzed and discussed based on the actual case of a machine tools factory. The electroplating wastewater was separated based on quality and treated with a chemical pretreatment separately to meet the discharge requirements, and then concentrated through three stages: the first stage RO, the second stage RO, and third state DTRO. Finally, the concentrated liquid was evaporated and crystallized by the evaporator, and the water produced in RO stage was reused by the production line. Thus the wastewater was completely reused with an accepatble operating cost. It was concluded that a zero discharge of electroplating wastewater was feasible and could be promoted.

Keywords

• electroplating wastewater|zero discharge|pretreatment|evaporation crystallization