The composition of electroplating wastewater is very complex. In addition to cyanide containing (CN -) wastewater and acid-base wastewater, heavy metal wastewater is a potentially hazardous category of wastewater in the electroplating industry. According to the classification of heavy metal elements contained in heavy metal wastewater, it can generally be divided into wastewater containing chromium (Cr), wastewater containing (Ni), wastewater containing (Cd), wastewater containing (Cu), wastewater containing zinc (Zn), wastewater containing gold (Au), wastewater containing silver (Ag), etc.