Electroplating is the application of electroplating technology to coat metals or non-metals using electrochemical processes. In the electroplating industry, metals such as copper, nickel, chrome or zinc are applied to surfaces to protect them from corrosion, decorate them or improve their conductivity. The wastewater produced in electroplating often contains heavy metals and other pollutants that must be carefully treated before they can be discharged into the environment. Typical purification processes are precipitation, filtration and ion exchange.