Use of a NASA-developed ion exchange material for removal of zinc from electroplating baths

A new NASA-developed ion exchange material significantly reduces toxic metal effluent from rinse baths of electroplating facilities. The ion exchange material, originally developed as a battery separator for space applications, is a polymer made from polyacrylic acid and polyvinyl alcohol and converted to a calcium or sodium form. It exhibits a very high intake of metal ions such as zinc, cadmium, and copper, even in the presence of hard-water constituents. In this study, the adsorption efficiency for zinc was measured with a portable ion exchange system placed at the discharge end of a zinc plating line. The results show a significant reduction in the amount of zinc discharged into the sewer system.