What is wrong with chrome plating?
Chrome plating has been in use since the 1940s and is a powerful, simple and cheap process. The plating solution is very simple (chromic acid, sulfuric acid, and sometimes brighteners and other additives) and the process is quite forgiving. Unfortunately chromic acid means lots of hexavalent chrome (Cr6+), and the process is quite inefficient, with most of the current going to hydrolyze the water, producing copious amounts of hydrogen and oxygen bubbles. When they rise to the surface these bubbles burst, throwing a fine mist of hexavalent chrome into the air. To protect workers and the environment, this mist has to be sucked away in an efficient air-handling system. Chrome plating generates several different waste streams: • Cr6+ mist air emissions worker health and safety issue in the plant, air pollution issue outside, must be trapped in scrubbers • Cr6+-contaminated waste water must be treated before release to public treatment plants or water courses • Solid wastes must be disposed
