ABSTRACT
The metal nishing industry uses a variety of physical, chemical, and electrochemical processes to clean, etch, and plate metallic and nonmetallic substrates. Chemical and electrochemical processes contribute more to the generation of hazardous waste than do physical processes, such as blasting, grinding, and polishing. The chemical and electrochemical processes are performed in numerous chemical baths, which are followed by rinsing operations. The most common wastes generated by the metal nishing industry are rinse water efuent and spent process bath chemicals. Typically, rinse water efuent and spent process bath chemicals are treated on-site before being discharged to a local publicly owned treatment works (POTWs).
