AOX are adsorbable organic halogen compounds. They are formed when waste water containing organic substances (even in minute quantities) is oxidized by chlorine-containing oxidizing agents. These can be adsorbed again by activated carbon. This process does not solve the problem of waste disposal, it is only shifted to the waste side.
In electroplating, the main component of AOX is chloroform, which occurs during the oxidation of cyanides with hypochlorite.