PHOTODEGRADATION OF SURFACTANTS .13. PHOTOCATALYTIC MINERALIZATION OFNITROGEN-CONTAINING SURFACTANTS AT THE TIO2 WATER INTERFACE

The catalyzed photodecomposition of the cationic surfactants benzyltet radecyldimethyl ammonium chloride (BTDAC) and N-dodecyl pyridinium chl oride (DPC), together with their model analogues, has been examined in aqueous TiO2 suspensions. The process leads to cleavage of the benzyl or pyridinium rings, and the formation of ammonium and nitrate ions, and yields the ultimate mineralization product CO2. Photodegradation o f the nitrogen function to the ammonium ion appears to predominate ove r photooxidation to nitrate ions. Cationic surfactants that possess an aromatic moiety are more easily photoreduced than those systems with alkyl chains only.