STRUCTURE-DEPENDENT PHOTOCATALYTIC DEGRADATION OF POLYCHLOROBIPHENYLSIN A TIO2 AQUEOUS SYSTEM

Three positional isomers for each polychlorobiphenyl (PCB) homologous group tetra-, penta-, and hexachlorosubstituted were irradiated in a T iO2 (anatase) semiconductor aqueous suspension. Parent PCB disappearan ce was studied as a function of irradiation time, and a correlation be tween isomer substitution pattern and the photodegradative behavior wa s shown. In each group, the slowest disappearance trend was exhibited by the isomer with unsubstituted ortho positions, thereby capable of a dapting into a planar structural configuration with minimum (estimated ) energy requirement. In general, photodegradation rate increased with increasing degree of ortho chlorosubstitution. Copyright (C) 1996 Pub lished by Elsevier Science Ltd