An easy and efficient use of TiO2 supported HZSM-5 and TiO2+HZSM-5 zeolite combinate in the photodegradation of aqueous phenol and p-chlorophenol

Titanium(IV) oxide of 2, 5, 10, and 15 wt.% was supported on HZSM-5 zeolite using solid state dispersion (SSD) method. These catalysts were characterized by BET surface area, XRD, UV-VIS-DR-spectra and SEM-EDAX. Characterization of TiO2/HZSM-5 (SSD) catalysts clearly shows that TiO2 dispersed in solid state is free of interaction with the zeolite. The photocatalytic activity of these systems in the degradation of aqueous phenol and p-chlorophenol indicates that TiO2/HZSM-5 (SSD) is an active photocatalyst; the optimum photodegradation activity is seen at 10-15 wt.% TiO2/HZSM-5. The same activity is also achieved by simply suspending TiO2 + HZSM-5 combinate (mechanical mixture) in aqueous phenol and p-chlorophenol. Based on these results, a model highlighting the photodegradation activity of both immobilized [TiO2/HZSM-5 (SSD)] and mobilized [TiO2 + zeolite (combinate)] TiO2, Which may lead to the development of an easy and effective technology in wastewater treatments, is proposed. (C) 2002 Published by Elsevier Science B.V.