Photocatalytic degradation of aqueous propoxur solution using TiO2 and Hβ zeolite-supported TiO2

Photocatalytic activity of TiO2 and zeolites supported TiO2 were investigated using propoxur as a model pollutant. HP, HY and H-ZSM-5 zeolites were examined as supports for TiO2. HP was chosen as the TiO2 support based on the adsorption capacity of propoxur on these zeolites (HP > HY = H-ZSM-5). TiO2/H beta photocatalysts with different wt.% were prepared and characterized by XRD, FT-IR and BET surface area. The progress of photocatalytic degradation of aqueous propoxur solution using TiO2 (Degussa P-25) and TiO2 supported on HP zeolite was monitored using TOC analyzer, HPLC and UV-vis spectrophotometer. The degradation of propoxur was systematically studied by varying the experimental parameters in order to achieve maximum degradation efficiency. The initial rate of degradation with TiO2/H beta was higher than with bare TiO2. TOC results revealed that TiO2 requires 600 min for complete mineralization of propoxur whereas TiO2/H beta requires only 480 min. TiO2/HP showed enhanced photodegradation due to its high adsorption capacity on which the pollutant molecules are pooled closely and hence degraded effectively. (C) 2008 Elsevier B.V. All rights reserved.