Design of two types of fluidized photo reactors and their photo-catalytic performances for degradation of methyl orange

To enhance the performance for organic compound destruction in a photo-catalytic system, fluidized reactors of two types were manufactured and methyl orange was destroyed using these reactors. The TiO2 colloidal solutions used for a catalyst film and powder were obtained by the sol-gel method. The TiO2 film, which was dip-coated on slide glass, was characterized by XRD and SEM analyses. The TiO2 catalysts exhibited an anatase structure with particle size around 50 nm after thermal treatment at 500degreesC for I h. In particular, the film could be stably fixed on a substrate. To investigate the destruction performance of methyl orange, fluidized bed reactors of two types were designed for the reaction. One is the film photo system that was directly fixed on the UV-lamp with TiO2 colloidal solution by the dip-coating method, and the other is the 0.1 wt.% powder photo system added directly to the reactant solution. The methyl orange in TiO2 film photo system was remarkably decomposed compared with that of TiO2 anatase powder photo-system; the conversion reached 100% after 4 h in air bubbling of 500 ml/min in the TiO2 film photo system with five-coatings. Otherwise, the methyl orange remained for 5 h in the 0.1 g/l TiO2 powder photo system. These results confirmed that the VOC removal was more useful in the film photo system than in the powder photo system. (C) 2002 Elsevier Science B.V. All rights reserved.