Photocatalytic decolorization of rhodamine B by immobilized TiO2/UV in a fluidized-bed reactor

The photocatalytic oxidation of Rhodamine B (RhB) was studied by using a newly developed immobilized photocatalyst (TiO2 immobilized by support consisting of a perlite and silicone sealant) and a fluidized-bed reactor. Three 8W germicidal lamps were used as the light source and the reactor volume was 2.8l. When this photocatalyst was employed in a batch process, a total decolorization of the RhB in reaction times lower than 60 min was observed. The optimum dosage of photocatalyst was 33.8 g/l. The initial RhB decolorization rate of the immobilized TiO2 was higher than that of the suspended TiO2 and this did not agree with pseudo first-order kinetics because of the adsorption onto the surface of the immobilized TiO2. This result indicated that the adsorption capacity of the immobilized photocatalyst is very important in photocatalysis.