抄録
A newly developed slurry-type titanium dioxide (TiO2) photocatalyst has been applied to the decomposition of pesticides in water. This photocatalyst is composed of the TiO2 nanoparticles deposited on the surface of a zeolite. Kinetic studies were performed on the photocatalytic decomposition using atrazine as the model pesticide. Reaction rate constants of 0.123, 0.161, and 0.512 min−1 for the TiO2 concentrations in the TiO2/zeolite complex of 0.025, 0.050, and 0.250 g/L, respectively, were obtained using an ultraviolet light source of 1 mW/cm2 at a wavelength of 350 nm. This showed that as the concentration of the TiO2 particles increased, the reaction rate constant also increased. In the prototype apparatus study, the concentration of atrazine in the treated water was maintained at 10 μg/L. Bubbling oxygen in the photoreactor was found to facilitate the decomposition of pesticides, indicating that the diffusion of oxygen gas on the TiO2 surface is the rate-determining step in the overall reaction process. The electric energy per order (EEO) under high oxygen concentration was 0.159 kWh/m3/order, which is comparable to other treatment methods.
