Photocatalytic discoloration of aqueous phenol red solutions using TiO2 nanocatalyst

In this paper, photocatalytic degradation of Phenol Red (PR) was evaluated in a slurry batch reactor using nano TiO2 (Degussa P-25) as a catalyst.The effect of the variation of different parameters, such as catalyst loading, initial PR concentration, inorganic salts and type of light sources on the rate of photocatalytic degradation was also studied, and the optimum conditions for the maximum degradation rate were determined. The photocatalytic degradation process was well described by pseudo-first order reaction.The optimum TiO2 loading, which provides enough surface area for reaction without irradiation loss due to scattering of UV light, was found to be 0.5 g/L, and PR concentration was 50ppm. Furthermore, the effects of inorganic salts were investigated. Result showed that photocatalytic degradation rate was affected significantly in the presence of nitrate and chloride.