Photodegradation of methylene blue dye using UV/BaTiO3, UV/H2O2 and UV/H2O2/BaTiO3 oxidation processes

The photocatalytic degradation of methylene blue (MB) in aqueous solution was studied using UV source in presence of synthesized BaTiO3 as photocatalyst and in combination with different concentrations of H2O2. The experiments were carried at different catalyst loading (0.05 & 0.1 wt %), pH (3, 7 & 9) and H2O2 dosage (0.5 - 6 mL/L). The degradation rate was found to be strongly dependent upon various experimental parameters such as catalyst loading, pH, and dosage of H2O2. There was no appreciable degadation seen in presence of catalyst alone. Discoloration of the dye was very nearly complete using UV/H2O2. Neither UV radiation nor H2O2 alone was able to decolourize the dye. The best degradation results were observed under optimum conditions of catalyst loading of 0.05 wt%, pH 9 for BaTiO3/UV system. The optimum dosage of H2O2 for 12 ppm concentration of the dye was found to be 2 mL/L for UV/H2O2. The experimental kinetic data on the degradation of the dye followed the pseudo first order rate. Tests were further carried out for degradation of the dye using BaTiO3/UV/H2O2 system. An enhancement in the degradation rate was observed with this system compared to UV/H2O2 system.