Comparative Evaluation of UV / Solar Light Induced Photode gradation of Azo Dye in Aqueous Solutions

Abstract

In present study, photocatalytic degradation of Acid Orange 7 (AO7), an anionic dye has been investigated in a batch reactor using titania P-25 (surface area: 50 m2/g) as a photocatalyst under UV/Solar light in slurry mode. The variables studied include catalyst dose, solution pH and dye concentration. The degradation rate of AO7 was favorable at pH 2. Optimum value of catalyst dose was found to be 1g/l. The disappearance of AO7 obeyed first order kinetics and the value of the rate constant k was 1.1 X 10^-4 S^-1. COD analysis revealed the mineralization of AO7 on TiO₂ surface. The complete degradation of AO7 was achieved in 15 h under UV irradiation, whereas under solar light, AO7 was degraded completely in 55 minutes only.