Influence of operational parameters on photocatalytic degradation of a genotoxic azo dye Acid Violet 7 in aqueous ZnO suspensions

The photocatalytic degradation of a genotoxic azo dye Acid Violet 7 (AV 7) using ZnO as a photocatalyst in aqueous solution has been investigated under UV irradiation. The degradation is higher with UV/ZnO process than with UV/TiO(2)-P25 process at pH 9. The effects of different parameters such as pH of the solution, amount of catalyst, initial dye concentration and the influence of cations, anions and oxidants on photodegradation of AV 7 were analyzed. Addition of oxidants except H(2)O(2) has no significant effect on degradation. The degradation of AV 7 follows pseudo-first order kinetics according to the Langmuir-Hinshelwood model. The degradation of AV 7 has also been confirmed by COD and CV measurements.