Photocatalytic Ozonation of Reactive Azo Dyes Using Zinc Oxide Photocatalyst

In this study، the photocatalytic ozonation of Reactive Red 2 (RR2) and Reactive Red 120 (RR120) in aqueous solutions under UV irradiation was investigated using ZnO as a photocatalyst. The effect of operating parameters such as catalyst dosage، pH،initial dye concentration and salt on the decolorization was studied. UV/vis spectrophotometric was used to assess dye decolorization. The results showed that the best pH value and ZnO dosage were 3 and 15 mmol/l، respectively. The dye decolorization enhanced with decreasing initial dye concentration. Sodium sulfate had no significant effect on dye decolorization process but sodium bicarbonate and sodium carbonate increased decolorization time. The results shown that the photocatalytic ozonation process was an effective method to degrade reactive dyes. J. Color Sci. Tech. 6 (2012), 19-25© Institute for Color Science and Technology.