Photocatalytic Decolorization of an Azo Dye Derivative, Acid Yellow 29 in Aqueous Suspension of Titania

Photocatalyzed decolorization of an azo dye Acid Yellow 29 has been examined under UV -light irradiation by monitoring the change in absorption intensity as a function of irradiation time under a variety of conditions. The reaction was carried out in an immersion well photochemical reactor using titanium dioxide (TiO2) as photocatalyst. The effect of operating parameters such as catalyst type, catalyst quantity, substrate concentration, pH and electron acceptors (H2O2 and KBrO3,) on decolorization efficiency have been discussed. The photodecolorization of the dye Acid Yellow 29 was also examined under sunlight and the decolorization efficiency was compared with UV-light source. The maximum decolorization of the dye was observed at pH 3.2 with catalyst loading of 2.0 gL-1. Addition of KBrO3 as electron acceptor showed pronounced effect for the decolorization of the dye under investivation. Results demonstrated that the TiO2 mediated photocatalytic process can effectively decolorize Acid Yellow 29 under UV-light radiations.