The effect of operational parameters on UV/H2O2 decolourisation of Acid Blue 74

In the present study, advanced oxidation treatment, the UV/H2O2 process was applied to decolourisation of the indigoid dye C.I. Acid Blue 74 in aqueous solution. The UV radiation was carried out with a 15 W low-pressure mercury lamp. The rate of colour removal was studied by measuring of the absorbency at characteristic wavelength. The effects of H2O2 dosage, dye initial concentration and pH on decolourisation kinetics in the continuous circulation photoreactor were investigated. The highest decolourisation rates were observed at pH range between 3.5 and 5.5. The optimal levels of H2O2 needed for the process were examined. It appears that high levels of H2O2 could reduce decolourisation by scavenging the OH. The colour degradation rate decreases as the dye concentration increases.