Effects of operational parameters of process UV radiation/hydrogen peroxide on decolorization of anthraquinone textile dye

Abstract

The photodegradation of textile dye Reactive Blue 19, an anionic anthraquinone dye of reactive class, was investigated using UV radiation in the presence of H2O2 in UV reactor with low-pressure mercury lamps, with maximum energy output at the wavelength 254 nm. The effects of experimental variables, namely initial pH, initial dye concentration and concentration of peroxide were studied. The change of concentration of RB19 was followed by UV/vis spectrophotometric measurement of absorbance at 592 nm. The increase of the initial pH resulted in the efficiency increase of dye decolorization. The total decolorization was achieved in about 15 min. Results show that with the increase of dye concentration from 10 to 100 mg dm-3 the efficiency of process decreases. With the increase of the initial concentration of H2O2 from 10 to 30 mmol dm-3, the decolorization rate constant increased from 0.083 to 0.120 min1, with the decrease of process rate at the concentrations above. The highest decolorization rates were achieved at peroxide concentration of approx. 30 mmol dm-3, above which decolorization was inhibited by scavenging effect of peroxide. This study shows that UV/H2O2 process is promising treatment for dye RB 19 degradation in water and wastewater.