Decolorization of antraquinone dye Reactive Blue 181 solution by UV/H2O2 process

•A high decolorization efficiency of 99% for RB181 was achieved after 20 min treatment with UV/H2O2 process.•Decolorization of RB181 depends on pH, H2O2 dose and dye concentration.•The decolorization kinetic of RB181 followed pseudo-first-order reaction kinetic.•The decolorization of RB181 by UV/H2O2 and exposed that the oxidation process was exothermic under natural conditions.

In this study, the decolorization of C.I. Reactive Blue 181 (RB181), anthraquinone dye, by UV/H2O2 processes was investigated. The effects of operating parameters, such as H2O2 dosage, pH value, dye concentration and temperature were examined. The optimum conditions were determined as [H2O2] = 500 mg/L, [RB181] = 500 mg/L and pH 3 for 20 min reaction time. The decolorization was achieved by the UV/H2O2 process because of the production of some oxidizing agents as a result of UV irradiation. The decolorization kinetic of RB181 followed pseudo-first-order reaction kinetic. Thermodynamic analysis showed negative values of ΔH indicating exothermic under natural conditions.

Graphical abstractThe UV–vis spectra of RB181 during its decolorization of 20 min.Figure optionsDownload full-size imageDownload as PowerPoint slide