The removal of reactive blue 181 in advanced oxidation processes with UV/H2O2

Synthetic dyes are commonly used in textile, dye, press and paper industries. Reactive dyes which used in textile industry, generate high quantities of organic pollution and wastewaters which contain colourful dyes at the end of the process. The most used advanced oxidation process are photocatalytic oxidation, hydrogen peroxide with ozone (O3/H2O2), ultraviole (UV), ultraviole with ozon (UV/O3), ultraviole with hydrogen peroxide (UV/H2O2), Fenton(Fe+2/ H2O2) and photo-fenton (Fe+2/ H2O2/UV). The effects of operating parameters, such as H2O2 dosage, pH value, dye concentration and temperature were examined. Maximum decolorization (99 %) efficiencies were achieved at the H2O2 dosage of 500 mg/l, dye concentration of 100 mg/l and pH 3 for 20 minutes reaction time. The decolorization kinetic of RB181 followed first and pseudo-first-order reaction kinetic. The paper also discussed thermodynamic parameters including enthalpy, entropy, for the decolorization of RB181 by UV/H2O2 and exposed that the oxidation process was exothermic under natural conditions.