Effects of gamma irradiation on color removal from reactive red 24 aqueous solutions

Abstract

Decolorization from synthetic wastewater containing Reactive Red 24 (RR24) using gamma Cobalt-60 ray was investigated. The influence of the irradiation dose, initial pH, initial dye and hydrogen peroxide (H₂O₂) concentration were evaluated. The pH effect has proved that lower decolorization efficiency was observed in alkaline medium as compared to the neutral and acid medium. While color removal efficiency increased with increasing absorbed dose. A synergistic effect of gamma radiation with H₂O₂ was applied and the results showed that H₂O₂ accelerated decolorization process, however when the dosage of H₂O₂ exceeded the optimal concentration, the color removal efficiency attained saturation and even reduced. The color removal efficiencies achieved over 99% at the dose of 4 kGy, initial pH 7, initial dye concentrationof 100 mg/L and H₂O₂ concentration of 3mM. These results highlighted the potential of radiation technology for dye removal from textile wastewater.