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. | Science & Technology Development, Vol 19, Effects of gamma irradiation on color removal from reactive red 24 aqueous solutions Ha Bui Manh Department of Environmental Sciences, Sai Gon University Duy Nguyen Ngoc Hien Nguyen Quoc Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute (Received 15 February 2016, accepted 11 April 2016) 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. Keywords: Decolorization, gamma irradiation, reactive red 24, textile wastewater. 1. INTRODUCTION Reactive dye-containing wastewater is one of the most difficult wastewater to treat, because most of reactive dye has complex chemical structures with high water-solubility. Moreover, the dye structures are commonly highly resistant to biodegradation process. chemical coagulation, photodegradation, membrane, ozonation, sonolysis, etc. [1-3]. Nonetheless, most of these techniques are limited by technology, cost or difficulties in operation. Hence, they could not be employed to treat real dyeing wastewater. One of the
