Synergistic Effect of H2O2 Addition on Gamma Radiolytic Decoloration of Some commercial Dye Solutions

Abstract

Gamma radiations have emerged as a potential tool to degrade and decolorize the industrial effluents containing synthetic dyes in eco friendly and efficient manner. The dose and exposure time required to achieve the efficient decolration are quite high using gamma radiations alone during gamma radiolysis of synthetic dyes. Studies have revealed that, it can be brought down significantly on addition of H2O2 as it enhances the degree of decoloration. This happens due to the formation of highly oxidizing •OH radicals that are formed due to rapid reaction of H2O2with hydrated electrons formed during radiolysis of water. Further as the dose of H2O2 increases, extent and rate of decoloration also increases up to a certain value referred to as critical dose. But further increase in dose of H2O2 beyond this critical value affects the extent of decoloration adversely. In present communication, the gamma radiation induced decoloration of Methylene Blue, Malachite Green and Indigo Carmine dyes was achieved using various doses of H2O2. It was observed that, the value of H2O2 Critical dose required for efficient decoloration varies from dye to dye indicating its dependence on structure and concentration of dye solutions.