Decolorization and Mineralization of Cationic Dye (Crystal Violet) by Several Photochemical Methods

The aim of this study is to test the ability of some photochemical processes advanced oxidation processes (AOPs) such as: UV/H2O2, UV/S2O82 to eliminate dye in aqueous solution. The efficiency of substrate decolorization and mineralization in each process has been comparatively discussed by decreases in concentration and total chemical oxygen demand content of CV solutions. The obtained results showed that system like: H2O2/UV and S2O82- /UV were better than direct UV photolysis at. 254 nm and acetone/UV at the same wavelength. This improvement seems to be linked to production of OH center dot and SO4 center dot- radicals issued from the photolysis of H2O2 and S2O82-, always at this same wavelength. The most efficient method on decolorization and mineralization was observed to be UV/H2O2 process. Mineralization efficiency was observed in the order of UV/H2O2> UV/S2O82. Final solutions of AOPs applications after treatment can be disposed safely to environment. The degradation rate is strongly dependent on the initial concentrations of the H2O2 and S2O82-. The effect of these parameters has been studied and the optimum operational conditions of these processes were found.