Study of Efficiency of Photochemical Oxidation Process with UV/Peroxidisulfate for Removal of Alizarin Red S from Aqueous Solutions

Introduction and purpose: Treatment of dye wastewater produced bytextile industries is a major challenge for the environment. About 15% of thetotal produced dyes in the world are released in sewages during dyeing activities.Alizarin red S (ARS), a synthetic dye produced from Alizarin sulfonate is themost widely used dye in the textile industry. The aim of this study was to removeARS dye from aqueous solutions through advanced photochemical oxidationprocess using UV/peroxidedisulfate.Methods: In this study, the effect of pH, concentration of persulfate, dyeconcentration, and UV radiation on removal of ARS were studied in laboratoryscale using a reactor containing UV-C lamp (6 watts) by batch method. ARSconcentration was determined by UV/Visible spectrophotometer.Results: The results showed that removal efficiency increased by increasingthe disulfate concentration, ultraviolet radiation intensity, and reaction timeand decreased by increasing dye concentration and pH. The optimum conditionwas obtained at pH=7, peroxidisulfate concentration of 0.02 Mmol/L, and 50mg/L dye concentration. Also, the ARS removal by UV/peroxidisulfate processfollows a first-order kinetic.Conclusion: Due to the high removal efficiency of this process in removing ARS(96.5%), use of this process can be a good choice in the treatment of dye andindustrial wastewater.