Evaluation of UV/H2O2 advanced oxidation process (AOP) for the degradation of diazo dye Reactive Green 19 in aqueous solution

The azo dye Reactive Green 19 (RG19) is extensively used for dyeing textiles due to its cost effectiveness and excellent fastness properties. Treatment of wastewaters containing this dye by conventional methods is often inadequate because of its resistance to biological and chemical degradation. In this study, the suitability of an advanced oxidation process based on the use of UV radiation and hydrogen peroxide to degrade RG19 was investigated. Analysis of degradation data showed that the decolorization process followed pseudo-first-order kinetics. The existence of an optimum pH and H2O2 dose was also observed. Under the best conditions, complete decolorization of the dye solution was achieved in about 20min. Total organic carbon (TOC) measurements showed that mineralization was slower than decolorization, but over 63% of TOC was removed in 90min. Overall, the results obtained indicate that the UV/H2O2 treatment can be an effective method for the removal of RG19 from textile effluents.