PH effect on decolorization of raw textile wastewater polluted with reactive dyes by advanced oxidation with U/VH2O2

The effectiveness of the advanced oxidation process (UV/H2O2) in decolorizing real textile wastewater polluted with commercial reactive dyes - Reactive Yellow 84 and Reactive Red 141 - was investigated. All the experiments were performed in a lab-scale reactor with the original high pH of the wastewater. The dyeing wastewater was decolorized in 5 hours. After its acidification to pH 3 the decolorization process was more efficient. Full decolorization was then achieved in 2 hours and the decrease in COD exceeded 70%. The reaction rate constants obtained were as follows: at pH 11.4, 0.0065 min(-1); at pH 7, 0.0044 min(-1), and at pH 3, 0.019 min(-1), which testified to pH importance for UV/H2O2 oxidation process.