Abstract: Photochemical method using UV/H2O2 was utilized to decolourize CI Reactive Red 195A. In this work, the UV radiation source was a low-pressure mercury arc lamp (60W emitting at 253.7nm). Using the combined UV/H2O2 process, the effects of initial hydrogen peroxide dosage, dye concentration, pH and temperature were examined to determine the optimum operating conditions of the treatment process. Complete decolourization of 100 mg/L dye was achieved in the relatively short time of 20-30 minutes irradiation. Faster decolourization was achieved at low pH and high temperature. The removal rate increased with increasing initial concentration of H2O2 up to an optimum value (approximately 900 mg H2O2/L). However, even after near complete removal of the active dye from the solution, approximately 60% of the COD was still remaining, indicating only partial breakdown of the dye molecule. In general, the result indicates that the UV/H2O2 technology has a good potential for removing dyestuff from wastewater, but additional treatment is required to achieve further degradation of the organic intermediates and possibly reduce the UV irradiation time and chemical consumption.
Keywords: Decolourization, Photochemical, Reactive azo-dye, Textile, UV/H2O
