Degradation kinetics of azo dye reactive Red SBE wastewater by complex ultraviolet and hydrogen peroxide process



UV/H2O2 was applied to deal with azo dye Reactive Red SBE (RR SBE) in aqueous and effects of hydrogen peroxide dosage, initial dye dosage, pH value, and different anions on color removal were investigated in detail. The online spectrophotometric method was used to detect the change dye absorbance at different reaction time. The results show that RR SBE can be completely decomposed in less than 40 min with 4.412 mM H2O2 dosage, initial dye 17 mg L−1 and neutral ambient. The RR SBE degradation performance follows pseudo first order kinetics and the reaction rate constant of ·OH and RR SBE is 2.32 × 109 M−1 s−1 that is estimated by UV/H2O2 kinetic model. The anions inhibiting effect on dye decolorization follows the order of PO43− > CO32− > Cl > SO42− > HCO3 > HPO42−. The main intermediate product is phthalic acid dimethyl ester after UV/H2O2 degradation and possible decomposition mechanism of RR SBE is predicted by GC-MS analysis. © 2010 American Institute of Chemical Engineers Environ Prog, 2011