Dye decomposition kinetics by UV/H 2O 2: Initial rate analysis by effective kinetic modelling methodology

Abstract

The wastewater from textile industries containing non-biodegradable and toxic dye compounds is one important sources of environmental contamination. This study aims at investigating the decomposition of azo dye by UV/H 2O 2 process with varying H 2O 2 concentrations, dye concentrations, initial pHs, and UV irradiation powers. The results show that the initial rate increases with increase in initial H 2O 2 concentration, initial dye concentration to a certain point and then decreases with further increase in the above factors; the initial rate remains almost constant at lower pH and then decreases with increase in pH; the initial rate linearly increases with increase in UV irradiation power. A comprehensive kinetic model, based on reaction network analysis, was developed to predict the effects of H 2O 2 concentration, dye concentration, solution pH, and UV irradiation power on the initial dye reaction rate. The experimental data and the predicted results are in good agreement.