Ozonation (O3) and AOP involving O3/H2O2 have been considered as an emerging technology for degradation of dyes in textile and dyestuffs industrial effluent. However, the comparative performance of these processes for dye removal is remains unclear. Therefore, the performance of O3 and O3/H2O2 processes for azo dye removal in industrial effluent was evaluated in this study. The specific objectives of the research are to compare the performance of O3 and O3/H2O2 processes for colour, COD and TOC removal, and to evaluate the effect of initial concentration and initial pH on the performance of O3 and O3/H2O2 processes. The dyes used were Reactive Black 5 (RB5), Remazol Brilliant Blue (RBB), Reactive Green 19 (RG19) and Reactive Red 120 (RR120). The experiments of O3 and O3/H2O2 processes were conducted in a semibatch reactor originated from cylindrical glass reactor. The result shows that the colour removal of RB5, RBB, RG19 and RR120 in O3/H2O2 treatment was slightly higher than O3 treatment for ozonation time less than 5 minutes and the comparison value approximately only 0.5 %. Moreover, complete colour removal was achieved for ozonation time more than 5 minutes in both processes. The significant removal efficiency of both O3 and O3/H2O2 processes showed that both processes are efficient for colour removal of reactive dyes.
