Background: The discharge of textile industrial wastewater, a complex effluent containing different chemicals, to the environment causes serious bioenvironmental pollution problems. Therefore, this study aimed to evaluate the use of advanced oxidation methods and find the most efficient method to remove dye from textile effluents.

Materials and Methods: This experimental study was conducted on Kashan textile industrial effluent on a laboratory scale and in a closed system. Taking into consideration the fixed amount of O3 dose and H2O2 concentration for the four advanced oxidation methods (UV/O3, UV/H2O2, H2O2/O3, O3/UV/H2O2), in three reaction time (10, 20, 30 minutes) and different pH (4, 6, 8, 10), the effect of the methods on dye removal was evaluated and the results were compared using the complex repetitive measurements.

Results: Results showed that, in terms of method used and the contact time, the O3/UV/H2O2 method in 30 minutes had the most efficient result (89.2%) and the UV/H2O2 method in 10 minutes time the least one (40.7%). Moreover, in terms of the method used and pH, the O3/UV/H2O2 method in pH=6 had the most efficient result (84.7) and the UV/H2O2 method in pH=4 the least one (59.4). The results showed that time had a positive effect on dye removal efficiency (P<0.001).

Conclusion: The O3/UV/H2O2 method is the most efficient method in removing dye from textile wastewater due to the synchronous presence of multi-pollutants and its synergic effect through producing the highly reactive hydroxyl radicals (OH0).