© 2019, © 2019 International Ozone Association. The current study presents the treatment of water contaminated with the dye Direct Red 28 in the presence of Na2SO4 at three different concentrations (10, 40 and 80 g/L) by simple ozonation. This wastewater treatment was considered in a wastewater recycling process. At the end of each ozonation cycle, ozonation dynamics, ozone consumption, pH, electrical conductivity and UV/Vis spectra variation were analyzed and correlated with the stoichiometric analysis balance. The efficiency of the wastewater treatment in each reuse cycle was evaluated by a novel image processing method. The image results show that the presence of sulfate improves more than 45% the dye fixation on a cotton sample. However, at high additive concentrations, the color quality decreases 25%, compared with the system with low additive concentration, due to the presence of peroxysulfate ions and the compounds accumulated through the ozonation process.