The Optimization of Advanced Oxidation Processes for the Degradation of Industrial Pollutants

The suitability of advanced oxidation processes to industrial pollutants was evaluated. Three dyes were selected for research: Indigo carmine, Tartrazine, and Allura red AC. Single processes (oxidation by H2O2, Fenton process, ozonation), and hybrid processes (O3 + H2O2, O3 + Fenton) were applied. The results of the research obtained indicated that the use of hydrogen peroxide alone is not effective in the degradation of the analyzed dyes (max. efficiency was 9.38%). The use of the Fenton process (1 mg of Fe2+, 15 mu L of H2O2, pH = 3) allows for the complete decolorization of all dyes tested, while the time for each dye is different (2 min for Indigo carmine, 15 min for Tartrazine, and 30 min for Allura red AC). Ozonation is effective in removing only Indigo carmine. Thirty minutes of ozonation (pH = 5.5) results in a 97% elimination of this dye, while for Tartrazine and Allura red AC, the results were 8.46% and 4.32%, respectively. The addition of H2O2 and Fe(II) ions during ozonation accelerates the degradation of Indigo carmine (from 30 min to 1 min) and increases the elimination degree to approx. 80% of Tartrazine and Allura red AC. It has been proven that AOPs, for example, the Fenton process and ozonation, are sustainable in removing industrial pollutants, e.g., dyes.