A comparative study on the decolorization of Tartrazine, Ponceau 4R, and Coomassie Brilliant Blue using persulfate and hydrogen peroxide based Advanced Oxidation Processes combined with Hydrodynamic Cavitation

Decolorization of Ponceau 4R, Tartrazine, and Coomassie Brilliant Blue (CBB) was studied using hybrid processes of hydrodynamic cavitation (HC) with potassium persulfate (KPS) and hydrogen peroxide (H2O2). The different properties of these dyes such as hydrophobicity, molecular structures, and molecular weights provided this opportunity to investigate the effects of these factors by comparing the decolorization values of the dyes. Treatment process was optimized in respect to cavitation number, HC inlet pressure, and the concentration of external oxidants. The application of dual oxidation system under cavitation conditions revealed a synergetic effect. Maximum decolorization values of 92.27%, 50.1%, and 42.3% were obtained applying this combined process for CBB, Tartrazine, and Ponceau 4R, respectively. The different values of decolorization of the dyes were explained based on their different properties. The kinetic study led to first order rate constants of 10-3 min -1, 6.4*10-3 min -1, 9.2*10-3 min -1, and 4.16*10-2 min- 1 using KPS, H2O2, HC, and HC-KPS-H2O2, respectively. A synergetic coefficient of 2.51 obtained by HC-KPS-H2O2 proved the effectiveness of this combined process. Analysis of cavitation yield efficiency showed an improvement of 98% for the HC-KPS-H2O2 combined process as compared to sole HC treatment process.