Enhancing Advanced Oxidation Process by Microbubbles Technology and the Analysis of Its Degradation Process

The simulated dyestuff containing Indigo Carmine(IC), a highly toxic indigoid dye used as a textile coloring agent, was studied using hydrogen peroxide as oxidant enhanced by microbubbles. The decolorization rate, chemical oxygen demand (COD) and total organic carbon (TOC) removal extent were dramatically increased by the presence of microbubbles. The discoloration was observed in this system up to 94.27%, compared with about 49.6% without hydrogen peroxide in 60 minutes, and COD and TOC removal rate can achieve to 72% and 53.07%, respectively. In addition, the main degradation pathway was analyzed by Fluorescence (FLS), Ultraviolet Visible (UV-Vis) and Ultra High Liquid Chromatography and Time of Flight Mass Spectrometry (UPLC-Q-TOF-MS). The results showed that hydroxyl radicals (center dot OH) induced strong oxidizing effects in the target solution and destroyed the chromophoric groups of the molecular structure. The application of microbubbles technology in the advanced oxidization process may provide an effective and low-cost approach for treating dye wastewater.