Design and development of a modified nanobubble-assisted advanced oxidation process (M-AOP) for high-efficiency wastewater treatment

The increasing prevalence of recalcitrant organic pollutants in wastewater necessitates the development of advanced, highly efficient treatment technologies beyond conventional methods, which often struggle with cost-effectiveness and complete pollutant mineralization. This study aimed to design, assemble, and evaluate a novel Modified Advanced Oxidation Process (M-AOP) that integrates a gas nanobubble injection unit with a multi-component oxidative system to overcome the limitations of standard treatments. The performance of the developed M-AOP was rigorously compared against a normal aeration system (T1) and a conventional AOP system (T2) for the removal of chemical oxygen demand (COD) from real municipal wastewater over a 15-hour treatment period. The M-AOP system (T3) demonstrated superior performance, achieving a COD removal rate of 97.9 ± 0.3%, significantly higher than that of the conventional AOP (70.6 ± 2.1%) and normal aeration (36.1 ± 1.5%). The overall COD reduction in the M-AOP system was 2.4 and 1.3 times greater than in T1 and T2, respectively. Furthermore, the M-AOP exhibited a remarkably high initial removal rate of 85.5% within the first 5 h, indicating a rapid and potent oxidative capability. In conclusion, the integration of nanobubble technology significantly enhanced the efficacy of advanced oxidation processes, enabling near-complete COD removal. The M-AOP system represented a promising and robust solution for treating organic-laden wastewater. Future research will focus on pilot-scale validation, a detailed techno-economic analysis, and the system's efficiency in removing specific micropollutants and pathogens.