Progress of researches on synergetic mechanism of micro–nano-bubble-assisted ozonation

Ozonation has become a well-established process in the field of water treatment, especially in disinfection and organic pollutant removal. However, the practical application of this technology is often limited by low mass transfer efficiency, high reaction selectivity, and by-product generation. The introduction of micro-nano bubbles provides an innovative solution to these limitations - its large specific surface area, excellent gas-liquid mass transfer, and long-lasting aqueous phase stability can significantly enhance ozone dissolution efficiency and promote the generation of reactive oxygen species. Recent studies have shown that this micro-nano bubbles synergistic ozone oxidation system exhibits excellent performance in complex water treatment scenarios such as pharmaceutical wastewater treatment and membrane bioreactor maintenance. This paper systematically discusses the synergistic mechanism of ozone and micro-nano bubbles, focusing on the four dimensions of bubbles generation technology, system characterization method, reaction mechanism research, and current technological bottlenecks, which not only provides a theoretical basis for the relevant basic research, but also promotes the large-scale application of this composite technology in the field of water treatment and points to the key scientific issues that need to be broken through.