Recent Advances in High-Gravity Ozonation for Wastewater Treatment

Ozonation is widely used in wastewater treatment, but its efficiency is often limited by the low solubility of ozone and insufficient gas–liquid mass transfer. High-gravity technology offers an effective intensification strategy by enhancing liquid-film renewal, interfacial contact, and micromixing under centrifugal fields. This review summarizes recent advances in high-gravity ozonation for wastewater treatment. The fundamental oxidation pathways of ozonation, the characteristics of typical high-gravity reactors, and recent applications in both homogeneous and heterogeneous systems are discussed. Current studies show that high-gravity ozonation can significantly improve ozone utilization, pollutant degradation, and mineralization efficiency. It was reported that the equilibrium dissolved ozone concentration and ozone decomposition rate constant in heterogeneous catalytic high-gravity systems were 2.5 and 2.6 times higher than those in conventional bubbling reactors, respectively, leading to markedly enhanced pollutant and TOC removal. These findings highlight the potential of high-gravity ozonation for intensified wastewater treatment. Despite these advances, its practical application still faces challenges related to real wastewater adaptability, byproduct and toxicity control, reactor scale-up, catalyst stability, economic feasibility, and energy demand. This review provides a useful reference for the further development and engineering application of high-gravity ozonation technology.