Progress on ozone mass transfer enhancement mechanisms in membrane contactor reactors and their applications in textile dyeing and finishing wastewater treatment

Ozonation is an effective advanced treatment technology for textile dyeing and finishing wastewater； however， its large-scale application is primarily constrained by its intrinsically low ozone mass transfer efficiency. Membrane contactor reactors （MCRs） can significantly enhance ozone mass transfer by constructing microscale gas-liquid interfaces， offering advantages such as high mass transfer efficiency and the absence of secondary pollution. Nevertheless， issues including membrane fouling， high material costs， and poor operational stability still limit their engineering-scale implementation. This study systematically reviewed recent advances in the mechanisms of ozone mass transfer enhancement in MCRs. The principles of gas-liquid interfacial mass transfer and the design characteristics of hollow fiber membrane contactor configurations were introduced. The regulatory effects of membrane material properties （e.g.， the selection of hydrophobic PTFE/PVDF）， operating parameters （gas-liquid flow rates， transmembrane pressure， and pH）， and mass transfer models on the volumetric ozone mass transfer coefficient were critically analyzed. Furthermore， the application efficiency of MCRs in textile dyeing and finishing wastewater treatment was evaluated， with particular emphasis on efficient dye removal， organic matter mineralization， and decolorization. Research demonstrated that optimized MCR systems could increase the volumetric ozone mass transfer coefficient by 5~10 times compared with conventional bubble column processes， thereby substantially enhancing the kinetics of pollutant degradation. However， challenges such as membrane fouling-induced flux decline， bromate by-product formation， and cost-benefit optimization remained to be addressed. Finally， future research directions were proposed， focusing on the rational design of multifunctional composite membranes integrating antifouling properties， corrosion resistance， and low cost； the elucidation of interfacial reaction mechanisms through coupling with intensified fields such as high-gravity and electrocatalytic processes； the development of intelligent parameter regulation systems based on process modeling； and comprehensive techno-economic and environmental risk assessments at the pilot scale. These efforts will provide theoretical support and technical guidance for the engineering application of MCR-ozone processes.