Progress in ceramic membrane coupling ozonation process for water and wastewater treatment: A critical review

The combination of membrane filtration and heterogeneous catalytic ozonation (hybrid ozonation membrane filtration (HOMF) process) was receiving increasing attention for water treatment due to its ability to eliminate contaminants and prevent membrane fouling and catalyst loss. Research in HOMF was just at its infant stage and has not yet been summarized. Due to the limited catalytic capacity of pure ceramic membranes, increasing efforts have been devoted to incorporating active catalysts into the ceramic membranes, thereby fabricating dual-functional membranes with both catalytic and anti-fouling properties. Significant improvements in reaction kinetics occurred in HOMF compared to catalytic ozonation, possibly due to nanoconfinement. However, limited evidence existed and debate continued regarding this nanoconfinement. HOMF also showed good performance in mitigating membrane fouling, with the mechanism yet to be studied and summarized. Accordingly, in this paper, the recent development of HOMF was systematically reviewed. The functionalized catalytic ceramic membranes and their active components, critical performance indicators and key challenges were provided. The membrane fouling control and pollutant removal mechanisms in HOMF systems were particularly summarized for the first time, with a key focus on nanoconfinement. Finally, the HOMF process for water treatment was discussed, including engineering applications, conclusions, and perspectives.