Superior performance of catalytic ozonation on molecular-level transformation of effluent organic matter and self-cleaning property in catalytic ozonation membrane reactor

Catalytic ozonation membrane reactor (COMR) is one of the most promising technologies for municipal wastewater reclamation. Herein, we evaluated superior performance of catalytic ozonation in COMR through filtration of effluent organic matter (EfOM) using the origin and three catalytic membranes. We found that filtration primarily contributed to rejection of protein-like fluorescence enriched in relatively high-oxygen compounds (O/C >0.4) with high molecular weight and catalytic ozonation further removed humic-like materials and highly unsaturated, aromatic and reduced compounds (O/C<0.4; H/C<1.3), demonstrating complementary function of catalytic ozonation and filtration. The superior performance of catalytic ozonation than ozonation is reflected in higher removal of medium molecular weighted humic-like materials and S-containing compounds, enhancing the mineralization and reaction extent of EfOM. Additionally, catalytic ozonation exhibited strong self-cleaning property and eliminated irreversible membrane fouling. Our findings provide molecular-level insights into the reaction mechanism governing the COMR towards municipal wastewater reclamation.