The effect of interlayer water of metal-modified montmorillonite for catalytic ozonation

The catalytic ozonation-based advanced oxidation process (AOP) is applied to remove nondegradable chemical oxygen demand (COD), while the application in industry is limited by the economics and activity of catalysts. In this study, we demonstrate that by taking atrazine (ATZ) as a model pollutant, the removal rates of catalytic ozonation were negatively correlated with the interlayer water content of metal-modified montmorillonite (Mx@MMT), instead of the loadings metals. Among the modified MMT, Zn0.1@MMT achieved 83.2% degrada-tion of ATZ within 15 min, and corresponding removal rates of COD and total organic carbon (TOC) reached 40.3% and 46.5%, respectively. Detailed EPR and quenching experiments identified that hydroxyl radicals (HO center dot) were the main reactive oxygen species and QTOF/MS/MS analysis helped to propose a possible degradation pathway of ATZ. Moreover, the catalytic performance of Zn0.1@MMT under different conditions was also sys-tematically evaluated.