Blocking the formation of bromate in γ-Fe-Ti-AlO catalytic ozonation of ibuprofen in bromide-containing water.

Iron and titanium doped γ-AlO (γ-Fe-Ti-AlO) mesoporous catalysts were synthesized by evaporation-induced self-assembly using glucose as template, and applied to ozonation of ibuprofen in bromide-containing water. X-ray diffraction (XRD), nitrogen adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS) results showed that iron and titanium successfully doped into the skeleton of γ-AlO, uniform distribution, maintain the ordered mesoporous structure of γ-AlO, with larger specific surface area. The valence of titanium coexists with Ti and Ti, and the valence of iron was Fe. Infrared spectra of chemisorbed pyridine (Py-FTIR) results showed that the doped titanium and iron into the framework position of γ-AlO altered the surface acidity of the alumina surface, especially increasing the medium Lewis acid sites, which was conducive to the effective decomposition of ozone into active oxygen species. The γ-Fe-Ti-AlO catalyst (Al/Fe = 25, Al/Ti = 75) enhanced the removal rate of ibuprofen in ozonation of bromide-containing water, and effectively blocked the formation of bromate. After the reaction of 60 min, the removal rate of TOC was increased from 54% of γ-AlO/O to 86% with γ-Fe-Ti-AlO/O, while the ozonation alone was only 13%. Electron Paramagnetic Resonance (EPR) spectra showed that hydroxyl and superoxide radicals were reactive oxygen species, which was beneficial to the mineralization of organic matter. The capture experiment of Fe ion confirmed that the electronic cycle of Fe ion and Fe ion was beneficial to block the formation of bromated. The addition of ibuprofen and humic acid can enhance the reduction of Fe in the catalytic ozonation of γ-Fe-Ti-AlO, which further strengthened the blocking of bromate formation.