p-Nitrophenol Removal by Bauxite Ore Assisted Ozonation and its Catalytic Potential

The catalytic ozonation process (COP) has attracted wide attention in the treatment of recalcitrant organic contaminants because of its high efficiency and easy operation. In this study, the bauxite ore (BO) was used as a heterogeneous catalyst to catalyze ozonation of p‐nitrophenol in water. Calcined BO (CBO) assisted COP (CBO–COP) exhibited a higher degradation and mineralization performance for p‐nitrophenol in comparison with raw BO assisted COP and single ozonation process (SOP). The CBO–COP was dominated by hydroxyl radical mediated oxidation on the CBO surface, following a pseudo‐first order kinetics with a reaction rate constant of 0.1944 min−1 at 298.15 K and an activation energy of 6.476 kJ mol−1. The reaction rate constants increased by about 76% at 298.15 K and 45% at 308.15 K and activation energy decreased by approximately 70% in CBO–COP compared to those in SOP. p‐Nitrophenol in CBO–COP was first transformed into 4‐nitrocatechol, pyrocatechol, hydroquinone, phenol p‐benzoquinone, and o‐benzoquinone, and then into benzoquinone, maleic acid, fumaric acid, acetic anhydride, acetic acid, formic acid, or directly mineralized to carbon dioxide and water. The results demonstrated the catalytic potential of BO for ozonation of recalcitrant organic contaminants considering low cost and earth‐abundant reserves. The catalytic ozonation process has attracted wide attention in the recalcitrant contaminants treatment. Calcined bauxite ore exhibited higher degradation and mineralization performance in the catalytic ozonation of p‐nitrophenol than a single ozonation process. The results demonstrated the catalytic potential of bauxite ore for the ozonation of recalcitrant organic contaminants considering low cost and abundant reserves.