This study used a novel nitrogen-doped biochar (N-C) to catalyze the oxidative degradation of IBP in water by ozone and studied the catalytic ozone oxidation degradation of ibuprofen (IBP) efficiency and mechanism. Furthermore, it explored the influence of pH, ozone dosing quantity, catalyst dosing quantity, different anions, and background of water quality conditions on the IBP degradation efficiency. The results showed that, compared with that of some common carbon-based catalysts (g-C3N4, biochar, and granular-activated carbon) and metal catalysts (MnO2 and Fe3O4), the N-C catalytic ozone system had a very outstanding oxidation degradation performance of organic pollutants; the removal rate of IBP reached 100% in 5 min, and the utilization rate of ozone was increased from 10% to 46%. The treatment efficiency of the system was enhanced with the increase in pH. Compared with that by increasing the ozone dosage, the treatment capacity of the system was significantly improved by increasing the concentration of catalyst. The quenching experiment and EPR further confirmed that N-C could effectively catalyze ozone to produce more reactive oxygen species, such as superoxide radicals (·O2-) and H2O2. It was also found that·O2- was the main active substance in the reaction system and played a leading role in the degradation of IBP.
Keywords: catalytic ozone; ibuprofen (IBP); nitrogen-doped biochar; ozone oxidation; superoxide radical(·O-2).