Enhanced Hydraulic-driven piezoelectric ozonation performance by CNTs/BaTiO3 nanocatalyst for Ibuprofen removal

The performance of hydraulic-driven piezoelectric catalysis process is not satisfactory for refractory organics degradation. Although the ozonation process catalyzed by carbon nanotubes (CNTs) can increase the removal of refractory organics, the CNTs can be destroyed by ozone to reduce catalytic activity. Hence, a carbon nanotubes/BaTiO3 (CNTs/BT) composite was prepared and employed to catalyze ozone for ibuprofen (IBP) removal under hydraulic force. The removal rate of IBP in the CNTs/BT-O3 process was significantly higher than that in CNTs-O3 and BT-O3 processes. This outstanding performance was attributed to the adsorption and surface diffusion of CNTs, efficient electron transfer, as well as strong piezo-potential for abundant active species generation (such as OH and O2−). Notably, the removal of IBP only decreased by 3.19 % after 5 cycles of CNTs/BT composite with no metal ions leakage. In terms of energy consumption, the CNTs/BT-O3 process is not only superior to traditional ozone-based advanced oxidation processes (such as US-O3, UV-O3, and E-O3), but also outperforms the recently proposed piezoelectric ozonation process. Moreover, various refractory pollutants were effectively removed in CNTs/BT-O3 process, and satisfactory removal of IBP was observed in the actual water matrix. This study provides an effective and stable approach to removing refractory organics.