Hydraulic-Driven Piezo-Activation of Peroxymonosulfate for Carbamazepine Degradation with Ultralow Energy Consumption

Although peroxymonosulfate (PMS) coupling with ultrasonic piezo-catalysis (PE) or electrolysis (E) exhibited synergy of organics degradation by generating more reactive oxidative species (ROS), the relatively high energy consumption restricted their application. Hydro-energy, as a clean energy resource, is available in water treatment and transportation processes. Herein, a hydraulic-driven PE-PMS process was proposed, using barium titanate (BaTiO3, BT) as piezoelectric material for carbamazepine (CBZ) degradation. Notably, CBZ was efficiently degraded in the hydraulic PE-PMS process with a pseudo-first-order rate constant of 8.15 × 10−3 min−1, and the synergy index was as high as 14.90. The BT maintained satisfactory performance without valence and crystal phase changes after 10 cycles. Importantly, the energy consumption of hydraulic PE-PMS process was only 2.56% and 22.87% of ultrasonic PE-PMS and traditional E-PMS processes, respectively. Besides, finite element method and electrochemical measurement were performed to understand the influence of the hydraulic gradient (G). A positive correlation between G and piezo-potential/current was found in the hydraulic PE-PMS process. However, there was an optimal G value (7.72 s−1 ) for CBZ degradation. Further studies showed that •OH played a major role in CBZ degradation during the hydraulic PE-PMS process. Moreover, various refractory organics could be effectively degraded in this process, while a satisfactory degradation of CBZ was observed in the actual water matrices. Therefore, the hydraulic-driven PE-PMS system might be an efficient, sustainable, and energy-saving process for water treatment by the potential utilization of residual hydro-energy in water transportation