Elimination of PPCPs using ozonation-assisted electrochemical filtration with a Ti3C2Tx/CNTs membrane electrode: Performance, mechanisms, and application potential

Pharmaceuticals and personal care products (PPCPs) pose potential risks to aquatic ecosystems and human health. This work developed an ozonation-assisted electrochemical filtration (OAEF) system using a Ti 3 C 2 T x /CNTs composite membrane electrode and systematically investigated its efficiency, mechanisms, and practicality for PPCPs removal. The results suggest that the excellent adsorption and hydrophilic properties of Ti 3 C 2 T x , combined with its formation of an optimized membrane structure when mixed with CNTs, significantly enhanced the pollutant adsorption capacity and water permeation flux of fabricated electrode. Ozone incorporation in the electrochemical filtration process facilitated pollutant abatement, achieving approximately 99 % degradation and 42 % mineralization of fluoxetine (FLX), a representative PPCP. Moreover, the OAEF system demonstrated broad pH suitability and good stability, effectively detoxifying FLX-contaminated wastewater. The analysis of oxidants and electrode component evolution in the OAEF system, combined with density functional theory (DFT) calculations, revealed that enhanced mass transfer and electron transport promoted electro-peroxone initiation and reactive oxygen species (ROS) generation, thereby improving pollutant elimination and regenerating the adsorption capacity of electrode. Further analysis of 34 PPCPs treatment using quantitative structure-activity relationship (QSAR) models indicated that adsorption on the Ti 3 C 2 T x /CNTs was primarily influenced by pollutant solubility, C O bond content, dipole moment, and molecular weight, while degradation was significantly impacted by aromatic ring content, highest occupied molecular orbital (HOMO) energy, lowest unoccupied molecular orbital (LUMO) energy, and solubility. Additionally, the Ti 3 C 2 T x /CNTs membrane electrode exhibited satisfied fouling mitigation during the treatment of real surface water, suggesting that the OAEF process is feasible for practical applications.