摘要
Nanofiltration (NF) has significant potential for water reclamation, but it encounters several critical challenges, including unsatisfactory removals of dissolved small-molecular contaminants such as antibiotics, an inherent permeability-selectivity trade-off, and severe membrane fouling. Herein, we present a groundbreaking advancement in addressing these issues through an electric field-assisted filtration with a conductive NF membrane fabricated by interfacial polymerization of polyamide on a carbon nanotube substrate (pCNT-PA). The effects of electric field strength, solution pH, ionic strength, and combined organic-inorganic foulants on the removal efficiencies of various antibiotics of the conductive NF membrane under electric field-assisted filtration were investigated. The results show that, when the conductive membrane was used as a cathode under an applied voltage of 1.5 V, the rejection rates of sulfamethoxazole and ibuprofen substantially increased from 79.3 % and 59.3 % to 99.5 % and 90.8 %, respectively. This improvement is primarily attributed to the electric field induced increase in membrane charge density, rather than the alteration of membrane pore size. The elevated charge density enhances the electrostatic repulsion between anionic antibiotics and negatively polarized membrane. Based on this mechanism, the pCNT-PA membrane presented voltage-gated separation towards binary and ternary antibiotics with distinct charge characteristics. Furthermore, the electric field-assisted NF process exhibited remarkable antifouling performance, maintaining over 95 % sulfamethoxazole removal efficiency in the presence of combined organic-inorganic foulants. This work advances the understanding of electric field-regulated antibiotic removal mechanisms in NF systems, providing new theoretical insights for the development of intelligent responsive membrane separation technologies.
危险品化学品经营许可证（带存储）