State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji Advanced Membrane Technology Center, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Environ Sci Technol. 2024 May 28;58(21):9416-9426. doi: 10.1021/acs.est.4c01383. Epub 2024 Apr 25.
The polyamide (PA) nanofiltration (NF) membrane has the potential to remove endocrine-disrupting compounds (EDCs) from water and wastewater to prevent risks to both the aquatic ecosystem and human health. However, our understanding of the EDC removal-water permeance trade-off by the PA NF membrane is still limited, although the salt selectivity-water permeance trade-off has been well illustrated. This constrains the precise design of a high-performance membrane for removing EDCs. In this study, we manipulated the PA nanostructures of NF membranes by altering piperazine (PIP) monomer concentrations during the interfacial polymerization (IP) process. The upper bound coefficient for EDC selectivity-water permeance was demonstrated to be more than two magnitudes lower than that for salt selectivity-water permeance. Such variations were derived from the different membrane-solute interactions, in which the water/EDC selectivity was determined by the combined effects of steric exclusion and the hydrophobic interaction, while the electrostatic interaction and steric exclusion played crucial roles in water/salt selectivity. We further highlighted the role of the pore number and residual groups during the transport of EDC molecules across the PA membrane via molecular dynamics (MD) simulations. Fewer pores decreased the transport channels, and the existence of residual groups might cause steric hindrance and dynamic disturbance to EDC transport inside the membrane. This study elucidated the trade-off phenomenon and mechanisms between EDC selectivity and water permeance, providing a theoretical reference for the precise design of PA NF membranes for effective removal of EDCs in water reuse.
聚酰胺（PA）纳滤（NF）膜具有从水中去除内分泌干扰化合物（EDCs）的潜力，以防止对水生生态系统和人类健康造成风险。然而，尽管已经很好地说明了盐选择性-水渗透性的权衡关系，但我们对 PA NF 膜去除 EDC-水渗透性权衡的理解仍然有限。这限制了用于去除 EDC 的高性能膜的精确设计。在这项研究中，我们通过在界面聚合（IP）过程中改变哌嗪（PIP）单体浓度来操纵 NF 膜的 PA 纳米结构。EDC 选择性-水渗透性的上限系数被证明比盐选择性-水渗透性的上限系数低两个数量级以上。这种变化源于不同的膜-溶质相互作用，其中水/EDC 选择性由空间排斥和疏水相互作用的综合影响决定，而静电相互作用和空间排斥在水/盐选择性中起着至关重要的作用。我们还通过分子动力学（MD）模拟进一步强调了在 EDC 分子跨 PA 膜传输过程中孔数和残留基团的作用。较少的孔减少了传输通道，而残留基团的存在可能会对 EDC 在膜内的传输造成空间阻碍和动态干扰。本研究阐明了 EDC 选择性和水渗透性之间的权衡现象和机制，为精确设计用于有效去除水中 EDC 的 PA NF 膜提供了理论参考。
