Interface-Facilitated Removal of Environmental Micropollutants by Nanofiltration Membranes Prepared from Amino Acid-Mediated Interfacial Polymerization: Mechanistic Insights into Micropollutant Interfacial Partitioning Regulation

Environmental organic micropollutants in aquatic systems pose a threat to human health. Conventional nanofiltration membranes struggle with micropollutant removal due to inadequate steric hindrance and unfavorable interactions. This study focused on regulating micropollutant interfacial partitioning by constructing an enhanced separation interface for nanofiltration membranes. Three types of amino acids were introduced into interfacial polymerization to fabricate the amino acid-modified nanofiltration membranes. Molecular dynamics (MD) simulations and density functional theory (DFT) calculations revealed how amino acids regulate monomer diffusion and enable in situ chemical modification. Membrane performance evaluations showed an improved micropollutant removal by the modified membranes. Notably, the rejection of the modified membrane for neutral and positively charged micropollutants can reach up to twice that of the control membrane. The micropollutant interfacial partitioning behavior was elucidated through quartz crystal microbalance with dissipation (QCM-D) measurements and calculation analysis, demonstrating the effectiveness of interface-facilitated micropollutant removal. Additionally, the modified membrane also exhibited enhanced antifouling properties, mitigating the negative impact of the fouling layer on the micropollutant rejection. This study advances our understanding of the regulatory mechanisms governing micropollutant interfacial partitioning on nanofiltration membranes and proposes a simple yet effective strategy for removing organic micropollutants in environmental water treatment.