High-performance nitrosamine removal for wastewater reuse with supramolecular membranes

Nitrosamines are carcinogenic micropollutants increasingly detected in wastewater effluents and water reuse systems. Conventional reverse osmosis membranes provide limited removal. Here, thin-film nanocomposite membranes incorporating supramolecular 2-hydroxy-N-(diphenylmethyl) acetamide (HNDPA) assemblies were developed for highly selective water transport and rejection of neutral pollutants. The membranes achieved high rejection of low-molecular-weight nitrosamines compared to commercial reverse osmosis membranes, while maintaining high productivity. The neutral solute analysis indicated a sharper molecular cutoff at a Stokes radius of roughly 0.26 nm. Stable flux and rejection were maintained under high-recovery (75%) conditions. Density functional theory and molecular dynamics simulations indicated that HNDPA incorporation promotes a consistent reduction of solute diffusivity and enhanced rejection performance. These results indicate that supramolecular water channel incorporation provides a scalable membrane design strategy to enhance the safety and efficiency of wastewater treatment and high-recovery reuse applications.