Lu Xiaozhen, Wang Lin, Peng Hong, Zhu Xuewu, Yang Zhe, Wei Jiashuai, Liu Bin
Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha 410082, PR China.
School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, PR China.
Environ Sci Technol. 2025 Sep 16;59(36):19593-19603. doi: 10.1021/acs.est.5c07291. Epub 2025 Sep 4.
Polyamide (PA) nanofiltration (NF) membranes represent a promising approach to safe drinking water production. Yet, selective removal of contaminants while retaining essential minerals remains a critical challenge for cost-effective water treatment processes. Here, we employed ammonia bicarbonate (AB) as an economical additive to modify interfacial polymerization (IP) for developing high-performance NF membranes suitable for drinking water applications. Comprehensive characterization coupled with molecular dynamics simulations demonstrate that AB modulates the IP process through three mechanisms: (1) controlling the diffusion kinetics of piperazine (PIP) at the aqueous-organic interface, (2) the reaction between HCO and H produced by IP achieves nanofoaming, and (3) the thermal decomposition of AB releases additional gaseous products (NH and CO), enhancing the dual nanofoaming effect. This controlled reaction kinetics and increased nanobubble formation produced a thinner, more wrinkled PA selective layer with an optimized microstructure. The optimized NF-AB-8 membrane demonstrated enhanced permeance (28.5 LMH/bar) during actual surface water purification, while maintaining selective separation between minerals and dissolved organic matter ( = 34.5). In addition, the improved microstructure and separation performance enhanced the antiscaling and antifouling properties of the NF membrane. This study explored the application of dual-nanofoaming mechanisms in NF membranes, providing insights for designing NF membranes that simultaneously improve permeance and selectivity, which may promote the preparation of high-performance NF membranes and their application in drinking water production.
聚酰胺（PA）纳滤（NF）膜是一种生产安全饮用水的很有前景的方法。然而，在保留必需矿物质的同时选择性去除污染物，对于经济高效的水处理工艺来说仍然是一项严峻挑战。在此，我们采用碳酸氢铵（AB）作为一种经济的添加剂来改性界面聚合（IP），以开发适用于饮用水应用的高性能NF膜。综合表征与分子动力学模拟表明，AB通过三种机制调节IP过程：（1）控制哌嗪（PIP）在水-有机界面处的扩散动力学；（2）IP产生的HCO与H之间的反应实现纳米发泡；（3）AB的热分解释放额外的气态产物（NH和CO），增强双重纳米发泡效果。这种可控的反应动力学和增加的纳米气泡形成产生了一个更薄、更褶皱的具有优化微观结构的PA选择性层。优化后的NF-AB-8膜在实际地表水净化过程中表现出增强的通量（28.5 LMH/bar），同时保持了矿物质与溶解有机物之间的选择性分离（= 34.5）。此外，改进的微观结构和分离性能增强了NF膜的抗结垢和抗污染性能。本研究探索了双重纳米发泡机制在NF膜中的应用，为设计同时提高通量和选择性的NF膜提供了见解，这可能会促进高性能NF膜的制备及其在饮用水生产中的应用。
