In this study, we aimed to develop a forward osmosis (FO) thin film composite (TFC) membrane which could retain NH₄⁺ from wastewater. The conventional TFC membrane has a microporous polymer support and a selective layer for salt rejection; however, the polyamide selective layer is known to not be able to reject NH₄⁺. Our strategy was to develop tris(2-aminoethyl)amine (TAEA)-modified TFC membranes via secondary interfacial polymerization, and the modification factors were optimized. The NH₄⁺ rejection of the optimized membrane significantly increased from 64.9 % (pristine TFC) to 94.7 %. TAEA modification resulted in a smoother surface and thinner polyamide selective layers. The mechanism of NH₄⁺ rejection during FO operation was investigated and was found to be influenced by membrane surface carboxylic group density and the polyamide crosslinking, cation exchange between the draw and feed solutions, and size sieving. In conclusion, the TAEA-modified membrane showed high selectivity against NH₄⁺ and applicability for NH₄⁺ recovery. In the future, the TAEA-modified membrane may be applied for NH₄⁺ enrichment and recovery from real wastewater systems.

在本研究中，我们旨在开发一种正向渗透 (FO) 薄膜复合 (TFC) 膜，该膜可以截留废水中的 NH ₄ ⁺。传统的 TFC 膜具有微孔聚合物载体和用于脱盐的选择性层；然而，已知聚酰胺选择层不能排斥NH ₄ ⁺。我们的策略是通过二次界面聚合开发三（2-氨基乙基）胺（TAEA）改性的TFC膜，并优化改性因子。优化后的膜的 NH ₄ ⁺截留率从 64.9 %（原始 TFC）显着提高到 94.7 %。TAEA 改性导致更光滑的表面和更薄的聚酰胺选择性层。_{NH 4}的机理⁺对 FO 操作期间的排斥进行了研究，发现受膜表面羧基密度和聚酰胺交联、汲取溶液和进料溶液之间的阳离子交换以及尺寸筛分的影响。总之，TAEA修饰的膜对NH 4 + 表现出高选择性_{和对NH 4} ⁺_回收^的适用性。未来，TAEA 改性膜可用于 NH ₄ ⁺的富集和实际废水系统的回收。