A novel thin film nanocomposite (TFN) forward osmosis (FO) membrane with a positively charged and nanofunctional substrate layer has been developed for effective heavy metal ions removal. The substrate layer is constructed by adding titania nanotubes and magnetite oxide hybrid nanoparticles (TNT–Fe₃O₄) in the polysulfone (PSf) matrix. The introduction of nanoparticles endowed the substrate layer with improved hydrophilicity and loose structure. The modified substrate layer also improved the affinity between the nanofillers and polymer matrix, hence maintaining the selectivity of membrane. Compared to pristine thin film composite (TFC) membrane, the TFN with 0.5 wt.% nanofillers loading showed enhanced water flux from 1.63 to 2.82 L m⁻² h⁻¹ without losing its selectivity in terms of J_s/J_v ratio when operated in FO mode. The enhancement was mainly attributed to the improved substrate hydrophilicity which has effectively reduced the internal polarization concentration (ICP). The best performing TFN-0.5 membrane increased the water flux with 73% compared to TFC and exhibited a high Cd²⁺ and Pb²⁺ heavy metal ion rejection of >98%. By designing the substrate layer, this study demonstrated the feasibility of enhancing the performance of FO membrane for treating heavy metal wastewater through a simple and efficient method.

已经开发出具有带正电且纳米功能的基材层的新型薄膜纳米复合材料（TFN）正渗透（FO）膜，可有效去除重金属离子。通过在聚砜（PSf）基质中添加二氧化钛纳米管和氧化磁铁矿杂化纳米颗粒（TNT–Fe ₃ O ₄）来构造基底层。纳米颗粒的引入使基底层具有改善的亲水性和疏松结构。改性的基底层还改善了纳米填料与聚合物基质之间的亲和力，因此维持了膜的选择性。与原始薄膜复合（TFC）膜相比，具有0.5 wt。％纳米填料负载的TFN的水通量从1.63升至2.82 L m ^-2  h ^-1在FO模式下操作时，在J _s / J _v比方面不会损失其选择性。增强主要归因于改善的基材亲水性，该亲水性有效降低了内部极化浓度（ICP）。与TFC相比，性能最好的TFN-0.5膜将水通量提高了73％，并表现出> 98％的高Cd ²⁺和Pb ²⁺重金属离子排斥率。通过设计基底层，本研究证明了通过简单有效的方法提高FO膜处理重金属废水性能的可行性。