Heavy metals (HMs) are highly toxic water pollutants abundant in industrial wastewater. Herein, a bis[3-(trimethoxysilyl)propyl]amine (BTMSPA) cross-linked multiwalled carbon nanotube (MWCNT) nanomaterial (CQACNT) was synthesized by silanization of MWCNT-OH followed by grafting of positively charged quaternary ammonium groups (glycidyl trimethyl ammonium chloride (GTMAC)) by an epoxide ring-opening reaction. The composite membranes were prepared by the incorporation of CQACNT into the poly(ether sulfone) (PES) polymer matrix. The CQACNT-6 composite membrane exhibited a 3.5-fold increase in pure water permeability (PWP; 312.8 L m⁻² h⁻¹ bar⁻¹) as compared to the pristine PES (CQACNT-0) membrane (89.6 L m⁻² h⁻¹ bar⁻¹). Moreover, the CQACNT-6 composite membrane showed high HM removal rates (Pb: 89.53%; Ni: 90.42%; Cu: 91.43%; Zn: 91.86%) as compared to the CQACNT-0 membrane (Pb: 39.73%; Ni: 40.32%; Cu: 42.52%; and Zn: 43.91%). After 9 treatment cycles, the CQACNT-6 membrane retained up to 87%, and 94% of its initial PWP and initial Cu²⁺ rejection, respectively, compared to only 58%, and 54%, respectively for pristine CQACNT-0. The positively charged quaternary ammonium groups enhanced the surface features of PES and MWCNTS, resulting in competitive HM removal rates due to the electrostatic repulsion between the HM and the porous membranes, as well as high PWP.

重金属（HMs）是工业废水中大量存在的剧毒水污染物。在此，通过将 MWCNT-OH 硅烷化，然后接枝带正电荷的季铵基团（缩水甘油基三甲基铵氯化物（GTMAC））通过环氧化物开环反应。通过将 CQACNT 掺入聚（醚砜）（PES）聚合物基质中制备复合膜。^{与原始 PES (CQACNT-0) 膜 (89.6 L m -2}  h ) 相比，CQACNT-6 复合膜的纯水渗透率 (PWP; 312.8 L m ^-2  h ^-1  bar ^{-1 ) 增加了 3.5 倍-1} 条^-1 )。此外，与 CQACNT-0 膜（Pb：39.73%；Ni： 40.32%；Cu：42.52%；和 Zn：43.91%)。在 9 个处理周期后，CQACNT-6 膜分别保留了高达 87% 和 94% 的初始 PWP 和初始 Cu ²⁺排斥，而原始 CQACNT-0 分别仅为 58% 和 54%。带正电荷的季铵基团增强了 PES 和 MWCNTS 的表面特征，由于 HM 和多孔膜之间的静电排斥以及高 PWP，导致具有竞争力的 HM 去除率。