One-pot fabrication of highly permeable P84/UiO-66-NH2-PEI membrane for the efficient removal of heavy metals from wastewater

Heavy metal pollution threatens water bodies and public health, necessitating the exploration of advanced technologies to effectively remove heavy metals from wastewater. In this study, a one-pot approach was employed to fabricate a positively charged membrane using P84 as the substrate, and UiO-66-NH2 nanoparticles and PEI as crosslinkers. Introducing UiO-66-NH2 with inherent porous structures can create nanopores and gaps within the PA layer, providing extra pathways for water molecules to permeate the membrane. Moreover, the UiO-66-NH2 nanoparticles imparted hydrophilicity and a positive charge to the resulting membrane. Compared to the blank membrane without UiO-66-NH2 nanoparticles, the optimal membrane demonstrated a significant increase of 44 % in water flux (52.4 L m- 2h- 1) while maintaining a remarkable removal performance for CuCl2 (99.5 %), PbCl2 (99.4 %), Ni(NO3)2 (98.6 %), and ZnCl2 (98.4 %) at 4 bar. Furthermore, the UiO-66-NH2 nanoparticles can cross-link with the P84 polymer, ensuring a stable attachment between the polyamide (PA) layer and the P84 substrate by covalent bonds, preventing the potential conventional nanoparticle leakage. Additionally, three different fabrication methods were employed to explore the optimal approach for incorporating UiO-66-NH2 nanoparticles, with each method resulting in a distinct distribution of nanoparticles within the membrane. This study highlights the potential of the resultant membranes in addressing the challenges of wastewater treatment, offering a facile and promising avenue for heavy metal removal.