High-performance thin film composite forward osmosis membrane for efficient rejection of antimony and phenol from wastewater: Characterization, performance, and MD-DFT simulation

Abstract

The effective removal of heavy metals and phenolic pollutants from aqueous solutions has received widespread attention in the field of wastewater treatment. In this work, a novel PAN/CNTs/UiO-66-NH₂ modified forward osmosis (FO) membrane was prepared for efficient removal of antimony (Sb) and phenol from wastewater. The membrane was synthesized using a facile and cost-effective method. The PAN/CNTs substrate membrane was prepared using electrospinning technology, and UiO-66-NH₂ MOF particles were loaded onto the surface of the active layer during the interfacial polymerization (IP) process. The presence of CNTs in the spinning solution regulated the pore structure and properties of nanofibers. Characterization of the membrane confirmed its unique structure and enhanced properties. When the CNTs addition was 0.01 g, and UiO-66-NH₂ addition was 0.05 wt%, the FO membrane exhibited the optimal operational performance. In the AL-FS mode, the water flux, reverse salt flux (RSF), and J_s/J_w ratio were 14.68 LMH, 0.17 gMH, and 0.01 g/L, respectively. As a comparison, the water flux, RSF, and J_s/J_w ratio were 21.19 LMH, 0.65 gMH, and 0.032 g/L in the AL-DS mode, respectively. Simultaneously, efficient removal of antimony and phenol was achieved in both modes, with antimony removal efficiencies of 99.26 % and 97.98 %, and phenol removal efficiencies of 96.61 % and 93.18 %, respectively. The modified membrane exhibited excellent performance in rejecting Sb and phenol. Molecular dynamics simulations and density functional theory calculations provide theoretical support for the excellent performance of membranes. The membrane demonstrated a high water flux, making it promising for practical applications. Additionally, it exhibited remarkably low reverse salt flux, highlighting its suitability for desalination processes. The exceptional removal efficiency of Sb and phenol, coupled with the membrane's impressive hydraulic performance, makes it a promising candidate for the treatment of industrial effluents containing these challenging contaminants. The results presented in this study underscore the potential of PAN/CNTs/UiO-66-NH₂ FO membranes as an advanced solution for addressing water pollution challenges.