Hydroxylated UiO-66/Polyvinyl Alcohol Thin-Film Nanocomposite Membranes with High Permeance and Antifouling Performance for Micropollutant Removal.

Abstract

The release of emerging organic contaminants (EOCs), including pharmaceutical active compounds (PhACs), into aquatic systems poses a growing threat to both human health and environmental sustainability. Nanofiltration (NF) membranes offer a promising solution for removing such pollutants; however, challenges such as low selectivity and high fouling tendency during pharmaceutical separation continue to limit their application. In this study, we report eco-friendly, hydroxylated metal-organic framework (UiO-66-OH)-incorporated, glutaraldehyde-crosslinked polyvinyl alcohol-based thin-film nanocomposite membranes (UiO-66-OH@PVA TFN) with enhanced separation performance. Using the strong crosslinking ability of glutaraldehyde and the hydrogen-bonding capability of UiO-66-OH, the resulting membranes exhibit excellent selectivity and resistance to fouling. Incorporating UiO-66-OH into the PVA active layer resulted in a >28% increase in water flux relative to the pristine PVA thin-film composite (TFC) membrane. Zeta potential analysis revealed a more negatively charged membrane surface following UiO-66-OH incorporation, which contributed to the improved rejection of negatively charged PhACs. The molecular weight cut-off (MWCO) of the UiO-66-OH@PVA TFN membrane was approximately 333 Da. Under optimized conditions, the membrane achieved rejection rates of 98.99 ± 0.3, 94.264 ± 0.19, and 79.89 ± 0.17% for ofloxacin (OFL), omeprazole (OMZ), and ibuprofen (IBP), respectively. The membrane demonstrated stable rejection performance (∼98%) over 72 h with minimal flux decline. The membrane showed excellent antifouling performance, with FRRs of 99% (BSA) and 98% (HA). Furthermore, the uniform dispersion of UiO-66-OH within the PVA matrix enhanced the membrane's chlorine resistance. These findings highlight the potential of non-polyamide, hydroxylated MOF-based TFN membranes as a high-performance platform for removing EOCs and PhACs from water.