MOF and MOF-based membranes: promising solutions for pharmaceutical wastewater treatment

Abstract

Water contamination has become a significant global issue in recent decades, with pollutants, such as heavy metals, acids, organic solvents, and pharmaceutical waste contributing to environmental degradation. Various techniques are employed for treating pharmaceutical wastewater, but metal–organic frameworks (MOFs) are gaining increasing attention due to their unique properties. MOFs offer exceptional porosity, modular structures, high crystallinity, customizable chemical components, large specific surface area, simple functionalization, and numerous active sites. These coordination compounds consist of poly-nuclear metal nodes and organic linkers, forming highly porous structures. This review focuses on MOF-based membrane separation techniques, including membrane filtration (MF), nanofiltration, organic solvent nanofiltration, ultrafiltration (UF), microfiltration, forward osmosis, reverse osmosis, membrane pervaporation, and membrane distillation, along with their mechanisms for removing pharmaceutical waste. MOFs have shown great promise in enhancing membrane performance by improving adsorption capacities, increasing water flow rates, and optimizing membrane properties. Integrating MOFs with materials like graphene oxide, titania, and silica has further improved their performance. Additionally, green synthesis methods are being developed to create eco-friendly MOFs for sustainable wastewater treatment. MOFs demonstrate effective adsorption capacities for various contaminants, including antibiotics, such as tetracycline, nitroimidazole, and quinolone. Functionalizing MOFs with specific groups has been shown to further enhance their adsorption efficiency. Overall, MOFs offer significant potential for advancing pharmaceutical wastewater treatment and addressing global water contamination challenges.