Applications of metal-organic framework based membranes in water purification: A review

Metal-organic frameworks (MOFs) have attracted a great deal of attention due to their flexibility and various potential applications. MOF-based membranes have been widely applied in forward-osmosis (FO), reverse-osmosis (RO), nanofiltration (NF), and ultrafiltration (UF) processes. While a few recent studies have reviewed the applications of MOF-based membranes in water purification, a systematic understanding is still necessary to evaluate the transport mechanisms of various compounds by different MOF-based membranes under various operating and water-quality conditions. Here, we present a comprehensive literature review of recent findings and suggest future research trends by identifying insufficiencies of current knowledge, focusing on the performance of MOF-based membranes in water purification, as the transport of inorganic and organic compounds by MOF-based membranes is highly influenced by the different properties of compounds in addition to water-chemistry conditions and membrane properties. This study focused on several main parameters such as methods for synthesis of MOF-based membranes, membrane properties, and the physicochemical properties of various compounds, which affect the transport of compounds during MOF-based FO/RO/NF/UF membrane filtration. In addition, we provide the continuing challenges and areas of future study in this field.