State-of-the-art in forward osmosis membrane process: materials, fabrication, and applications

Abstract

Forward osmosis (FO) is a promising, low-energy membrane process as compared to pressure-driven technologies like reverse osmosis. This review critically discusses the progress in FO membrane technology, taking the advances in materials, preparation methods, and real-world applications into consideration. Recent progress in nanoparticle-doped micro- or nanoporous membranes, bioinspired nanostructured membranes and stimuli-responsive polymers may boost the water permeation, selectivity and anti-fouling capacity. Electrospinning and layer-by-layer assembly, as novel fabrication strategies provide better control of membrane architecture and performance. One more approach can also be found in introducing materials including, but not limited to, graphene oxide, carbon nanotubes and metal-organic frameworks into FO membranes to enhance water flux, salt rejection and membrane mechanical stability. In particular, optimized membranes have achieved water flux up to 83.55 % higher and reverse salt flux up to 75.58 % lower than their simulated counterparts, highlighting their enhanced performance. Moreover, inherent challenges including internal concentration polarization, scalability and membrane long-term stability are outlined, as well as potential strategies for circumventing these drawbacks. They are also discussed for potential applications in industrial desalination, wastewater treatment, food processing, and resource recovery, and their importance in achieving sustainability in the utilization of water.