An update on the use of forward osmosis desalination technology for water treatment: Current trends and future research outlooks

The prevailing water security plights grossly hinged on climate change and population growth, leading to water scarcity, unequal access, and pollution that perpetually exacerbate the ever-increasing crisis and availability of water in the world, continue to call for prudent and pragmatic ways to manage this circular resource (i.e., water). Therefore, the adoption of economical and eco-friendly water treatment technology in response to the need for clean water, along with measures to mitigate energy constraints attached to energy-intensive and hefty water treatment facilities, becomes a panacea. Hence, this state-of-the-art review highlights milestones made to fast-track commercial adoption of forward osmosis (FO) technology for desalinating wastewater, brackish and seawater in a quest to grossly increase clean water availability. Herein, FO membrane technology was distilled as a suitable candidate to offer enormous opportunities for the rapidly expanding and emerging desalination industry, which is presently dominated by reverse osmosis (RO) and thermal technologies. An analysis of FO commercialisation showed that North America (40%), Europe (30%) and Asia-Pacific (25%) are leading regions in the water sector. This also corroborated the market analysis results, which estimated a compound annual growth rate (CAGR) of 10.5% as the market is forecasted to reach 1.774 billion $USD in 2031, showing a substantial increase from 975 million $USD, which was reported for 2025. Moreover, misconceptions and inconsistencies associated with FO were also reviewed in order to update the knowledge base, along with the drawbacks and their respective mitigation strategies. Furthermore, high flux regenerative draw solutes, hybrid renewable energy powered FO systems, minimal liquid discharge (MLD) and/or zero liquid discharge (ZLD) and systems with less concentration polarization (CP), reverse solute diffusion (RSD), and membrane fouling are critical for achieving sustainability and efficiency in FO desalination processes, and this has been meticulously underscored in this much-needed review paper. Future research outlook, critical gaps and avenues of consideration are also elucidated.