A Critical Review on the Progress, Challenges, and Future Outlook of Forward Osmosis Desalination in the 21st Century

The escalating global water crisis, driven by population growth, climate change, and increasing industrial demands, has positioned water scarcity as one of the most pressing challenges of the 21^st century. With freshwater resources becoming increasingly limited and unevenly distributed, desalination technologies have emerged as critical solutions to meet growing water demands. Among various desalination approaches, forward osmosis (FO) has garnered significant attention as a promising low fouling technology that offers distinct advantages over conventional methods. This critical review provides a comprehensive analysis of FO's evolution, challenges, mechanisms, and prospects. It offers an in-depth examination of some significant literature reviews since 2019 to identify current research gaps in FO desalination and advance the field. The review evaluates draw agents and membrane properties, investigates FO's energy efficiency compared with other techniques, and environmental impacts. A three-phase roadmap is proposed involving collaborative integration of key stakeholders, scaling up for remote applications, and development of autonomous artificial intelligence networks for adaptive treatment responses.