A comprehensive review of forward osmosis and niche applications

Despite intense research effort over the past 15 years, industrial and commercial application of forward osmosis (FO) technology has been slow to become established. Here, the recent improvements in FO technology are critically reviewed, with barriers to full-scale application highlighted. A brief introduction to the FO process is given, with subsequent critical focus on advances in membrane fabrication techniques to minimize fouling and enhance forward flux (e.g. incorporation of fillers, nanostructured surfaces), hybrid processes incorporating combined benefit from concentration-dilution (e.g. fertilizer-based solutions for agricultural irrigation, coupling of gas field produced water-desalination brine processing), and tailoring and improvements in draw solutions (e.g., thermo-responsive polymers, hydrogels, nanoparticles etc.) for targeted applications with minimized reverse solute flux and draw solution regeneration cost. The pilot and full scale industrial applications and areas where FO shows distinct promise over mature technologies are summarized, with emphasis on companies operating in this space as well as the application of life cycle cost analysis to compare and contrast technology application for full economic costing of FO at the commercial scale. The scope for innovation and current impediments to FO technology adoption are comprehensively addressed.