Recent Advances in the Fabrication of High-Performance Forward Osmosis Membranes to Concentrate Ammonium in Wastewater

Nutrients (phosphorus and nitrogen) removal/recovery from wastewater is important due to economic and environmental issues. To utilize forward osmosis (FO) membrane technology for this purpose, a high-performance FO membrane (i.e., high nutrients rejection, low reverse solute flux, and high/stable water flux) is needed. It is essential to analyze recent advances in the fabrication/modification of FO membranes for concentrating nitrogenous compounds such as ammonium in wastewater in order to find areas of future designs and developments which is the aim of this study. This work briefly reviews/summarizes the application and rejection rates of commercially available cellulose triacetate FO membranes and thin film composite FO membranes as well as self-made or chemically modified membranes used in several research studies to remove/recover ammonium from various wastewaters/feed solutions under different operating conditions. Surface modification can be applied to fabricate ammonium selective FO membranes.