Forward Osmosis for Sustainable Brackish Water Desalination

The desalination of brackish and seawater has emerged as a critical strategy to address growing water scarcity in regions experiencing water stress, particularly within the context of sustainable water resource management. Among available technologies, forward osmosis (FO) has gained increasing attention due to its potential for lower energy consumption and reduced environmental impact compared to conventional desalination processes. In this study, commercial HFFO2 (Aquaporin Inside) membrane from FO was used. A complete factorial design with three factors was used: feed solution concentration (1.5 and 3 g/L NaCl), draw solution concentration (15, 25, and 35 g/L NaCl), and feed solution flow rate (600 and 1000 mL/min) on the percentage of recovery and water flux. Tests showed that as the feed concentration decreases from 3 to 1.5 g/L of NaCl, water recovery improves by 23.6%. The results revealed that increasing the concentration of the draw solution from 15 to 25 g/L of NaCl increased water recovery by 22.2%. However, for a concentration variation of 25 to 35 g/L, this increase is insignificant at 0.92%. The results showed that, with a concentration of 1.5 g/L of NaCl, a feed flow rate of 1000 mL/min, and a concentration of 25 g/L of NaCl as the draw solution, a higher water recovery rate (95.4839%) was achieved. Similarly, average water flux values of 2.18, 2.43, and 2.68 Lm−2h−1 were observed when using draw solutions of 15, 25, and 35 g/L of NaCl, respectively. In addition, increasing the FS flow rate slightly reduces water recovery (from 76.04% to 74.06%). Consequently, the forward osmosis process has proven to be effective, practical, viable, and environmentally friendly for water desalination, as well as being applicable to the treatment of wastewater with high electrical conductivity.