Assessment of Performance of Inorganic Draw Solutions Tested in Forward Osmosis Process for Desalinating Arabian Gulf Seawater

Gulf Cooperation Council countries are mainly depending on Arabian Gulf Seawater (AGS) for the production of fresh water through desalination technologies. This paper aims to provide valuable information and data on the performance of the NaCl draw solution (DS) for desalting of AGS using forward osmosis (FO) technology. The tests were conducted on a laboratory scale using commercial thin-film composite (TFC) FO membrane to evaluate the FO performance in terms of water flux, water recovery and reverse salt flux. For comparison, the FO performance data were explored using DI water, and AGS from beach well (TDS similar to 45,000 ppm) as feed solutions, while the DS consisted of NaCl, calcium chloride and magnesium chloride. The results showed that for AGS as feed, water flux of 5.7, 3.7 and 3.5 L/m(2)h was attained with NaCl, CaCl2 and MgCl2 DS, respectively. The highest water recovery of 37.6% was achieved using NaCl as DS, attributed to its high degree of solubility and low molecular weight compared to CaCl2 and MgCl2. The study demonstrated the benefits of selected TFC membrane towards AGS desalination considering NaCl as effective DS.