Graphene oxide incorporated cellulose triacetate/cellulose acetate nanocomposite membranes for forward osmosis desalination

This paper deals with the effect of acetic acid (AA) as a pore-forming additive and as the polymeric improvers in the casting mixture of cellouse triacetate/cellouse acetate (CTA/CA) blend flat sheet membrane using phase inversion procedure. Graphene oxide sheets (GO NSs) were selected to enhance the membrane performance for forwarding osmosis (FO) application in saline water desalination. The surface properties and morphology of synthesized FO membranes were also considered using contact angle, porosity measurements, FTIR spectroscope, mechanical stability, and SEM. The average contact angles for the neat CTA/CA, AA/CTA/CA, and GO/AA/CTA/CA NC modified membranes were 71 degrees +/- 2, 63 degrees +/- 2.5, and 49 degrees +/- 1.8 and the porosity displayed about 47 +/- 2.5%, 49 +/- 3%, and 62 +/- 2.8%, respectively. The GO/AA/CTA/CA NC modified membrane with lower content of GO NSs (0.4 wt%) showed a higher water flux (33.6 L/m(2).h), salt rejection (99.88%), and lower reverse solute flux (1.45 g/m(2).h), when compared to the neat CTA/CA and AA/CTA/CA membranes using 0.1 M NaCl as feed solution (FS) and 1 M NH4Cl as a draw solution (DS). The influences of various fertilizer draw solutions are also studied. The results reveal that the GO/AA/CTA/CA NC modified membrane showed the highest water flux using 1 M from different fertilizer draw solutes (DFDS) include KCl and NH4Cl (20.5 L/m(2).h) and followed by (NH4)(2)SO4 (20.2 L/m(2).h) and K2HPO4 (18.1 L/m(2).h) as draw solutions (DS) under the FO approach and using a natural saline water sample collected from the Mersa Matruh area, North-Western Coast of Egypt with salinity 12760 mg/L and PH (8.5) as feed solution (FS). The reusabil-ity test of the synthesized GO/AA/CTA/CA NC modified membrane showed good sustainability during the 1260 min continuous test. The FO application displayed a great potential to be in saline water desalination and enhanced water source sustainability to use in agriculture. (C) 2021 Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

This study investigated the effects of using acetic acid and graphene oxide sheets in the preparation of cellulose triacetate/cellulose acetate blend membranes for forward osmosis applications in desalination. The modified membranes displayed improved water flux and salt rejection compared to the neat membranes. The results also showed that the modified membrane had good sustainability and potential for use in agriculture.