Synthesis and characterization of novel thin film composite forward osmosis membrane using charcoal-based carbon nanomaterials for desalination application

Abstract

In this study, charcoal-based carbon nanomaterial (CNM) was used to modify thin film composite (TFC) membranes for forward osmosis (FO) process. Different amounts of CNM were incorporated into polyethersulfone (PES) and the effects of CNM addition on hydrophilicity, roughness, and morphology of the prepared substrates were investigated. To fabricate the TFC-FO membranes, m-phenylenediamine (MPD) and trimesoyl chloride (TMC) were used for polyamide (PA) layer formation on the substrate surface. FO performance of the prepared TFC membranes was evaluated in both FO and pressure retarded osmosis (PRO) modes using deionized (DI) water as feed solution (FS) and 1 M NaCl solution as draw solution (DS). Also, to study the TFC membranes capability for desalination purposes, the Caspian Seawater was used as FS. It was found that incorporation of CNM into the TFC membrane substrate leads to the reduced structural parameter (S), significantly. The membrane containing 0.5 wt% CNM showed the best performance with water flux of 12.08 and 32.25 L.m−2.h−1 (LMH) in FO and PRO modes, respectively (approximately 3 times higher than that for the neat membrane). Also, Js/Jw value significantly reduced from 1.40 to 0.25 g/L. This research demonstrated that charcoal-based CNM is a proper candidate for modification of the TFC-FO membranes to achieve high water flux and selectivity.