Preparation of a forward osmosis membrane using a highly porous polyketone microfiltration membrane as a novel support

Forward osmosis (FO) membrane processes have attracted much attention because of their versatile potential in water treatment applications. However, further development of FO membranes is required to make them suitable for advanced FO applications. In this study, we used polyketone porous membranes as a novel support layer for the fabrication of thin-film composite (TFC) FO membranes. Highly porous polyketone membranes were prepared by phase separation and subsequent interfacial polymerization was carried out on the polyketone membrane surface. The prepared TFC-FO membranes showed excellent osmotically driven performance with one of the highest water fluxes in those of commercially available FO membranes because of the lower structural parameter (S-value) of less than 300μm. The comparison of five types of prepared and three types of commercial FO membranes provided an understanding of the impact of the support layer structure on osmotically driven membrane performance when internal concentration polarization is involved. By tuning the porosity and pore size near the active layer, we successfully prepared an FO membrane with high performance, which showed a water flux exceeding 29.3Lm^-2h^-1 with 0.065molm^-2h^-1 reverse salt flux in the AL-FS orientation when 0.6M NaCl solution and pure water were used, respectively, as the draw and feed solutions.