Effect of different inorganic draw solutes on SiNPs-TFN membrane for forward osmosis desalination

Abstract

Forward osmosis (FO) is the most promising upcoming desalination technique which requires more detailed researches to reduce its challenges like low pure water flux and high reverse solute flux. This paper represents the fabrication of thin-film nanocomposite polyethersulfone membrane with 0.005 wt% of silica nanoparticle (SiNPs) loading and analysis of FO performance of the fabricated TFN membrane. The nanoparticle was incorporated into the polyamide active rejection layer by interfacial polymerization. Membrane characterizations like ATR-FTIR, SEM, and wettability analysis were done. Successful nanoparticle incorporation was confirmed by ATR-FTIR analysis. Rise in hydrophilicity of TFN membrane was confirmed surface wettability measurements. The effect on draw solution concentration as well as cross-flow rate on membrane performance was analyzed. Comparison of forward osmosis performance with various inorganic draw solutes was also tested. The draw solutes considered were KCl, NaCl, and CaCl2 due to its various applications in fertigation and desalination. The filtration parameters of the fabricated membranes are analyzed and enlisted. The membrane FO performance under AL-FS and AL-DS modes of operation was tested. Results show that fabricated TFN membrane obtains a maximum flux of 23.93LMH in AL-DS mode, and salt rejection was 91%.