Feasibility study of CAU-1 deposited on alumina hollow fiber for desalination applications

This work investigated the feasibility of a metal–organic framework (MOF), Christian-Albrechts-University (CAU-1), deposited on alumina hollow fiber for desalination applications. CAU-1 membranes, synthesized using the solvothermal approach, were characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and contact angle measurement. The performances of the CAU-1 membranes were tested using forward osmosis (FO). Using a configuration of active layer facing feed, the CAU-1 membrane (M6) had the highest flux of 18 L m−2 h−1 with a reverse solute value of 0.079 kg m−2 h−1. The M6 membrane was further tested using a configuration of active layer facing draw. Surprisingly, the flux moved from the high salt concentration to low salt concentration, obeying the reverse osmosis phenomenon under low pressure. At 10,000 ppm of salt concentration, M6 membrane showed solute fluxes of 4.07 and 3.07 L m−2 h−1 for NaCl and MgSO4 with rejections of 75% and 65%, respectively. Guest molecules and an amine group in CAU-1 were responsible in affecting the performance of the membrane for desalination application.