▎ 摘 要
Graphene oxide-polysulfone (GO-PSF) mixed-matrix membranes were prepared by the wet-phase inversion method. The GO content in the membranes was 0.25-2.0 wt%. The membranes were used in direct contact membrane distillation (DCMD) with solutions containing 25,000 mg/L NaCl. The membrane that performed the best was exposed to RO concentrate containing 12,000 mg/L total dissolved solids (TDS). The characterization of GO was studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. The morphology of the membranes was studied using SEM. The porosity of the membranes was determined using Image J analysis of the SEM images. The variation in hydrophobicity was studied by measuring the contact angle of the membranes. The performance of the membranes was determined by measuring the permeate flux and salt rejection. SEM images showed enlarged macrovoids while the contact angle showed that GO addition makes the membrane less hydrophilic than the PSF membrane. The membrane containing 2.0 wt% GO offered the best permeate flux; however, the salt rejection and the porosity was higher with the membrane containing 1.0 wt% GO. This indicates that there is a limit in the amount of GO that can be beneficial to the membrane. The membrane with 1.0 wt% GO gave a flux of 20.8 L/m(2).h and 31.9 L/m(2).h when treating the NaCl solution and RO concentrate, respectively, which indicates that GO may help to retain the excess of ions without compromising the efficiency of the membrane and the quality of the water produced. There is room for improvement of the properties of the GO-PSF membrane to make it adaptable to MD as novel GO-based nano-membrane for the treatment of high salinity water such as RO concentrate and produced water.