Improving water flux of UiO-66 immobilized on ceramic hollow fiber

Abstract

The study focused on the development of a modified membrane using a zirconium-based metal–organic framework (UiO-66) to enhance the desalination process in the membrane distillation system. UiO-66 was successfully synthesized on an alumina hollow fiber before fluoroalkylsilane grafting. The effect of UiO-66 concentration loading during membrane fabrication was examined concerning membrane porosity, performance, wettability and surface roughness. Hydrophobic UiO-66 membranes with a contact angle ranging from 130.9° to 139.1° were obtained. The modified membranes were tested in direct contact membrane distillation. With increasing UiO-66 concentration, water fluxes increased from 1.30 to 12.01 kg/m2∙h, and the membrane with 0.4 M of UiO-66 achieved the highest water flux. The optimum membrane was further evaluated under direct contact membrane distillation for seawater desalination to investigate performance stability. The membrane demonstrated a water flux of 9.26 kg/m2∙h with 100 % salt rejection. Moreover, the membrane powder maintained its crystallinity in seawater, demonstrating its long-term stability and substantial capabilities in terms of desalination.