COMPARISON OF MEMBRANE MATERIALS FOR MEMBRANE DISTILLATION OF TREATING IMPAIRED WATER

摘要

Membrane distillation (MD) is a thermal-driven membrane technology to produce freshrnwater from seawater or contaminated water. Although MD has potential for many applicationrnareas, novel membrane materials for MD processing are required to improve the energyrnefficiency and water production rate.rnIn this study, various microporous membranes with hydrophobic surfaces were compared forrnMD processing. Flat sheet membranes made of PVDF and PTFE were used for laboratory-scalernexperiments. In addition, carbon-nanotube were used as a new materials for MD.rnResults from initial comparison of water flux through MD membrane show that the waterrnflux per unit temperature gradient was approximately proportional to hydrophobicity of thernmembrane materials. CNT-based membranes seem to have potential to compete withrncommercial-grade MD membranes in terms of water flux and salt rejection. When applied tornimpaired water sources, fouling due to particle deposition and organic adsorption may bernanticipated due to the hydrophobic nature of most MD membranes. In addition, the effect ofrnoperating parameters such as flow velocity and temperature difference on MD efficiency wasrninvestigated.