Preparation of Fe3O4@TiO2 blended PVDF membrane by magnetic coagulation bath and its permeability and pollution resistance

Abstract

Fe3O4@TiO2 magnetic photocatalytic particles were synthesized and characterized. A composite PVDF separation membrane blended with Fe3O4@TiO2 particles was prepared by the phase inversion method. The main purpose was to explore the effect of magnetic fields on the performance of membranes during coagulation bath. The structure characterization, permeability, interception ability, and anti-pollution performance of inorganic particle blend membranes were then tested. Results showed that magnetic field coagulation baths have little effect on the pore structure and hydrophilicity of the membrane surface. When the liquid membranes was condensed under a magnetic field, the magnetic photocatalytic particles could migrate at a greater rate to the surface of the membrane. Through performance tests of the PVDF modified membranes, it was found that a magnetic coagulation bath could promote more Fe3O4@TiO2 to aggregate on the surface of the membrane, which led to the blend membrane formed under the magnetic coagulation bath had better antifouling performance against humic acid solution under ultraviolet light irradiation. Membranes with 0.5 wt% magnetic photocatalytic particles in a magnetic field coagulation bath performed best. When filtered under the condition of ultraviolet light, its pure water flux was 1752 L/(m2 h), and the rejection rate of 20 mg/L humic acid solution was 67.17%. The flux attenuation before and after filtration was 38.84%, the flux recovery rate was 91.10%, and the irreversible pollution index was only 8.90%.

Keywords

• PVDF membrane
• Fe3O4@TiO2
• Magnetic coagulation bath
• Photocatalytic
• Membrane fouling