Application of β -Cyclodextrin-Modified/PVDF Blend Magnetic Membranes for Direct Metal Ions Removal from Wastewater

Herein, a composite membrane was synthesized by adding β-cyclodextrin modified Fe3O4/GO (β-MGO) to polyvinylidene fluoride (PVDF), in the presence or absence of magnetic field via the combination of magnetic field induction and phase conversion techniques. FT-IR, Raman, XRD, TEM, XPS and hysteresis loop results indicate β-MGO was synthesized successfully. By analyzing the characterization results of the membrane, β-MGO can be adsorbed onto the surface of the membrane under magnetic field (M-β-MGO) conditions. The changes of pure water flux, BSA rejection, hydrophilicity, porosity, pore size and anti-pollution performance of M-β-MGO and β-MGO membrane were discussed with the content of β-MGO. The M-β-MGO membrane shows the best performance when the β-MGO content is 0.7%. In addition, our experimental results on the removal of heavy metal Cu2+ show that after five cycles, the rejection rate and adsorption capacity of Cu2+ are still as high as 75% and 0.94 mg/g. Meanwhile, it is find that pH > 6 can significantly increase the removal rate of Cu2+, and the membrane is suitable for removing Cu2+ concentrations below 30 mg/L. Therefore, this study presents a novel strategy for developing high-performance hybrid membranes via manipulating the migration of nanomaterials to the membrane surface.