Enhanced Removal of Cr (VI) by PEI/nFe3O4 Ultrafiltration Membranes Using Peristaltic Pump-Driven Dynamic Adsorption

In this study, Fe3O4 nanoparticles (nFe3O4) were loaded onto polyvinylidene fluoride ultrafiltration membranes and capped with polyethyleneimine in order to form PEI/nFe3O4 ultrafiltration membranes. We used a peristaltic pump as a driver for dynamic adsorption, and the PEI/nFe3O4 ultrafiltration membrane had a good ability to remove hexavalent chromium (Cr(VI)) from wastewater. The full permeate volume of the PEI/nFe3O4 ultrafiltration membrane was maximized at pH 3. Meanwhile, the removal of Cr(VI) from the wastewater reached 98% and reduced to trivalent chromium (Cr(III)). When the initial concentration of Cr(VI) increased, the active sites on the membrane would be filled and the removal efficiency of Cr(VI) would decrease. Meanwhile, the coexisting ions affect the removal efficiency of Cr(VI), and PO43- has a strong negative effect on the removal efficiency. PEI/nFe3O4 ultrafiltration membrane is an effective combination of multifunctional nanomagnetic materials and membrane materials, which can effectively remove hexavalent chromium from wastewater. The study provides a basis for future applications in the environmental remediation of low-concentration chromium-containing wastewater.