BACKGROUND: It is significantly important to develop new technologies and materials for removal of tungstate anions (W(VI)) from aqueous solutions. An ion imprinted membrane not only possesses all virtues of a separation membrane, but also has tailor-made recognition sites. In this work, a novel surface anion-imprinted ceramic membrane (IIP-PEI/CM) was fabricated to remove W(VI) selectively from aqueous solutions.
RESULTS: FT-IR, XPS, TGA, SEM, streaming potential, pore size distribution and water flux confirmed the successful fabrication of IIP-PEI/CM. With increasing pH, binding capacities (Q e ) of W(VI) onto IIP-PEI/CM and non-imprinted membrane (NIP-PEI/CM) rapidly decreased. At pH = 2.0, Q e values of IIP-PEI/CM and NIP-PEI/CM were 139.4 and 47.9 mg 100 g −1 , respectively. Binding equilibrium was achieved within 3 min, showing an ultra-fast kinetic process. Compared with NIP-PEI/CM, IIP-PEI/CM had higher selectivity for W(VI) in the presence of Mo(VI) and Cr(VI) ions, and its selectivity coefficients for W(VI)/Mo(VI) and W(VI)/Cr(VI) were 15.47 and 19.74, respectively. During dynamic filtration, IIP-PEI/CM was effective and selective for removal of W(VI), and it had a good reusability. Protonated amine groups within PEI participated the uptake of W(VI) by electrostatic interactions. CONCLUSION: IIP-PEI/CM showed ultrafast and selective binding of W(VI) anions, and has potential application for W(VI) removal/recovery from aqueous solutions.