Main content area

Selective removal of tungstate anions from aqueous solutions by surface anion‐imprinted ceramic membranes

Dong, Zhihui, Zeng, Jianxian, Zhou, Hu, Lv, Chaoqiang, Ma, Yichang, Zeng, Jiehui
Journal of chemical technology and biotechnology 2019 v.94 no.3 pp. 942-954
Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, anions, aqueous solutions, binding capacity, ceramics, chromium, electrostatic interactions, filtration, molybdenum, pH, porosity, scanning electron microscopy, technology, thermogravimetry
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 (Qₑ) of W(VI) onto IIP‐PEI/CM and non‐imprinted membrane (NIP‐PEI/CM) rapidly decreased. At pH = 2.0, Qₑ 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. © 2018 Society of Chemical Industry