Efficiently selective removal of Pb(II) by magnetic ion-imprinted membrane based on polyacrylonitrile electro-spun nanofibers

Abstract

The development of membrane for heavy metal ion removal in water treatment is still impeded by low adsorption efficiency, poor selectivity, and deficient recyclability, which has gained great interests in both laboratorial research and industrial application. Herein, our aim is to fabricate the magnetic ion-imprinted PAN membranes (MII-PMs) based on polyacrylonitrile electro-spun nanofibers with improved adsorption ability, selectivity, and recyclability for efficient and selective removal of Pb(II) from water. The chemical structure and chemo-physical properties of the as prepared MII-PMs were characterized. Remarkably, in competitive adsorption experiment the MII-PMs demonstrated a much higher adsorption capacity towards Pb(II) than other interfering metal ions with the selective order of Pb2+>Cu2+>Mg2+>Co2+>Ni2+>Cd2+>Zn2+>Na+>K+. In investigation of the adsorption mechanism towards Pb(II), the equilibrium adsorption data of MII-PMs fitted better with Freundlich isotherm equation, and the kinetic parameters matched well with pseudo-second-order mode. In regeneration and reusability experiment, the MII-PMs could be regenerated with eluting solution and displayed good adsorption capacity towards Pb(II) during 6 adsorption–desorption cycles. Only small amount of Fe ions was leached out after the regeneration experiments. Generally, the as prepared magnetic ion-imprinted membrane with improved adsorption capability, high selectivity, and excellent reusability towards Pb(II) ions can be utilized as a promising and efficiently potential adsorbent in actual water treatment.