BackgroundRemoving toxic heavy metal ions from water bodies is one of the most important areas of water treatment, and using porous membranes with a chelating function is a good route for this. Graft-type porous membranes with a chelating function are innovate functional membranes. In this work, the main aims are to prepare such a functional membrane and evaluate its adsorption and rejection properties for heavy metal ions in water through adsorption isotherm experiments and permeation experiments. ResultsGlycidyl methacrylate (GMA) was graft-polymerized on the surface of polysulfone (PSF) microfiltration membrane through a surface initiating system, getting the grafted membrane PSF-g-PGMA. Then the ring-opening reaction of the epoxy group of the grafted PGMA was carried out with iminodiacetic acid (IDAA) as reagent, obtaining PSF-g-PGMA/IDAA membrane, on which a great deal of IDAA as chelating ligand was bonded. PSF-g-PGMA/IDAA membrane possesses a strong adsorption ability towards heavy metal ions via the chelating action and electrostatic interaction. The order of adsorption capacity was Pb2+>Cu2+>Cd2+, and the adsorption capacity of Pb2+ ion reached 4.5 mu molcm(-2). When an injection filter with a membrane area of 1.77cm(2) was used, the rejection rate of PSF-g-PGMA/IDAA membrane for the three heavy metal ions with concentrations of 0.1mmolL(-1) were maintained at a level of 95% until the permeation solution volume reached 100mL. ConclusionThe grafted microfiltration membrane PSF-g-PGMA/IDAA can be easily prepared and possesses excellent rejection and removing performance towards heavy metal ions (c) 2018 Society of Chemical Industry