Effect of magnetite on the adsorption behavior of Pb(II), Cd(II), and Cu(II) in chitosan-based hydrogels

► Chitosan-based hydrogel with and without magnetic property for removing heavy metals. ► The water diffusion mechanism favors the adsorption of heavy metals. ► Magnetite may affect both the water diffusion mechanism and the adsorption of metals. ► Magnetic hydrogel and metals may be recovered applying a remote magnetic field.