Novel kinetic model of the removal of divalent heavy metal ions from aqueous solutions by natural clinoptilolite

► A novel kinetic model for heavy metal removal by natural clinoptilolite. ► Two-step reaction in zeolite lattice: release of Na+ followed by M2+ bonding. ► Kinetics of Cu(II), Mn(II), Zn(II) and Pb(II) removal from aqueous solutions. ► Kinetic constant of Na+ release is not influenced by different metals. ► Kinetics prediction requires only one experimentally determined parameter.