Reusable Magnetic Nanoparticle Immobilized Nitrogen-Containing Ligand for Classified and Easy Recovery of Heavy Metal Ions

Abstract

Functionalized Tris[2-(dimethylamino) ethyl] amine (Me₆TREN) ligands tethered-Fe₃O₄@Me₆TREN nanoparticles (NPs) with a size of 150 nm were prepared to achieve classified and easy recovery of heavy metal ions in wastewater. The preparation of such NPs related to sequential silane ligand exchange and a following cure and Schiff base reactions for Fe₃O₄ NPs. Fe₃O₄@Me₆TREN NPs as an effective nano-adsorbent of heavy metals exhibited significant differences in maximum adsorption capacity for Cr(III) (61.4 mg/g), Cu(II) (245.0 mg/g), Pb(II) (5.3 mg/g), and Cd(II) (1136.2 mg/g), in favor of classified removal of heavy metals from wastewater. Furthermore, Fe₃O₄@Me₆TREN NPs can be regenerated by desorbing metal ions from NP surfaces eluted with ethylenediaminetetraacetic acid disodium salt (EDTA-Na₂) aqueous, which endows such NPs promising potency as new nano-vectors for the removal of heavy metals.