Network Polymer Modified Magnetic Silica Nanoparticles for Sustainable Removal and Regeneration of Heavy Metal Ions in Water

Abstract

A network polymer modified magnetic silica nanoparticles (MSNPs) with core-shell structure as absorbent was synthesized using a three-step grafting strategy, where 8-chloroacetyl-aminoquinoline (CAAQ) was employed to fabricate the network polymer coating. The as-synthesized MSNPs-CAAQ nanocomposites possessed abundant active functional groups, and thus exhibited excellent removal feature for heavy metal ions (HMIs). MSNPs-CAAQ nanocomposites had relatively high adsorption capacity of 324.7, 306.8 and 293.3 mg/g for Fe3+, Cu2+ and Cr3+ ions according to the Langmuir linear fitting, respectively. The adsorption-desorption experiment results indicated that Na2EDTA was shown to be more suitable as desorbing agent for the desorption of Fe3+, Cu2+ and Cr3+ ions than HCl and HNO3. MSNPs-CAAQ can be further applied to purify the polluted river mainly including Zn2+, Cu2+, Cd2+, Pb2+, Hg2+, Cr3+ and Fe3+ ions, our results showed that no obvious change was found in the adsorption capacity of MSNPs-CAAQ even after six consecutive adsorption-desorption cycles, implying that the as-synthesized MSNPs-CAAQ was suitable as absorbent for the efficient removal of HMIs from aqueous solution. Furthermore, attributed to the strong magnetic response of MSNPs-CAAQ, this absorbent could facilitate the sustainable removal of HMIs in practical applications.

Keywords: Nanoparticles, Magnetic, surface modification, removal, regeneration, Heavy metal ion