Solid-Phase Extraction of Pb (II) Ions Based on L-Cysteine Functionalized Fe3O4/SiO2 Core-Shell Nanoparticles

Abstract

A paramagnetic solid-phase nanoextractant, L-Cysteine functionalized Fe3O4/SiO2 (FSAC), was assembled for separating Pb2+ from wastewater. L-Cysteine molecules were fixed on the surface of Fe3O4/SiO2 nanoparticles by aminopropyl-silane. The properties of the nanoextractant were characterized by Fourier transform infrared spectroscopy (FTIR), a transmission electron microscope (TEM), and a vibrating sample magnetometer (VSM). It was shown that FSAC particles are sphere-like, are 20 nm in size, and have good paramagnetic properties. The FSAC nanoextractant shows good adsorption, excellent adsorption kinetics, wide acidic resistance, and high saturated adsorption capacity beyond 234 mg·g−1, reached within 30 min. The applied nanoextractant can be completely recovered in a 1.0-M HCl/0.5% thiourea mixing solution within 5 min, but maintain over 92% adsorption when recycled 6 times.