Synthesis of propyl aminopyridine modified magnetite nanoparticles for cadmium (II) adsorption in aqueous solutions

Abstract

In this study, 2‐aminopyridine functionalized magnetite nanoparticles were chemically synthesized and used for removing Cd2+ ions from aqueous solutions. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X‐rays (EDX), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The SEM results showed the synthesized magnetite nanoparticles have particle size around 26 nm. The effects of several variables including solution pH and volume, adsorbent mass, ionic strength and contact time on the Cd2+ adsorption were studied in batch experiments and finally the optimum conditions for adsorption were obtained. The kinetic data were investigated by pseudo‐ first‐order, pseudo‐ second‐order, intraparticle diffusion and Elovich kinetic models and data were described reasonably by pseudo‐ second‐order model (R2 = 0.9996) with qe = 2.31 mg g−1. Adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R2 = 0.9907). After study the possible interference effect of foreign ions on Cd2+ removal, the applicability of the proposed nanoparticles for adsorption from real samples confirmed the successfully removal of Cd2+ ions with removal efficiency higher than 92%. The obtained results showed that the synthesized nanoparticles as a reusable adsorbent can act as a good choice for Cd2+ removal with an easy procedure.