Superparamagnetic Fe₃O₄@EDTA nanoparticles as an efficient adsorbent for simultaneous removal of Ag(I), Hg(II), Mn(II), Zn(II), Pb(II) and Cd(II) from water and soil environmental samples

In this study, a new and high efficient superparamagnetic nanosorbent, EDTA functionalized Fe₃O₄ nanoparticles was synthesized and used for the adsorption and removal of some heavy metals from environmental samples. The properties of synthesized magnetic nanoparticles were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD). After the adsorption process, the separation of Fe₃O₄@EDTA nanoparticles from the aqueous solution was simply achieved by applying an external magnetic field. The effects of different variables on the adsorption efficiency were investigated simultaneously using an experimental design. The variables of interest were the amount of magnetic Fe₃O₄@EDTA nanoparticles, pH and adsorption time. Box–Behnken design (BBD) combined with desirability function (DF) was applied to find the experimental conditions providing the highest global adsorption efficiency. Under the optimum conditions, the adsorption efficiencies and capacities of superparamagnetic Fe₃O₄@EDTA nanoadsorbents toward Ag(I), Hg(II), Mn(II), Zn(II), Pb(II) and Cd(II) were in the range of 96–104% and 71–169 mg g^− 1, respectively. Average adsorption efficiency and capacity for simultaneously removal of target ions were ≥ 99% and ≥ 112 mg g^− 1, respectively. The results revealed that the applied nanoadsorbent could be used as a high efficient, fast regeneration, reusable and cost-effective material for the removal of heavy metal ions from environmental water and soil samples.