Synthesis and characterization of Cysteine-functionalized Fe3O4 nanoparticles and its application in removal of heavy metals from waste waters in south pars gas complex

Magnetic iron oxide nanoparticles (MNPs) were functionalized with Cysteine, by a cost effective and environmentally friendly procedure, as an alternative route to typical thiol and amine functionalized polymeric coatings. MNPs were synthesized by co-precipitation method and adsorption of Cysteine was investigated as a function of ligand concentration and pH. The as-synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electronic microscopy (SEM) and FT-IR spectroscopy techniques. The thiol-amine functionalized Fe3O4 nanoadsorbent exhibited high adsorption affinity for aqueous Cd(II), Cu(II), and Pb(II) ions, resulting from complexation of the metal ions by surface thiol and amine groups. Factors influencing the uptake of heavy metal ions such as solution pH, initial metal ion concentration, contact time, and species of metal ions were investigated systematically by batch experiments. The nanoadsorbent was able to remove over 95% of Cd(II), Cu(II), and Pb(II) in 40 mL of solution containing 4 mg/L metal ions at optimized conditions which is larger than some other reports [1,2]. The adsorption rates of Cd(II), Cu(II), and Pb(II) on this nanoadsorbent fit pseudo-second order kinetic models (R2 0.99). Furthermore, these nanoadsorbents can be used as highly efficient separable and reusable materials for removal of heavy metal ions from waste waters.