Spherical iron oxide methyltrimethoxysilane nanocomposite for the efficient removal of lead(II) ions from wastewater: kinetic and equilibrium studies

In this study, synthesis of iron oxide doped methyltrimethoxysilane (Fe2O3-MTMOS) spherical magnetic nanocomposite was reported, based on the simple methodology for the enhanced removal of lead ions from wastewater. The synthesized magnetic nanocomposites were comprehensively characterized by using Fourier transform infrared spectrometer, field emission scanning electron microscope, X-ray diffraction, and energy dispersive X-ray spectroscopy. Fe2O3 -MTMOS nanocomposite was then employed as an adsorbent for lead (Pb2+) and various adsorption parameters, such as pH, adsorbent dosage, contact time, and initial lead (Pb2+) ions concentration were analyzed and optimized. Adsorption process has been validated with different kinetic and isotherm model, where the experimental data was found to be in good agreement with pseudo-second-order (R-2 = 0.986) and Freundlich isotherm (R-2 = 0.993) as compared with other models. The adsorption capacity of the spherical Fe2O3-MTMOS nanocomposite was found to be relatively higher (105.5mg g(-1)) for lead ions. Adsorption isotherm, kinetic model, and free energy models predicted multilayer sorption pattern for lead ions onto spherical Fe2O3-MTMOS under physical adsorption forces.