Heavy Metals [Chromium (VI) and Lead (II)] Removal from Water Using Magnetite (Fe3O4) Nanospheres

Abstract Magnetite nanospheres with hollow interiors were synthesized using a simple, one-pot, and template free solvothermal method with ferric chloride as the iron precursor. The composition, surface properties and morphology were studied using X-ray powder diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF), Fourier transform infrared spectroscopy (FTIR), surface area analysis, point of zero charge (pHpzc), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and magnetic moment determination. These mesoporous nanospheres have a SBET = 11.3 m2/g and a high saturation magnetization These magnetite nanospheres successfully remediated Cr6+ and Pb2+ from water. Adsorption was carried out at diffrent tempratures. The sorption data were fitted using Freundlich, Langmuir, Redlich-Peterson, Sips, Koble-Corrigan, Radke and Prausnitz and Toth adsorption models. The pseudo-second order model better fitted the kinetics data. The Langmuir adsorption capacities of magnetic nanospheres were ~9 and ~19 mg/g for Cr6+ + and Pb2, respectively. Magnetic collection of these magnetite nanospheres can be used to isolate and regenerate the used adsorbent. Keywords: Magnetite hollow nanospheres, solvothermal method, mesoporous, sorption, lead and chromium removal