Study of Pb Ions Removal from Aqueous Solutions by a Novel Sodium Formate-Coated Magnetite Nanoparticles

Abstract

One of the problems that continuously happen from the past ages till the present time is the contamination of the water sources with heavy metal ions; as a continuation of the many studies have been done so far to solve this problem. Novel magnetite nanoparticles (NPs) coated with sodium formate (SF-Ni0.31Mg0.15Ag0.04Fe2.5O4)have been prepared using co-precipitation method. Characterization of the prepared SF-magnetite NPs was done by using the spectroscopic devices (XRD), (SEM), (EDX), (FT-IR), and (AAS). From the XRD spectrum it was found that the crystal structure of the prepared SF-magnetite NPs is a cubic inverse spinel structure, which has average crystallite size, the lattice constant, and X-ray density of 28.57 nm, 8.33 Å, 5.29 g/cm3, respectively. SEM images have shown that the prepared NPs have a sphere-like shape with a measured average crystallite size of 25.93 nm. By EDX spectrum the presence of the constituent elements was confirmed by giving their energy peaks (O: Kα=0.525), (Fe: Kα=6.4, Lα=0.705), (Ni: Kα=7.84, Lα=0.85), (Mg: Kα=1.25), and (Ag: Lα=2.98, Lβ=3.35). The attachment of the SF molecules to the magnetite NPs was proven by the FT-IR spectrum through appearing the absorption peaks in the SF-magnetite NPs spectrum at 1600cm−1 and 3400cm−1 return to the bonds (C=O) and (C-H stretch) in SF. By ASS results, adsorption of Pb ions was clearly influenced by SF coating giving removal rate (93%) at equilibrium time (10min) in the prepared solution of Pb(NO3)2 salt, while for the wastewater samples the removal rate was (55%) - (100%).