A new synthesis of Fe1-x-MnxO3/PVA nanocomposites for the removal of heavy metals from water

Abstract

In the present work, an eco-friendly method is used for the synthesis of Fe1-x-MnxO3 nanoparticles and Fe1-x-MnxO3/PVA nanocomposites, where x represents the different concentration of Zanthoxylum armatum extract as a stabilizer. Formation of the respective nanomaterials and their nano-composites were confirmed by UV-visible spectroscopy while surface functionality ere confirmed by Fourier transform infrared spectroscopy. Transmission electron microscopy and X-ray diffraction were used to reveal the surface morphology and crystallinity of the particles. The synthesized materials were then used as adsorbents for removal of Pb(II) and Cr(VI) from aqueous solution. The effect of various parameters like concentration, contact time, and pH of the medium on the adsorption efficiency of the adsorbent was studied. It was found that equilibrium achieved after 20 min while optimum pH for Pb(II) and Cr(VI) was 5 and 3, respectively. The maximum efficiency of the adsorbent (Q(max)) for Pb(II) was 84%, while for Cr(VI) it was 92%. Results demonstrate that Pb(II) and Cr(VI) adsorption onto iron nanoparticles (IONPs) and IONPs/PVA nanocomposites followed the pseudo-second-order kinetics reaction. The adsorption isotherm for Pb was well tailored by the Langmuir adsorption model, while the Cr adsorption was described by the Freundlich adsorption isotherm. The sorption model parameter demonstrates that the synthesized materials can be utilized as an excellent economical nano-adsorbent for removal of Pb(II) and Cr(VI) from water.