Nanostructure Iron(III)−Zirconium(IV) Binary Mixed Oxide: Synthesis, Characterization, and Physicochemical Aspects of Arsenic(III) Sorption from the Aqueous Solution

Abstract

Characterization of synthetic Fe(III)−Zr(IV) mixed oxide (NHIZO) by the X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses confirmed the material as agglomerated nanocrystallite particles (16−21 nm) which was used for As(III) sorption from water. The optimum pH and equilibrium time (As(III) concentrations (mgL−1), 5.0 and 10.0; NHIZO dose, 2 g·L−1; temperature, 303 K) were 7.0 ± 0.2 and 2.0 h, respectively. The kinetic and equilibrium data described, respectively, the pseudo-second-order equation and the Langmuir as well as the Redlich−Peterson isotherm models very well. The Langmuir capacity was 65.5 ± 1.0 mg·g−1 at 303 K, which increased with increasing temperature. The positive enthalpy (ΔH°) and negative free energy (ΔG°) changes indicated the endothermic and spontaneous nature of the reaction, respectively. The sorption energy (4.64−5.20 kJ·mol−1) and Fourier transform infrared (FTIR) analyses suggested physissorption of As(III) by NHIZO. ...