Fluoride and Arsenite Removal by Adsorption on La2O3-CeO2/Laterite

Abstract

In the present article, the adsorbent prepared from laterite with lanthanum and cerium oxides (La2O3-CeO2/laterite (LCL)) was efficiently employed for the removal of arsenite and fluoride from an aqueous environment. The obtained materials were characterized by XRD, SEM, and nitrogen adsorption/desorption. The synthesized LCL exhibited a high adsorption capacity towards arsenite (As(III)) and fluoride. The adsorption of both analytes on LCL, which was well-fitted to a pseudo-second-order equation, was found to be kinetically fast in the first 20 minutes and reached equilibrium at around 180 minutes. Weber’s intraparticle diffusion model in multilinearity using the piecewise linear regression combined with Akaike’s criteria was addressed. The adsorption capacities of LCL calculated from Langmuir’s isotherm model were found to be 67.08 mg·g-1 for arsenite and 58.02 mg·g-1 for fluoride. Thermodynamic parameters presented an endothermic nature of arsenite adsorption but an exothermic nature for fluoride and a negative Gibbs free energy for the spontaneous process of arsenite or fluoride adsorption at the studied temperature range. The excellent adsorption performance and stability make the composite of laterite and La-Ce binary oxides an alternative efficient and cheap adsorbent for the removal of arsenite and fluoride in an aqueous solution.

Screening of Metal Oxides and Hydroxides for Arsenic Removal from Water Using Molecular Dynamics Simulations

“…The framework and simulation basis for structure construction, geometry optimization, validation, and surface building are addressed in Section , while Section outlines the sorption loading, and adsorption capacity calculations and empirical modeling are included in Section . The adsorption capacities of 15 materials were determined using MS software employing Monte Carlo simulations. , Ferric oxyhydroxide (goethite, FeOOH), ferric oxide (hematite, Fe 2 O 3 ), ferrous ferric oxide (magnetite, Fe 3 O 4 ), aluminum oxide (Al 2 O 3 ), titanium dioxide (TiO 2 ), aluminum hydroxide Al­(OH) 3 , zirconium oxide (ZrO 2 ), silver oxide (Ag 2 O), lanthanum oxide (La 2 O 3 ), stannic oxide (SnO 2 ), lanthanum hydroxide (La­(OH) 3 ), tin oxide (SnO), zinc oxide (ZnO), ferrous oxide (FeO), and silicon oxide (SiO 2 ) were chosen for arsenic adsorption based on their application in the field of water treatment. ,,,,,− …”