New “Magmolecular” Process for the Separation of Antimony(III) from Aqueous Solution

Abstract

In this work, the separation potential of a new “magmolecular” process for ions of antimony(III) from wastewater was studied. The magmolecular process is a technique in which a high gradient magnetic field is applied to eliminate heavy metal from wastewater. In this process, specifically we have synthesized two nanoadsorbent magnetic materials, MnFe2O4 nanoparticles both uncoated (MNPs) and amino-modified coated (AS-MNPs), and used them to remove antimony(III) from synthetic wastewater. Several variables affecting the adsorption behavior such as pH, contact time, temperature, amount of MNPs and AS-MNPs, initial concentration of antimony(III), and influences of co-ions were studied. The kinetics was exanimated using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion methods. The equilibrium results were evaluated by Langmuir, Freundlich, and Dubinin–Radushkevich equations. The uptake was relatively rapid and followed pseudo-second-order kinetics in a manner suggesting chemical sorption. The best commentary for the adsorption results was obtained by the Langmuir model, and the maximum uptake capacity of MNPs and AS-MNPs was found to be (10.66 and 7.78) mg of antimony(III) per gram adsorbent at conditions of pH 2 and temperature of 298 K, respectively. Thermodynamic factors indicated that the uptake process was endothermic, spontaneous, and chemical in nature. After five uptake–desorption cycles, results showed that uptake–desorption efficiencies of AS-MNPs were better than that of MNPs.