Equilibrium and kinetic study of ammonium ion adsorption by Fe3O4 nanoparticles from aqueous solutions

Fe3O4 nanoparticles were used as efficient adsorbent for the quick removal of ammonium ion from the solvent phase. The developed adsorbent was synthesized using a chemical co-precipitation method from its precursor mixtures i.e. FeCl2 center dot 4H(2)O and FeCl3 center dot 6H(2)O and which was further characterized using various analytical techniques such as Transmission electron microscopy and X-ray powder diffraction. The effect of various influential parameters such as contact time, pH, temperature and initial concentration was determined and optimized through a batch adsorption experiment. The optimized values of contact time, pH, temperature and initial concentration for adsorption were found to be 40 min, pH 10, T: 298 K and 140 mg/L of ammonium ions, respectively. The adsorption capacity of Fe3O4 to adsorb ammonium ion in aqueous solution was well investigated and elucidated. The adsorption equilibrium data was found to be well fitted and in good agreement with the Langmuir isotherm model, which clearly depicts the strong interaction between the developed adsorbent and the ammonium ions; which directly leads to the rapid adsorptions of ammonium ion from the aqueous solution. (C) 2015 Published by Elsevier B.V.