Synthesis of Novel Ionic Liquid Modified AC-Fe3O4 Magnetic Nanocomposite for the Adsorption of Heavy Metals in Wastewater

Abstract

This study reports a novel magnetic nanoadsorbent prepared from magnetite (Fe3O4) as the magnetic core, activated carbon from coal fly ash and an ionic liquid (1-methyl-3-ethylimidazolium chloride). The magnetic nanoadsorbent was synthesized via co-precipitation and characterized by FTIR, XRD, TEM, EDS and BET surface area analysis. Batch adsorption studies on cadmium (Cd2+) and lead (Pb2+) solutions such as effect of pH, contact time and adsorbent dosage were carried out. The data was analyzed using the Langmuir and Freundlich models. The results revealed that the optimal adsorption conditions for both metal ions on synthesized nanoadsorbent were pH 6, 200 min, adsorbent dosage of 1.5 g/L, initial ion concentration of 10 ppm and a temperature of 25 ºC. The data obtained in the adsorption of Cd2+ and Pb2+ best fitted the Freundlich isotherm, with R2 values of 0.998 and 0.995, respectively. Thermodynamic and kinetic studies suggested that adsorption of both metal ions on the IL-AC-Fe3O4 nanocomposite followed the pseudo first order model. The synthesised nanoadsorbent (IL-AC-Fe3O4) exhibits good adsorption properties and has great potential in a water treatment technology.