Copolymerization of anthranilic acid and o-phenylenediamine by a free radical in the presence of nanoparticles of copper hexacyanoferrates for the removal of cesium ions in aqueous solutions

Abstract

Core–shell nanocomposite of copper hexacyanoferrate copolymer of anthranilic acid with o-phenylenediamine (CHCF-poly-AA-co-OPD)) was synthesized and used as ion exchanger for the removal of cesium ions from wastewater. The nanocomposite was prepared by implantation of CHCF nanoparticles into the copolymer of poly(AA-co-OPD) during the polymerization process. By transmission electron microscope, scanning electron microscope and Brunauer–Emmett–Teller, the surface morphology and the porous structure were investigated. The physicochemical characterization of the prepared core–shell nanocomposite was carried out by FT-IR spectroscopy, XRD and thermogravimetric analysis. As a function in pH, metal ion concentration, shaking time and temperature, the capacity of the CSNC toward cesium ions and the behaviors of the process were studied. The results illustrated that the maximum capacity was recorded 1.35 mmol g−1 at pH 11, 10 mmol L−1 Cs+ and 25 °C. Also, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) isotherms models were studied, in which the data were well fitted with Langmuir model, suggesting that the uptake of Cs+ was monolayer and homogeneous. Also, the adsorption kinetics data were fitted well to pseudo-second-order model. Thermodynamic parameters were calculated in the temperature from 25 to 60 °C, and the data revealed that Cs+ sorption was endothermic, spontaneous and more favorable at higher temperature. Up to 92% desorption of Cs+ was completed with 2 M KCl.