MnFe2O4/chitosan nanocomposites as a recyclable adsorbent for the removal of hexavalent chromium

Magnetic MnFe2O4/chitosan nanocomposites (MCNCs) were prepared by a simple method. The as-prepared sample was characterized by various technologies. Results indicated that the MnFe2O4 nanoparticles were coated by chitosan without phase change, and the as-prepared MCNCs displayed superparamagnetic properties with a high saturation magnetization (39.5 emu g−1). The as-prepared MCNCs were used to remove Cr(VI) from low concentration solutions (0.6–1.0 mg L−1). And it was found that the MCNCs showed a high Cr(VI) removal capacity of 35.2 mg g−1. The effects of various parameters, such as pH, temperature, agitation time, and initial concentration on the adsorption performance were investigated. The experimental data were well described by the pseudo-second-order kinetics and Freundlich isotherm model. Taking advantages of the high adsorption capacity and quick magnetic separation from treated water, the MCNCs can be regarded as an efficient magnetic adsorbent for Cr(VI) removal from aqueous solution.