Adsorption of Chromium (VI) from Polluted Water Using Core/Shell Nano Magnetic Particles of Fe3O4/CoO

Chromium (VI) enters water resources via effluents of metallurgical, chemical pigments, electroplating, and tanning industries. The chromium accumulation in animal and plant tissues can cause serious dangers. In human, chromium (VI) causes damage to liver, kidney, and lung. The aim of this research is the removal of chromium (VI) from water by Fe3O4/CoO nanostructured magnetic adsorbent. In this work, nano magnetic particles of Fe3O4/CoO were synthesized by co-precipitation method and were used for the adsorption of chromium (VI) from water. The Fe3O4/CoO adsorbent was characterized by ICP, XRD, TEM, and VSM methods. Effects of pH on chromium (VI) adsorption on Fe3O4/CoO were studied. The isotherm and kinetics of the adsorption were also studied. TEM images confirmed the formation of the core/shell structure of the nanoparticles. The VSM test showed the magnetic property of the Fe3O4/CoO adsorbent. The experimental data were better fitted to the Freundlich isotherm model. In a batch operation, by using 1.5 g of Fe3O4/CoO adsorbent, 100 mL of chromium (VI) solution with the concentration of 50 mg/L and pH 3, the chromium (VI) removal yield of 89.04% was obtained after 24 hours. The magnetic nanoparticles of Fe3O4/CoO are a good adsorbent to remove chromium (VI) from water with the advantage of easy separation from water by an external magnetic force.