Synthesis and characterization of magnetic composite for removal of cd (II) from the aqueous medium

Full text: The treatment of wastewater containing cadmium is of great interest because of its persistence in the environment and the serious diseases that it can cause to humans. With the increasing wastewater generation it is essential to study alternatives and to develop new treatment technologies that are economically viable and meet the limits of existing laws for cadmium disposal.The manganese oxide is one of the most effective adsorbent in removing trace metal contaminants from aqueous systems, due to its high adsorption capacity, selectivity and natural abundance.In the present work, the magnetic composite Mn₃O₄/Fe₃O₄ was used as adsorbent of Cd²⁺ in aqueous medium. The adsorbent material was synthesized and characterized according to the XRD with the Rietveld method, TEM and BET techniques. The adsorption study was carried out varying the aqueous medium pH and the concentration of cadmium ions in solution. The results show that the cadmium removal by the Mn₃O₄/Fe₃O₄ magnetic composite in aqueous medium is pH-dependent duplicating as the pH varies from 3 to 7. The study of immobilization of the contaminant in solution showed significant amounts of adsorption, 12.3 mg_Cd/g at pH 6 and 13.6 mg_Cd/g at pH 7 indicating a removal of up to 98% for low ion concentrations and suggesting that the adsorbent has a high potential for removing Cd(II) in aqueous medium. References: G. C. Silva, F. S. Almeida, A. M. Ferreira, V. S. T. Ciminelli, M. S. S. Dantas. Acta Part A. 100, (2013) 161-165. G. C. Silva, V. S. T. Ciminelli, A. M. Ferreira, N. C. Pissolati, P. R. P. Paiva, J. L. López, Mater. Res. Bull. 49, (2014) 544-551. (author)