Effect of synthetic beidellite structural characteristics on the properties of beidellite/Fe oxides magnetic composites as Sr and Cs adsorbent materials

Abstract

To design more efficient and versatile sorbent materials for wastewater treatment three magnetic beidellite composites with different cation exchange capacity and total specific surface area have been synthetized, characterized and used as Cs+ and Sr2+ sorbents. Total loaded Fe concentration and its distribution on the magnetic composites seems to be related to the total specific surface area. The higher saturation magnetization, 13.7 ± 0.7 Am2/kg, was achieved for the sample with the higher total specific surface area. The main magnetic phases after the synthesis are magnetite and maghemite, whose particle size ranged between 28 and 114 nm, respectively. The Cs+ and Sr2+ sorption capacities of raw and magnetic beidellite composites were similar. The sorption takes place at two different sorption sites of the beidellite composites: the external surface, as indicated by zeta potential changes, and the interlayer space, as revealed by diffraction patterns.