Arsenate removal from aqueous solution by montmorillonite and organo-montmorillonite magnetic materials

Abstract Magnetic-clay (MtMag) and magnetic-organoclay (O100MtMag) nanocomposites were synthesized, characterized evaluated for arsenic adsorption. Batch adsorption experiments performed varying pH conditions initial As(V) concentration, while successive cycles made in order to evaluate the materials reuse. The highest removal efficiency (9 ± 1 mg g?1 7.8 ± 0.8 mg g?1 MtMag O100MtMag, respectively) was found at 4.0, decreasing neutral alkaline conditions. From isotherm, two processes or different surface sites distinguished. Nanocomposites resulted composed by montmorillonite organo-montmorillonite magnetite as principal iron oxide, with saturation magnetization of 8.5 ± 0.5 Am2 Kg?1 20.3 ± 0.5 (O100MtMag). Thus, both could be separated recovered from aqueous solutions using external magnetic fields. Both allowed achieving concentrations lower than World Health Organization (WHO) recommended concentration limit after consecutive (2.25 4.5 ?g L?1 respectively).