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

合成了磁性粘土（MtMag）和磁性有机粘土（O100MtMag）纳米复合材料，表征并评估了砷的吸附。在不同的pH条件和初始As（V）浓度下进行了分批砷吸附实验，同时进行了连续的吸附循环以评估材料的再利用性。发现最高的As（V）去除效率（MtMag和O100MtMag分别为9±1 mg g ^-1和7.8±0.8 mg g ^-1），在中性和碱性条件下降低。从As（V）吸附等温线，区分了两个吸附过程或两个不同的表面位置。由蒙脱石或有机蒙脱石和磁铁矿作为主要的铁氧化物组成的纳米复合材料，饱和磁化强度为8.5±0.5 Am² Kg ^-1（MtMag）和20.3±0.5 Am ² Kg ^-1（O100MtMag）。因此，可以使用外部磁场从水溶液中分离并回收两种材料。在连续两个吸附周期（MtMag和O100MtMag分别为2.25和4.5μgL ^-1）后，两种材料均实现了低于世界卫生组织（WHO）建议浓度极限的砷浓度。