Adsorption of iodide from an aqueous solution via calcined magnetite-activated carbon/MgAl-layered double hydroxide

[Display omitted] •A novel calcined magnetite-activated carbon/ MgAl-LDH (MAC/MgAl-LDO) was prepared and characterized.•The low concentration I− was efficiently removed by MAC-MgAl-LDO through “ memory effect ”.•The adsorbent could be easily separated by the external magnetic field to achieve the resue.•The results may provide a new strategy for treatment of wastewater in nuclear medicine. Calcined magnetite-activated carbon/MgAl-layered double hydroxide (MAC/MgAl-LDO) was prepared using the coprecipitation method and then applied as an adsorbent to separate low-concentration iodide (I−) from an aqueous solution. The physicochemical characterization and adsorption properties of MAC/MgAl-LDO were investigated. MAC/MgAl-LDO has a high saturation magnetization (20.12 emu g−1). The adsorption equilibrium was reached at 6 h, and the corresponding adsorption efficiency was 86%. The adsorption efficiency was still 81% after the 5th reuse. The adsorption efficiency of MAC/MgAl-LDO increased by 52% relative to the uncalcined composites, mainly due to the “memory effect”. This study provides new insights for treating medical iodine wastewater.