Enhanced sorption of radiocobalt from water by Bi(III) modified montmorillonite: A novel adsorbent

► Bi-Mt has higher surface area than Ca-Mt. ► The sorption of Co(II) on Bi-Mt is dependent on ionic strength and pH. ► The sorption of Co(II) on Bi-Mt is an spontaneous and endothermic process. ► Bi-Mt has good practical application potential in wastewater disposal.