Immobilization of As(III) in soil and groundwater using a new class of polysaccharide stabilized Fe-Mn oxide nanoparticles

► We prepared a new class of stabilized Fe-Mn binary oxide nanoparticles for arsenic immobilization in soil and groundwater. ► The nanoparticles can be delivered into porous media and the transport can be manipulated. ► The delivered nanoparticles will remain immobile and serve as a permanent sink for immobilizing arsenic. ► Amending As-laden soil with the nanoparticles reduced leachable arsenic by more than 90%.