Bench-scale injection of magnesium hydroxide encapsulated iron nanoparticles (nFe0@Mg(OH)2) into porous media for Cr(VI) removal from groundwater

•Injecting Mg(OH)2 encapsulated iron nanoparticles showed prolonged reactivity.•100% Cr(VI) removal efficiency was progressively achieved over 80 operating cycles.•Total iron concentration confirmed the enhanced mobility of encapsulated particles.•Encapsulated particles maintained full Cr(VI) removal for 30 post-injection cycles.•Collected boreholes confirmed the improved mobility of the encapsulated particles.