Magnetic chitosan nanoparticles for removal of Cr(VI) from aqueous solution

► Magnetic chitosan nanoparticles were synthesized. ► They possess maximum adsorption capacity of 64.31 mg·g− 1 for Cr(VI). ► The adsorption was pH-dependent and its kinetics follows the pseudo-second-order. ► The nanoparticles can serve as a promising adsorbent for Cr(VI) and other ions.