Cr(VI) retention and transport through Fe(III)-coated natural zeolite

► Zeolite modified with Fe(III) could be used for adsorption and retention of Cr(VI). ► The Fe present on zeolite was in an amorphous Fe(OH)3 form. ► A Cr(VI) adsorption capacity of 82 mg/kg was found on Fe(III)-zeolite. ► A Cr(VI) retardation factor of 3 or 5 was determined from column and batch studies.