Fe₃O₄@MIL‐101 – A Selective and Regenerable Adsorbent for the Removal of As Species from Water

Abstract

The chromium‐based metal–organic framework MIL‐101(Cr) served as a host for the in situ synthesis of Fe 3 O 4 nanoparticles. This hybrid nanomaterial was tested as an adsorbent for arsenite and arsenate species in groundwater and surface water and showed excellent affinity towards As III and As V species. The adsorption capacities of 121.5 and 80.0 mg g –1 for arsenite and arsenate species, respectively, are unprecedented. The presence of Ca 2+ , Mg 2+ , and phosphate ions and natural organic matter does not affect the removal efficiency or the selectivity. The structural integrity of the hybrid nanomaterial was maintained during the adsorption process and even after desorption through phosphate elution. Additionally, no significant leaching of Cr or Fe species was observed.