Hydrophobic-modified montmorillonite coating onto crosslinked chitosan as the core-shell micro-sorbent for iodide adsorptive removal via Pickering emulsion polymerization.

The radioactive iodine from nuclear wastes caused severe environmental contamination and public health concern. Chitosan and montmorillonite as green materials of the favorable adsorptivity were proposed for iodine treatment. Rather than intercalation, the crosslinked chitosan proposedly via Pickering emulsion polymerization was coated by hydrophobical-modified montmorillonite (HMMT) to form the micro-composite of chitosan/HMMT (CTS/HMMT) as the iodide adsorbent of eco-safety, adsorptivity combination and chitosan-swelling limitation. From pH 3 to 10, CTS/HMMTs adsorbed I anions no <90% during 40 min, with the maximum adsorption capacity of 0.3033 mmol/g, well-fitting with Langmuir isotherm model and the pseudo first-order kinetic model. CTS/HMMTs were also well-regenerated within the five adsorption/desorption cycles of the nearly same adsorption efficiency, performing the high stability. Nonetheless, the CTS/HMMT adsorbents were prospective for radioactive iodine removal.