Immobilization of iodide (I-) from groundwater and soils is a challenging subject due to the large size and low charge of I-. Clay minerals and (hydr)oxides generally exhibit very low adsorption capacity due to anion exclusion or weak attraction. For the first time, the adsorption of I- by chrysotile bundles (Chry-B) was investigated and a characteristic mechanism was established by comparing the adsorption of I- on Chry-B with dispersed chrysotile single nanotubes, lizardite and brucite. The adsorption of I- by Chry-B reached equilibrium with 24 h, and Chry-B exhibited very strong adsorption to I-, with a distribution coefficient (K-d) of 179.24 mL/g, which is two orders of magnitude higher than those for previously reported clay minerals. The Langmuir adsorption capacity of Chry-B was 4.13 mg/g. The wedge-shaped nanopores among the neighboring nanotubes in Chry-B proved to be the primary adsorption sites for I-. The I- at end of the wedge sites was strongly bonded by the nanopores due to the severe superposition of electric potentials from the charged walls of the narrowing wedges. These results demonstrated that chrysotile bundles were a promising candidate for adsorption of I-, and that the shape of nanopore geometry was crucial in I- adsorption. Publication name | APPLIED CLAY SCIENCE Volume: 183 Article Number: 105331 DOI: 10.1016/j.clay.2019.105331 Published: DEC 15 2019 | Author(s) | Yu, Wenbin; Xu, Huifang; Roden, Eric E.; Wan, Quan | Corresponding author(s) | XU Huifang hfxu@geology.wisc.edu Univ Wisconsin, Dept Geosci, 1215 West Dayton St,A352 Weeks Hall, Madison, WI 53706 USA. | Author(s) from IGCAS | YU Wenbin; WAN Quan | View here for the details
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