Clay mineral adsorption affinity for heavy metals: Experimental results and atomic-scale insights; Applied Surface Science; Vol. 750
| Parent link: | Applied Surface Science.— .— Amsterdam: Elsevier Science Publishing Company Inc. Vol. 750.— 2026.— Article number 167935, 44 p. |
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| Other Authors: | , , , , , , , , , |
| Summary: | Title screen Clay minerals can serve as low-cost materials to remove heavy metals, yet how crystallochemical properties of clays govern their metal removal performance remains poorly understood. This study investigated Pb2+, Cd2+, and Hg2+ adsorption on montmorillonite (Mnt), illite (Ilt), kaolinite (Kln), and chlorite (Chl) at pH 7.0 using batch experiments and molecular dynamics (MD) simulations. Kinetic results revealed a metal removal order of Pb2+> Cd2+> Hg2+ for Mnt, Ilt, and Kln, while Chl showed Pb2+> Hg2+> Cd2+. Adsorption kinetic data fitted the pseudo-second-order model, indicating surface reaction limitation. All clays exhibited strong Pb2+ adsorption; Chl displayed specific Hg2+ affinity. MD simulation results showed that the source of layer charge determines interfacial binding forms. Octahedral substitution in Mnt generates extensive electrostatic fields for Pb2+ outer-sphere complexation, while tetrahedral charge in Ilt and Chl creates localized electric fields to trigger partial cation dehydration and inner-sphere coordination of Cd2+ and Hg2+. Hg2+ binding in Chl stems from favorable Hg2+-siloxane surface interactions. Basal surface properties primarily govern overall metal uptake trends despite edge surfaces contributing to low-concentration metal retention. This work provides guidance for clay sorbent screening and clarifies the microstructure-adsorption relationship at the atomic level Текстовый файл AM_Agreement |
| Language: | English |
| Published: |
2026
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| Subjects: | |
| Online Access: | https://doi.org/10.1016/j.apsusc.2026.167935 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=688480 |
| Summary: | Title screen Clay minerals can serve as low-cost materials to remove heavy metals, yet how crystallochemical properties of clays govern their metal removal performance remains poorly understood. This study investigated Pb2+, Cd2+, and Hg2+ adsorption on montmorillonite (Mnt), illite (Ilt), kaolinite (Kln), and chlorite (Chl) at pH 7.0 using batch experiments and molecular dynamics (MD) simulations. Kinetic results revealed a metal removal order of Pb2+> Cd2+> Hg2+ for Mnt, Ilt, and Kln, while Chl showed Pb2+> Hg2+> Cd2+. Adsorption kinetic data fitted the pseudo-second-order model, indicating surface reaction limitation. All clays exhibited strong Pb2+ adsorption; Chl displayed specific Hg2+ affinity. MD simulation results showed that the source of layer charge determines interfacial binding forms. Octahedral substitution in Mnt generates extensive electrostatic fields for Pb2+ outer-sphere complexation, while tetrahedral charge in Ilt and Chl creates localized electric fields to trigger partial cation dehydration and inner-sphere coordination of Cd2+ and Hg2+. Hg2+ binding in Chl stems from favorable Hg2+-siloxane surface interactions. Basal surface properties primarily govern overall metal uptake trends despite edge surfaces contributing to low-concentration metal retention. This work provides guidance for clay sorbent screening and clarifies the microstructure-adsorption relationship at the atomic level Текстовый файл AM_Agreement |
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| DOI: | 10.1016/j.apsusc.2026.167935 |