Adsorption, Structure, and Dynamics of Short- and Long-Chain PFAS Molecules in Kaolinite: Molecular-Level Insights
Adsorption, Structure, and Dynamics of Short- and Long-Chain PFAS Molecules in Kaolinite: Molecular-Level Insights
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DOI：
10.1021/acs.est.2c01054
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发表时间：
2022-06-21
影响因子：
11.4
通讯作者：
Wilson, Angela K.
中科院分区：
文献类型：
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作者：
Loganathan, Narasimhan;Wilson, Angela K.
多氟烷基和全氟烷基物质（PFAS）在不同的自然环境中普遍存在，对环境和人类健康构成严重威胁。土壤和沉积物是人类和动物接触PFAS的重要途径之一。随着PFAS在土壤中生物累积性和流动性的增加，了解PFAS分子与土壤中主要成分（如粘土矿物）的相互作用至关重要。本研究报告的第一次基本的分子水平的见解的吸附，界面结构，和动力学的短链和长链PFAS分子在水饱和的高岭石粘土中孔使用经典的分子动力学（MD）模拟。在环境条件下，所有的PFAS分子都只吸附在高岭石的羟基表面附近，与末端官能团和金属阳离子无关。PFAS的界面吸附结构和配位环境强烈依赖于功能基团的性质和它们的疏水链长度。长链PFAS在高岭石的羟基表面上形成大的聚集簇是其与短链PFAS分子相比的受限动力学的原因。这种全面的知识PFAS在粘土矿物界面是至关重要的，以开发新的网站特定的降解和缓解策略。
The ubiquitous presence of poly- and perfluoroalkyl substances (PFAS) in different natural settings poses a serious threat to environmental and human health. Soils and sediments represent one of the important exposure pathways of PFAS for humans and animals. With increasing bioaccumulation and mobility, it is extremely important to understand the interactions of PFAS molecules with the dominant constituents of soils such as clay minerals. This study reports for the first time the fundamental molecular-level insights into the adsorption, interfacial structure, and dynamics of short- and long-chain PFAS molecules at the water-saturated mesopores of kaolinite clay using classical molecular dynamics (MD) simulations. At environmental conditions, all the PFAS molecules are exclusively adsorbed near the hydroxyl surface of the kaolinite, irrespective of the terminal functional groups and metal cations. The interfacial adsorption structures and coordination environments of PFAS are strongly dependent on the nature of the functional groups and their hydrophobic chain length. The formation of large, aggregated clusters of long-chain PFAS at the hydroxyl surface of kaolinite is responsible for their restricted dynamics in comparison to short-chain PFAS molecules. Such comprehensive knowledge of PFAS at the clay mineral interface is critical to developing novel site-specific degradation and mitigation strategies.