Influence of Soil Minerals on the Adsorption, Structure, and Dynamics of GenX
Influence of Soil Minerals on the Adsorption, Structure, and Dynamics of GenX
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DOI：
10.1021/acsestwater.3c00171
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发表时间：
2023-07
期刊：
影响因子：
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通讯作者：
Christina E. Schumm;Narasimhan Loganathan;A. Wilson
中科院分区：
文献类型：
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作者：
Christina E. Schumm;Narasimhan Loganathan;A. Wilson
近年来，世界各地采取了越来越多的主动行动，采用替代的全氟烷基物质(PFAS)分子和多氟烷基物质(PFAS)分子，以最大限度地减少与传统PFAS分子相关的环境和健康影响。六氟环氧丙烷二聚酸(HFPO-DA)，俗称GenX，是目前用于全氟辛酸的重要替代品之一。然而，越来越多的研究表明，GenX在自然环境中被发现，包括土壤和地下水，因此强调了了解它们在这些环境中的吸附行为的必要性。本研究首次从分子水平深入研究了粘土矿物这三种不同的常见土壤成分在决定GenX在基本分子水平上的吸附和传输特性方面的不同矿物组成和表面电荷分布的影响。三种粘土矿物对GenX的表面络合作用差异很大，决定络合作用的因素也完全不同。根据粘土矿物的不同，既观察到表面吸附的GenX，也观察到溶液相的GenX。重点介绍了GenX的界面结构、近邻配位、动力学行为以及它们与矿物体系中遗留的PFAS的关系。
In recent years, there have been increasing initiatives undertaken worldwide to employ alternative per- and polyfluoroalkyl substances (PFAS) molecules in order to minimize the environmental and health effects associated with legacy PFAS molecules. Hexafluoropropylene oxide dimer acid (HFPO-DA), commonly known as GenX, is one of the important replacements currently used for PFOA. However, growing investigations suggest that GenX is identified in natural settings, including soils and groundwater, thus emphasizing the need to understand their sorption behavior in these environments. This study provides molecular-level insights into the impact of three different common soil constituents, namely, clay minerals, that vary in mineralogical composition and surface charge distribution in dictating the adsorption and transport characteristics of GenX on a fundamental molecular level for the first time using molecular dynamics simulations. The surface complexation of GenX varies significantly between the three clay minerals, and the factors that dictate the complexation are completely different. Depending upon the clay minerals, both surface-adsorbed and solution-phase GenX are observed. Importantly, the interfacial structure, nearest neighbor coordination, and dynamic behavior of GenX and their correlation with legacy PFAS in minerals systems are presented.