The influence of molecular structure on the adsorption of PFAS to fluid-fluid interfaces: Using QSPR to predict interfacial adsorption coefficients
The influence of molecular structure on the adsorption of PFAS to fluid-fluid interfaces: Using QSPR to predict interfacial adsorption coefficients
复制标题
DOI：
10.1016/j.watres.2018.12.057
复制
发表时间：
2019-04-01
期刊：
影响因子：
12.8
通讯作者：
Brusseau, Mark L.
中科院分区：
文献类型：
--
作者：
Brusseau, Mark L.
全氟烷基物质和多氟烷基物质(PFAS)是人类健康风险严重关注的新污染物。评估暴露风险需要对全氟辛烷磺酸在环境中的迁移和去向行为有透彻的了解。吸附到流体-流体界面，包括空气-水、油-水和气-油界面(其中油代表有机不相容的液体)，是PFAS传输的一个潜在的重要保留过程。流体-液体界面吸附系数(K-I)是运输模拟和风险描述所必需的，但目前绝大多数全氟辛烷磺酸尚不具备这些数据。使用从文献中收集的表面张力和界面张力数据集来确定42个PFA的界面吸附系数。评估的全氟烷烃包括全氟羧酸盐和全氟磺酸盐的同系物系列、支化的全氟烷基、多氟烷基、醇类全氟烷和非离子全氟烷。K-I值在八个数量级之间变化，并且是分子结构的函数。定量结构/性质关系(QSPR)分析的结果表明，以摩尔体积(V-m)作为描述符的模型能够很好地预测宽范围PFAS的气水界面吸附的logKI值。该模型还对一组有限的油水界面吸附数据进行了很好的预测。QSPR模型对结构变化范围较大的PFAS的预测能力反映了摩尔体积合理地描述了分子大小对溶液中空穴形成/破坏的影响，从而反映了界面吸附的疏水相互作用驱动力。本文提出的QSPR模型提供了一种将液-液界面吸附过程结合到环境中全氟辛烷磺酸的传输特性和风险评估中的方法。这对于确定大气、包气带、含有有机不混溶液体的源区以及水/废水处理系统中的全氟辛烷磺酸质量通量特别重要。(C)2019爱思唯尔有限公司。保留所有权利。
Per- and poly-fluoroalkyl substances (PFAS) are emerging contaminants of critical concern for human health risk. Assessing exposure risk requires a thorough understanding of the transport and fate behavior of PFAS in the environment. Adsorption to fluid-fluid interfaces, which include air-water, OIL-water, and air-OIL interfaces (where OIL represents organic immiscible liquid), is a potentially significant retention process for PFAS transport. Fluid-fluid interfacial adsorption coefficients (K-i) are required for use in transport modeling and risk characterization, yet these data are currently not available for the vast majority of PFAS. Surface-tension and interfacial-tension data sets collected from the literature were used to determine interfacial adsorption coefficients for 42 individual PFAS. The PFAS evaluated comprise homologous series of perfluorocarboxylates and perfluorosulfonates, branched perfluoroalkyls, polyfluoroalkyls, alcohol PFAS, and nonionic PFAS. The K-i values vary across eight orders of magnitude, and are a function of molecular structure. The results of quantitative-structure/property-relationship (QSPR) analysis demonstrate that a model employing molar volume (V-m) as a descriptor provides robust predictions of log Ki values for air-water interfacial adsorption of the wide range of PFAS. The model also produced good predictions for a limited set of data for OIL-water interfacial adsorption. The predictive capability of the QSPR model for a wide range of PFAS with greatly varying structures reflects the fact that molar volume provides a reasonable representation of the influence of molecular size on cavity formation/destruction in solution, and thus the hydrophobic-interaction driving force for interfacial adsorption. The QSPR model presented herein provides a means to incorporate the fluid-fluid interfacial adsorption process into transport characterization and risk assessment of PFAS in the environment. This will be particularly relevant for determining PFAS mass flux in the atmosphere, in the vadose zone, in source zones containing organic immiscible liquids, and in water/wastewater treatment systems. (C) 2019 Elsevier Ltd. All rights reserved.