Adsorption of Per- and Polyfluoroalkyl Substances (PFASs) and Other Polar Organic Contaminants on Pristine and Organic-Coated Clay Mineral Surfaces

全氟烷基和多氟烷基物质（PFAS）是一类广泛分散在环境中的合成化合物。最近的证据表明，PFAS可导致人类不良健康结果。这些化合物在饮用水和土壤中的发现越来越多。这些发展导致了许多关于其使用的法律的和监管行动。尽管在过去的几十年里进行了大量的研究，但我们对PFAS的环境持久性的认识仍然存在重大差距。该项目旨在利用超级计算机上的分子动力学模拟，深入了解PFAS和其他有机污染物在固体表面的分子尺度附着。PFAS对固体表面的亲和力的普遍知识有可能改变我们对这些化合物的环境命运的理解。该研究的成功完成将导致PFAS环境持久性的更好模型，以及新型水处理和土壤修复技术的潜在发展，以保护人类和生态健康。一个基于网络的科学门户将为K-12和更广泛的教育界提供可视化的结果，从而提高国家的科学素养。该项目的目标是了解有机污染物在原始和有机涂层蒙皂石粘土表面的吸附。研究重点是极性或阴离子有机污染物，包括许多新出现的化合物，如全氟烷基和多氟烷基物质（PFAS）。这些化合物表现出更多样化的官能团和更复杂的吸附行为比传统的污染物，如多氯联苯或多环芳烃。考虑到这些化合物对场地修复和水处理构成的严峻挑战，对PFAS的关注是及时和相关的。该研究将开发一种新的计算化学方法，可以在分子尺度上准确预测极性或阴离子有机污染物对原始和有机涂层蒙皂石粘土表面的亲和力。变量包括对化合物结构的吸附的影响，为各种各样的53种化合物，水化学，和有机粘土表面涂层。该方法将使用实验室吸附实验来验证，以开发新的地球化学建模工具。该项目团队将开发一个基于网络的界面，使更广泛的高中学生和教师教育社区能够可视化和探索存储在国家能源研究科学计算中心（NERSC）高性能数据存储系统上的模拟结果。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持审查标准。

Per- and Polyfluoroalkyl Substances (PFAS) are a class of synthetic compounds that have been widely dispersed in the environment. Recent evidence indicates that PFAS can lead to adverse health outcomes in humans. These compounds are being found increasingly in drinking water and soils. These developments have led to numerous legal and regulatory actions regarding their use. Despite numerous studies over the past few decades, there remain significant gaps in our knowledge of the environmental persistence of PFAS. This project aims to gain deep insight into the molecular-scale attachment of PFAS and other organic contaminants to solid surfaces using molecular dynamics simulations on supercomputers. Generalizable knowledge of the affinity of PFAS for solid surfaces has the potential to transform our understanding of the environmental fate of these compounds. Successful completion of the research will lead to better models of environmental persistence of PFAS, and the potential development of novel water treatment and soil remediation technologies to protect human and ecological health. A web-based science gateway will produce visualizations of results for the K-12 and broader educational community, thus increasing the scientific literacy of the Nation.The goal of this project is to understand the adsorption of organic contaminants on pristine and organic-coated smectite clay surfaces. The research focuses on polar or anionic organic contaminants, including many compounds of emerging concern such as per- and polyfluoroalkyl substances (PFAS). These compounds exhibit a more diverse range of functional groups and more complex adsorption behaviors than legacy pollutants such a polychlorinated biphenyls or polycyclic aromatic hydrocarbons. The focus on PFAS is timely and relevant given the acute challenges these compounds pose for site remediation and water treatment. The research will develop a novel computational chemistry methodology that can accurately predict the affinity of polar or anionic organic contaminants for pristine and organic-coated smectite clay surfaces at the molecular scale. Variables include the influence on adsorption of compound structure for a diverse range of 53 compounds, aqueous chemistry, and organic clay surface coatings. This methodology will be validated using laboratory sorption experiments to develop new geochemical modeling tools. The project team will develop a web-based interface that will enable the broader educational community of high school students and teachers to visualize and explore simulation results stored on the high-performance data storage systems at the National Energy Research Scientific Computing Center (NERSC).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.