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

全氟和多氟烷基化合物(PFAS)是一类广泛分布于环境中的合成化合物。最近的证据表明，全氟辛烷磺酸可导致对人类不利的健康后果。这些化合物越来越多地出现在饮用水和土壤中。这些事态发展导致了许多关于其使用的法律和监管行动。尽管在过去的几十年里进行了大量的研究，但我们对全氟辛烷磺酸在环境中的持久性的认识仍然存在重大差距。该项目旨在通过在超级计算机上进行分子动力学模拟，深入了解全氟辛烷磺酸和其他有机污染物在固体表面的分子尺度吸附。关于全氟辛烷磺酸对固体表面亲和力的概括性知识有可能改变我们对这些化合物环境命运的理解。这项研究的成功完成将导致建立更好的PFAS环境可持续性模型，并有可能开发新的水处理和土壤修复技术，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和更广泛的教育界产生结果的可视化，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的蒙皂石粘土表面的吸附。研究的重点是极性或阴离子有机污染物，包括许多新出现的令人关注的化合物，如全氟烷基物质和多氟烷基物质(PFAS)。与多氯联苯或多环芳烃等遗留污染物相比，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。鉴于这些化合物对现场修复和水处理构成的严峻挑战，对全氟化肥的关注是及时和相关的。这项研究将开发一种新的计算化学方法，可以在分子水平上准确预测极性或阴离子有机污染物对原始蒙皂石粘土表面和有机涂层蒙脱石粘土表面的亲和力。变量包括对不同范围的53种化合物的化合物结构吸附的影响、水化学和有机粘土表面涂层。这一方法将通过实验室吸附实验进行验证，以开发新的地球化学模拟工具。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中的模拟结果。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.