Collaborative Research: Towards a Better Understanding of the Atmospheric Fate of PFAS

全氟和多氟烷基物质(PFAS)作为一种化学和热稳定的化合物，已被用于许多工业应用(如不粘涂料)。然而，这些化合物已知对人类健康的影响，因此基本上已被逐步淘汰。尽管如此，空气和水中仍然检测到全氟辛烷磺酸化合物，我们对全氟辛烷磺酸化合物的化学降解和环境命运的理解存在数据差距。这项工作将进行实验室实验，以填补这一数据空白，并提高对全氟辛酸(PFOA)化学以及全氟辛酸化合物对环境和人类健康可能影响的理解。这项拟议的工作有三个主要研究目标：(1)量化与全氟辛酸和全氟辛酸替代化学品大气相分配相关的热力学性质；(2)估计这些化学品相对于OH化学的大气寿命；以及(3)研究这些化学品的反应机理。此外，这项拟议的工作有一个教育目标，即建立一个交流，使本科生能够通过在合作机构之间开展暑期研究来扩大他们的教育经验。这项拟议工作将开展三项主要任务，以实现这些目标。首先，该团队将量化影响全氟辛烷磺酸相分配的热力学性质--即饱和蒸汽压、亨利挥发度和酸离解常数。其次，他们将进行多个氧化流动反应器实验，以限制OH自由基化学对PFAS的影响。第三，他们将估计全氟辛烷磺酸相对于羟基的速率常数，并开发潜在的反应机制。该项目支持一名博士后研究人员。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 Poly-fluorinated alkyl substances (PFAS), have been used in many industrial applications (e.g., non-stick coating) as a chemically and thermally stable compound. However, these compounds have known human health impacts, and thus have been largely phased out. Nonetheless, PFAS compounds are still detected in air and water, and there exists a data gap in our understanding of the chemical degradation and environmental fate of PFAS compounds. This work will perform laboratory experiments in order to fill this data gap and improve out understanding of PFAS chemistry – with a focus on perfluorooctanoic acid (PFOA) – and the likely impact of PFAS compounds on the environment and human health.This proposed work has three primary research goals: (1) to quantify the thermodynamic properties relevant for atmospheric phase partitioning of PFAS and PFAS-replacing chemicals; (2) to estimate the atmospheric lifetime of these chemicals against OH chemistry; and (3) to investigate reaction mechanisms of these chemicals. Additionally, this proposed work has an educational objective to establish an exchange to enable undergraduate students to broaden their educational experience by conducting summer research among the collaborative institutions. This proposed work will conduct three primary tasks to reach these objectives. First, the team will quantify the thermodynamic properties – namely saturation vapor pressure, Henry volatility, and acid dissociation constants – that influence the phase partitioning of PFAS. Second, they will conduct multiple oxidation flow reactor experiments to constrain the impact of OH radical chemistry on PFAS. Third, they will estimate rate constants of PFAS against OH and develop potential reaction mechanisms.This project supports one postdoctoral researcher.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.