CAS: Elucidating Mechanisms of Perfluoroalkyl Substances Degradation in the Environment: A Coupled Computational Experimental Approach

在NSF化学部环境化学科学（ECS）计划的支持下，Shabham Vyas和他在科罗拉多矿业学院的学生将研究环境中全氟烷基和多氟烷基物质（PFAS）的反应性。该项目的重点是PFAS与各种活性物质（如碳酸根）的化学反应，以及金属离子在此过程中的作用。PFAS是最持久的人为化学品之一，悄悄地在世界各地扩散。PFAS的独特性质，特别是其化学稳定性，使其具有多种应用。然而，过去二十年的研究指出PFAS对环境和生物系统的潜在不利影响。该项目将使用先进的计算机建模和有针对性的实验来进行，其总体目标是建立实现完全分解此类环境污染物的方法。该项目将为研究生和本科生提供参与跨学科研究的机会。Vyas博士还将参加K-12外展计划，以鼓励学生在STEM（科学，技术，工程和数学）领域从事职业。动力学和热力学参数的各种化学转化，包括电子转移反应，将获得使用密度泛函理论和后Hartree-Fock为基础的化学计算。与此同时，将利用激光闪光光解、随时间变化的光解、电子顺磁共振和质谱等技术进行有针对性的实验。本工作的第一个目标是定量测量PFAS与自由基物种的反应性和相关的电子转移反应的探针机制。第二个目标是研究环境相关的过渡金属离子在PFAS自由基介导的降解中的作用。本项目的第三个目标是描述PFAS的降解机制以及自由基和金属离子的影响。总的来说，这项研究工作将定量地建立PFAS的反应性和它们与环境中可用的反应性物种的降解。最终目标是建立基础科学，有一天可能导致PFAS的完全矿化。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With support from the Environmental Chemical Sciences (ECS) Program in the Division of Chemistry at NSF, Shabham Vyas and his students at the Colorado School of Mines will study the reactivity of per- and polyfluoroalkyl substances (PFAS) in the environment. The project focuses on chemical reactions of PFAS with various reactive species, such as carbonate radicals, and the role metal ions play in this process. PFAS are among the most persistent anthropogenic chemicals that quietly proliferated throughout the world. The unique properties of PFAS, especially their chemical stability, lent them to diverse applications. However, research in the last two decades points to potential adverse effects of PFAS on the environment and in biological systems. This project will be carried out using cutting edge computer modeling and targeted experimentation with the overall objective of establishing methods to achieve complete breakdown of such environmental contaminants. This project will provide graduate and undergraduate students opportunities to participate in interdisciplinary research. Dr. Vyas also will participate in K-12 outreach programs to encourage students to pursue careers in STEM (science, technology, engineering and mathematics) fields. Kinetic and thermodynamic parameters for various chemical transformations, including electron transfer reactions, will be obtained using density functional theory and post-Hartree-Fock-based chemical computations. Concurrently, targeted experiments will be performed using techniques such as laser flash photolysis, time-dependent photolysis, electron paramagnetic resonance and mass spectrometry. The first objective of this work is to quantitatively measure the reactivity of PFAS with radical species and probe mechanisms of associated electron transfer reactions. The second objective will be to investigate the role of environmentally relevant transition metal ions in radical-mediated degradation of PFAS. The third objective of this project is to delineate the degradation mechanisms of PFAS and the impact of radicals and metal ions. Collectively, this research work will quantitatively establish the reactivity of PFAS and their degradation with the available reactive species in the environment. The ultimate goal would be to establish fundamental science that might one day lead to complete mineralization of PFAS.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.