ERASE-PFAS: Collaborative Research: Development of Quantitative Tools to Assess the Mechanisms and Full Potential of UV-ARPs for the Treatment of PFASs in Water

PFAS（全氟烷基和多氟烷基物质）是一组已广泛使用数十年的人造化学品。PFAS含有大量的碳氟键，使其非常稳定。这种稳定性使它们被称为“永久化学品”。PFAS的广泛使用导致了土壤和水的广泛污染。这一发现引起了极大的关注，因为PFAS暴露与严重的健康影响有关，如癌症和出生缺陷。由于PFAS对大多数传统的化学和生物水处理工艺具有抗性，因此该问题的紧迫性更大。一种新技术，已显示出对PFAS在水中的破坏的承诺是先进的还原过程（ARP）。ARP在水中产生电子，可以与PFAS反应降解PFAS等卤代化合物。本项目的目标是确定ARPs修复PFAS污染水的潜力。这一目标将通过以下研究来实现：i）确定基于电子的PFAS销毁过程中发生的重要反应，ii）开发用于预测阿普系统中PFAS降解的定量工具。这项研究的成功完成有望开发新技术，有效地处理PFAS污染的水。通过对研究生和本科生的参与和培训，以及在暑期培训项目中对高中STEM教师的培训，增加了国家的STEM劳动力，从而为社会带来了额外的好处。水合电子是已知的最强还原剂之一。最近的研究表明，水合电子能够将PFAS（包括PFOA和PFOS）中的氟原子还原为无毒的氟化物。然而，一个重要的障碍，防止应用的PFAS破坏的水合电子是缺乏定量的知识，在现实世界的沃茨中的水合电子为基础的过程。该项目的目标是通过解决水合电子基PFAS降解的潜在机制限制，开发必要的定量数据和工具，以评估基于紫外线的高级还原过程（UV-ARP）的全部潜力。为实现这一总体目标，将侧重于以下三个相辅相成的目标：i）表征母体PFAS基于水合电子的破坏效率和绝对氟化物产率，ii）开发预测UV-ARP在真实世界沃茨中PFAS降解速率所需的定量方法，和iii）使用这些定量工具来开发“最佳情况”UV-ARP处理，并将该优化系统与其它PFAS降解技术进行比较。这些目标将使用国家的科学时间分辨和稳态辐解，结合实验室规模的UV-ARP实验和动力学建模来实现。该研究将通过高中STEM教师培训计划以及主要本科院校本科研究人员的参与与教育和外展相结合。通过与全国最大的全面先进水处理设施之一的橙子县水务区合作，为水处理从业者分享研究成果和建议，为社会带来了额外的好处。这项研究的成功完成将推动ARPs在实际沃茨中用于PFAS处理的基础科学和工程潜力。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审查标准进行评估，被认为值得支持。

PFAS (per- and polyfluoroalkyl substances) are a group of man-made chemicals that have been widely used for many decades. PFAS contain numerous carbon-fluorine bonds that makes them extremely stable. This stability has led to them being called “forever chemicals.” The broad use of PFAS has resulted in widespread contamination of soil and water. This finding is of great concern, as PFAS exposure have been linked to serious health effects, such as cancer and birth defects. The urgency of this problem is made greater because PFAS are resistant to most conventional chemical and biological water treatment processes. One new technology that has shown promise for PFAS destruction in water is Advanced Reduction Processes (ARPs). ARPs produce electrons in water, which can react with PFAS to degrade halogenated compounds like PFAS. The goal of this project is to determine the potential of ARPs for remediating PFAS contaminated water. This goal will be achieved through research to: i) identify the important reactions occurring in the electron-based PFAS destruction process, and ii) develop quantitative tools for predicting PFAS degradation in ARP systems. Successful completion of this research holds promise to develop new technology to effectively treat PFAS contaminated water. Additional benefits to society result from increasing the Nation’s STEM workforce through the engagement and training of graduate and undergraduate students in research, as well as training of high school STEM teachers during summer training programs.Hydrated electrons are one of the strongest known reductants. Recent studies show that the hydrated electron is capable of reducing fluorine atoms in PFAS, including PFOA and PFOS, to non-toxic fluoride. However, a significant barrier preventing application of hydrated electrons for PFAS destruction is the lack of quantitative knowledge of hydrated electron-based processes in real-world waters. The goal of this project is to develop the quantitative data and tools necessary to assess the full potential of Ultraviolet-based Advanced Reduction Processes (UV-ARP) by addressing the underlying mechanistic limitations of hydrated electron-based PFAS degradation. This overall goal will be realized by focusing on three complementary objectives to: i) characterize the hydrated electron-based destruction efficiencies of parent PFAS and absolute fluoride yields, ii) develop the quantitative methods needed to predict PFAS degradation rates by UV-ARPs in real-world waters, and iii) use these quantitative tools to develop a “best case” UV-ARP treatment and compare this optimized system to other PFAS degradation technologies. These objectives will be accomplished using state-of-the-science time-resolved and steady-state radiolysis, combined with bench-scale UV-ARP experiments and kinetic modeling. The research will be integrated with education and outreach through high school STEM teacher training programs and engagement of undergraduate researchers at a primarily undergraduate institution. Additional benefits to society result from the sharing of research findings and recommendations for water treatment practitioners through partnership with the Orange County Water District, one of the largest full-scale advanced water treatment facilities in the Nation. Successful completion of this research will advance the fundamental science and engineering potential of ARPs for PFAS treatment in real-world waters.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.