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

全氟烷基物质(全氟烷基和多氟烷基物质)是一组被广泛使用了几十年的人造化学品。全氟辛烷磺酸含有大量的碳氟键，这使它们非常稳定。这种稳定性使它们被称为“永远的化学物质”。全氟辛烷磺酸的广泛使用导致了广泛的土壤和水污染。这一发现非常令人担忧，因为接触全氟辛烷磺酸与严重的健康影响有关，如癌症和出生缺陷。这一问题的紧迫性变得更加紧迫，因为全氟化肥对大多数传统的化学和生物水处理过程具有抵抗力。在水中销毁全氟辛烷磺酸的一项新技术是高级还原工艺(ARPS)。Arps在水中产生电子，可以与PFAS反应，降解像PFAS这样的卤化化合物。该项目的目标是确定ARPS修复全氟辛烷磺酸污染水的潜力。这一目标将通过以下研究来实现：i)确定电子基全氟辛烷磺酸销毁过程中发生的重要反应，以及ii)开发用于预测全氟辛烷磺酸在ARP系统中降解的定量工具。这项研究的成功完成有望开发有效处理全氟辛烷磺酸污染水的新技术。通过参与和培训研究生和本科生的研究工作，以及在暑期培训计划期间培训高中STEM教师，增加国家STEM劳动力带来的其他社会好处。水合电子是已知最强的还原剂之一。最近的研究表明，水合电子能够将全氟辛烷磺酸和全氟辛烷磺酸中的氟原子还原为无毒的氟化物。然而，阻碍水合电子应用于全氟辛烷磺酸销毁的一个重要障碍是缺乏对现实世界水域中水合电子过程的定量知识。该项目的目标是开发必要的量化数据和工具，通过解决水合电子基全氟烷烃降解的潜在机理限制，评估基于紫外线的高级还原过程(UV-ARP)的全部潜力。这一总体目标将通过重点关注三个相辅相成的目标来实现：i)表征母体全氟化铝的水合电子破坏效率和绝对氟化物产量，ii)开发预测真实水域中UV-Arps降解率所需的定量方法，以及iii)使用这些定量工具开发“最佳情况”UV-ARP处理方法，并将该优化系统与其他全氟化铝降解技术进行比较。这些目标将使用最先进的时间分辨和稳态辐解，结合实验室规模的UV-ARP实验和动力学模型来实现。这项研究将通过高中STEM教师培训计划和在主要是本科院校的本科生研究人员参与，与教育和外展相结合。通过与奥兰治县水区的合作，分享水处理从业者的研究结果和建议，对社会产生了其他好处。奥兰治县水区是美国最大的全面高级水处理设施之一。这项研究的成功完成将推进ARP在真实世界水中处理PFAS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。

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.