Collaborative Research: ERASE-PFAS: A "concentrate-and-destroy" technology for treating per- and polyfluoroalkyl substances using a new class of adsorptive photocatalysts

几十年来，全氟和多氟烷基物质（PFAS）已被制造并广泛应用于数百种消费品和工业过程中。向环境中释放PFAS导致数百万美国居民的饮用水供应受到污染，其程度超过了美国环境保护局的健康咨询限制。不幸的是，由于这些化合物独特的分子特性，传统的水处理工艺不能有效地去除或破坏PFAS。这使得国家迫切需要水处理技术来解决这个问题。这项研究的目标是通过一个多阶段的研究项目来解决这个问题，重点是发展“陷阱和破坏”技术。该技术利用一种新型吸附材料，从水中有效地捕获全氟辛烷磺酸，然后利用针对性的紫外线和阳光辅助反应进行降解。本研究的成功完成将通过生产有效的PFAS处理技术造福社会。通过提高公众对PFAS污染的认识，提高科学素养，以及通过让来自代表性不足群体的K-12、本科生和研究生参与研究和培训，增加美国STEM劳动力的多样性，这些都带来了额外的好处。该项目的总体研究目标是开发并充分表征一种创新技术，以经济有效地从受污染的水中去除和降解PFAS。该技术是基于一种新型的吸附光催化剂，它可以选择性地将PFAS从水中吸附到光活性固体表面，然后在紫外线或太阳光下原位破坏PFAS。该项目将针对传统PFAS及其新替代品（如GenX）。研究目标将通过一系列相互关联的研究任务来完成：1)开发针对多种PFAS进行优化处理的吸附光催化剂；2)表征PFAS处理的吸附光催化剂的速度、选择性和容量；3)表征预吸附PFAS的紫外和太阳光固相光催化作用；4)探索通过低成本氧化剂的修饰和控制反应条件来增强光催化作用的方法。潜在的反应机制将通过研究的所有阶段进行调查，使用最先进的材料微观和光谱分析，反应产物的高分辨率光谱分析和现代密度泛函理论计算。将进行初步成本分析，以评估该技术与其他治疗方案相比的成本效益。该项目的成功完成可能会带来一种创新技术，可以经济有效地处理大量污染水中低浓度的PFAS。更广泛地说，从这个项目中获得的知识也将促进我们对纳米级杂化相和多次氧化还原循环对反应性复合材料整体性能的协同效应的理解，并有可能改变我们对碳改性多相光催化剂的制造和应用的认识。该奖项反映了美国国家科学基金会的法定使命，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。

Per- and polyfluoroalkyl substances (PFAS) have been manufactured and widely used in hundreds of consumer products and industrial processes for decades. Release of PFAS into the environment has resulted in drinking water supplies for millions of U.S. residents to become contaminated at levels exceeding United States Environmental Protection Agency health advisory limits. Unfortunately, conventional water treatment processes are not effective at removing or destroying PFAS due to the unique molecular properties of these compounds. This has created an urgent national need for water treatment technology to address this problem. The goal of this research is to address this problem through a multi-phase research project focused on developing “trap and destroy” technology. This technology utilizes a new class of adsorptive materials to efficiently capture PFASs from water, followed by degradation using targeted ultraviolet and sunlight-assisted reaction. Successful completion of this research will benefit society through the production of effective PFAS treatment technology. Additional benefits result from increased scientific literacy through enhanced public awareness of PFAS contamination, as well as by increasing the diversity of the Nation’s STEM workforce by engagement of K-12, undergraduate, and graduate students from underrepresented groups in research and training.The overarching research goal of this project is to develop and fully characterize an innovative technology to cost-effectively remove and degrade PFAS from contaminated water. The technology is based on a new class of adsorptive photocatalysts that can selectively adsorb PFAS from water to the photoactive solid surface, and then destroy PFAS in situ under UV or solar light. This project will target both legacy PFAS and their newer substitutes such as GenX. The research goals will be accomplished through a series of interconnected research tasks to: i) develop adsorptive photocatalysts optimized for treatment of a wide range of PFAS, ii) characterize the speed, selectivity, and capacity of the adsorptive photocatalysts for PFAS treatment, iii) characterize UV- and solar-light solid-phase photocatalysis of the pre-adsorbed PFAS, and iv) explore ways to enhance photocatalysis through amendment with low-cost oxidants and manipulation of reaction conditions. The underlying reaction mechanisms will be investigated through all stages of the research using state-of-the-science microscopic and spectroscopic analyses of the materials, high-resolution spectroscopic analysis of the reaction products, and modern density functional theory calculations. A preliminary cost analysis will be carried out to assess the cost-effectiveness of the technology compared to alternative treatment options. Successful completion of the project will potentially lead to an innovative technology that can cost-effectively treat low concentrations of PFAS in large volumes of contaminated water. More broadly, the knowledge gained from this project will also advance our understanding of the synergistic effects of nanoscale hybrid phases and multiple redox cycles on the overall performance of reactive composite materials, and potentially transform our knowledge on fabrication and application of carbon-modified, multi-phase photocatalysts.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.