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)已经被制造出来，并广泛应用于数百种消费品和工业过程中。向环境中排放全氟辛烷磺酸已导致数百万美国居民的饮用水供应受到超过美国环境保护局健康咨询限制的污染。不幸的是，由于这些化合物独特的分子性质，传统的水处理工艺在去除或摧毁全氟辛烷磺酸方面并不有效。这造成了国家对水处理技术的迫切需求，以解决这一问题。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，该项目的重点是开发“诱捕和摧毁”技术。这项技术利用一种新型的吸附材料来有效地从水中捕获全氟辛烷磺酸，然后利用定向紫外光和阳光辅助反应进行降解。这项研究的成功完成将通过生产有效的PFAS处理技术而造福社会。通过提高公众对全氟辛烷磺酸污染的认识来提高科学素养，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来增加全国STEM工作人员的多样性，还可以带来额外的好处。该项目的主要研究目标是开发并充分表征一种创新技术，以经济高效地从受污染的水中去除和降解全氟辛烷磺酸。这项技术是基于一种新型的吸附型光催化剂，它可以选择性地将水中的PFAS吸附到光活性固体表面，然后在紫外光或太阳光下原位破坏PFAS。该项目将针对传统的全氟化铝及其较新的替代品，如GenX。研究目标将通过一系列相互关联的研究任务来实现：i)开发优化用于处理各种PFAS的吸附型光催化剂，ii)表征用于PFAS处理的吸附型光催化剂的速度、选择性和容量，iii)表征预吸附PFAS的紫外光和太阳光固相光催化，以及iv)探索通过使用低成本氧化剂和控制反应条件来提高光催化性能的方法。通过使用材料的最先进的显微和光谱分析、反应产物的高分辨率光谱分析和现代密度泛函理论计算，将通过研究的所有阶段来研究潜在的反应机理。将进行初步成本分析，以评估该技术与替代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，能够以符合成本效益的方式处理大量受污染水中的低浓度全氟辛烷磺酸。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混合相和多个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，并潜在地转变我们在碳改性多相光催化剂的制造和应用方面的知识。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 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.