ERASE-PFAS: Exploring efficient pilot-scale treatment of per- and polyfluoroalkyl substances and comingled chlorinated solvents in groundwater using magnetic nanomaterials

全氟烷基和多氟烷基物质（PFAS）是自20世纪40年代以来在众多消费品和工业应用中生产和使用的含氟有机化学品。由于其持久性、稳定性和对自然环境退化过程的抵抗力，PFAS通常被称为“永远的化学物质”。此外，PFAS已被证明在人体组织和水生生物中生物积累，引起人们对其毒性和对人类和生态系统健康的不利影响的关注。在过去的二十年中，PFAS越来越多地在地下水含水层中被检测到，这些含水层是美国许多社区的饮用水来源。在受污染的地下水含水层中，PFAS通常与其他有毒化学物质（如氯化溶剂，包括三氯乙烯（TCE）和四氯乙烯（PCE））一起发现。本项目的总体目标是设计、评估和优化一种新型两相暗光反应器（DRL），用于使用磁性和光化学活性纳米材料对PFAS和氯化溶剂混合物污染的地下水进行脱地处理。该项目的成功完成将通过产生基础知识来促进开发和部署有效和可持续的技术，以处理和修复受全氟磺酸钠和氯化溶剂混合物污染的地下水含水层，从而造福社会。通过学生教育和培训，包括在卡本代尔的南伊利诺伊大学指导三名研究生，将为社会带来额外的好处。在地下水含水层和地下地层中，PFAS污染物经常与有毒化学物质混合，如氯化溶剂，包括三氯乙烯（TCE）和四氯乙烯（PCE）。然而，迄今为止，对全氟磺酸钠和氯化溶剂混合物污染的地下水含水层的处理和补救研究有限。此外，迫切需要进行中试规模的研究，以证明和验证正在进行实验规模实验室研究的有前途的PFAS地下水修复技术的可行性和现场规模的适用性。本研究的目的是开发、评估和验证一种综合吸附-光催化工艺在PFAS和TCE/PCE混合物污染地下水的脱地处理和修复中的现场规模适用性。为了实现这一目标，首席研究员（PI）和研究团队建议设计、评估和优化一种两相暗光反应器（DRL），该反应器将利用纳米材料在黑暗中吸收PFAS并部分破坏TCE/PCE，然后将纳米材料暴露在紫外线下以破坏剩余的吸收PFS和TCE/PCE污染物。该研究的具体目标是：1)利用创新和可扩展的工艺合成和表征纳米级零价铁/还原氧化石墨烯纳米杂化物；2)开展实验规模的实验室研究，评估环境因素对DLR去除污染地下水中PFAS和TCE/PCE效率的影响；3)开展现场试验研究，评估和优化新型DRL和纳米材料对PFAS和TCE/PCE混合物污染地下水的脱地处理和修复效果。为了实现该项目的教育和推广目标，PI计划利用位于卡本代尔的南伊利诺伊大学的“研究充实挑战”（REACH）计划，招募和指导本科女学生参与该项目。此外，PI计划与美国地质调查局（USGS）和伊利诺斯州环境保护局（EPA）合作，分享研究结果，并讨论在伊利诺斯州受污染地点的新型两相暗光反应堆的潜在现场应用/示范。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) are fluorinated organic chemicals that have been manufactured and used in numerous consumer products and industrial applications since the 1940s. PFAS are commonly referred to as “forever chemicals” due to their persistence, stability, and resistance to natural environmental degradation processes. In addition, PFAS have been shown to bioaccumulate in human tissues and aquatic organisms raising concerns about their toxicity and adverse impact on human and ecosystem health. During the last two decades, PFAS have been increasingly detected in groundwater aquifers which serve as sources of drinking water for many communities throughout the United States. In contaminated groundwater aquifers, PFAS are often found alongside other toxic chemicals such as chlorinated solvents including trichloroethylene (TCE) and tetrachloroethylene (PCE). The overarching goal of this project is to design, evaluate, and optimize a novel two-phase dark-light reactor (DRL) for the ex-situ treatment of groundwater contaminated by mixtures of PFAS and chlorinated solvents using magnetic and photochemically active nanomaterials. The successful completion of this project will benefit society through the generation of fundamental knowledge to advance the development and deployment of efficient and sustainable technologies for the treatment and remediation of groundwater aquifers contaminated by mixtures of PFAS and chlorinated solvents. Additional benefits to society will be achieved through student education and training including the mentoring of three graduate students at Southern Illinois University at Carbondale.In groundwater aquifers and subsurface formations, PFAS contaminants are often commingled with toxic chemicals such as chlorinated solvents including trichloroethylene (TCE) and tetrachloroethylene (PCE). However, to date, limited research has been devoted to the treatment and remediation of groundwater aquifers contaminated by mixtures of PFAS and chlorinated solvents. In addition, there is a critical need for pilot-scale studies to demonstrate and validate the feasibility and field-scale applicability of promising PFAS groundwater remediation technologies that are being investigated in bench scale laboratory studies. The goal of this research is to develop, evaluate, and validate the field-scale applicability of an integrated sorption-photocatalytic process for the ex-situ treatment and remediation of groundwater contaminated by mixtures of PFAS and TCE/PCE. To advance this goal, the Principal Investigator (PI) and research team propose to design, evaluate, and optimize a two-phase dark-light reactor (DRL) that will utilize nanomaterials under darkness to sorb PFAS and partially destroy TCE/PCE followed by exposure of the nanomaterials to UV light to destroy the remaining sorbed PFS and TCE/PCE contaminants. The specific objectives of the research are to 1) synthesize and characterize nanoscale zero-valent iron/reduced graphene oxide nanohybrids using an innovative and scalable process ; 2) conduct bench scale lab studies to assess the impacts of environmental factors on the efficiency of the DLR to remove PFAS and TCE/PCE in contaminated groundwater using the nanomaterials that are synthesized in Objective 1, and 3) conduct pilot field studies to evaluate and optimize the effectiveness of the new DRL and nanomaterials for the ex-situ treatment and remediation of groundwater contaminated by mixtures of PFAS and TCE/PCE. To implement the educational and outreach goals of this project, the PI plans to leverage the Research Enriched Challenge (REACH) program at Southern Illinois University at Carbondale to recruit and mentor undergraduate female students to work on the project. In addition, the PI plans to engage with the US Geological Survey (USGS) and the Illinois Environmental Protection Agency (EPA) to share the results of the research and discuss potential field applications/demonstrations of the new two-phase dark-light reactor at contaminated sites in the State of Illinois.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.