CAREER: Transport of perfluoroalkyl substances (PFAS) in partially and fully saturated porous media - evaluating the interactions of solution chemistry and organic matter quality

职业：全氟烷基物质 (PFAS) 在部分和完全饱和多孔介质中的传输 - 评估溶液化学和有机物质量的相互作用

• 批准号: 1944639
• 负责人: Erica McKenzie
• 金额: $ 50万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1944639&HistoricalAwards=false
• 关键词: CAREER; Transport; perfluoroalkyl; substances; PFAS

Poly and perfluoroalkyl substances (PFAS) are man-made chemicals. PFAS have been used in a variety of products due to their stability and other valuable chemical properties. However, PFAS this stability also makes PFAS difficult to biodegrade in the environment. In addition, their properties also pose a threat to human health and the environment. It is estimated that over six million Americans have been exposed to PFAS in the water supply, and PFAS is considered one of the most important issues in environmental contamination facing the Nation. This concern results from studies that have shown that some PFAS can enter and remain in the human body, potentially causing cancer and other health problems. This knowledge has led to many efforts to treat water sources to remove PFAS when discovered. Pumping and treatment of groundwater is one of these commonly used treatment approaches. While this approach has worked for some pollutants, the PFAS movement in groundwater is difficult to predict because we do not fully understand the interactions between PFAS and natural organic matter (NOM) present in soil. The goal of this CAREER project is to address this knowledge gap by investigating the interactions of NOM and PFAS. This will be achieved through a series of experiments with well characterized model systems. Understanding this process will allow us to improve groundwater treatment systems to protect human health. This work will be used to educate the public through outreach to increase awareness of PFAS challenges and efforts to address these concerns. These efforts will increase the scientific literacy of the Nation while educating the public on important health issues.The goal of this CAREER proposal is to identify the mechanisms of PFAS interactions with organic matter in soils. This will be achieved using a range of conventional and novel analytical approaches to assess how organic matter, cations, and PFAS interact through a framework including solution phase complexation and accumulation at air-water and solid-water interfaces. Mechanistic insights gained from this research could explain previously observed variability in sorption distributions and rate constant values. The proposed work will combine batch, static column, and flow-through column experiments to assess PFAS transport from a near surface sources through the vadose zone and saturated groundwater. An idealized porous media system will be created using polymer-coated beads, where the polymers will be employed as homogeneous well-defined soil organic matter proxies. Mechanistic insights will be enabled through the use of organic matter proxies to elucidate how chemical moieties affect PFAS-organic matter interactions. PFAS complexation by dissolved organic matter and cation binding constants will be determined based on co-elution in size exclusion chromatography. Air-water interfacial accumulation will be evaluated using droplet contact angle coupled with stacked multi-ring static columns operated in drainage and secondary imbibition modes. Finally, PFAS transport in flow-through columns will be completed using continuous effluent analysis by high resolution mass spectrometry to quantify PFAS concentrations in the column effluent. The project includes a multi-component outreach effort: 1) educational activities will focus on outreach to middle and high school students, 2) research opportunities for undergraduate students from a range of disciplines, and 3) development of multi-disciplinary thinking in graduate students. These efforts will benefit the Nation through increased scientific literacy and enhancement of the Nation’s STEM workforce.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.

聚氟烷基物质（PFA）是人造化学物质。 PFA由于其稳定性和其他有价值的化学特性而用于多种产品中。但是，PFAS这种稳定性也使PFA在环境中难以生物降解。此外，它们的特性还对人类健康和环境构成威胁。据估计，超过600万美国人在供水中暴露于PFA，而PFA被认为是该国面临的环境污染中最重要的问题之一。这一研究的结果是研究表明，一些PFA可以进入并留在人体中，可能导致癌症和其他健康问题。这些知识导致了许多努力治疗水源以在发现时去除PFA。地下水的抽水和处理是这些常用的治疗方法之一。尽管这种方法适用于某些污染物，但很难预测地下水中的PFAS运动，因为我们不完全了解土壤中存在的PFA与天然有机物（NOM）之间的相互作用。这个职业项目的目的是通过调查NOM和PFA的互动来解决这一知识差距。这将通过一系列具有良好表征模型系统的实验来实现。了解这一过程将使我们能够改善地下水处理系统以保护人类健康。这项工作将用于通过外展来教育公众，以提高人们对PFAS挑战的认识和解决这些问题的努力。这些努力将提高国家的科学素养，同时对公众就重要的健康问题进行教育。这项职业建议的目的是确定PFAS与土壤中有机物的相互作用的机制。这将使用一系列常规和新颖的分析方法来评估有机物，阳离子和PFA如何通过框架相互作用，包括溶液相络合和在空气水和固体水接口处的积累。从这项研究中获得的机械洞察力可以解释以前观察到的溶液分布和速率恒定值的可变性。拟议的工作将结合批处理，静态柱和流通柱实验，以评估从近表面源通过vadose区和饱和地下水的PFA运输。将使用涂有聚合物的珠子创建理想化的多孔介质系统，在该珠子中，聚合物将被雇用为均匀定义的土壤有机物代理。通过使用有机物代理来阐明化学部分如何影响PFAS和有机物的相互作用，将实现机械洞察力。溶解有机物和阳离子结合常数的PFA络合将基于大小排除色谱法的共同布置确定。将使用液滴接触角以及在排水和次要吸收模式下操作的堆叠的多环静态柱的液滴接触角度评估空气水界面积累。最后，通过高分辨率质谱法连续有效分析，将完成流通柱中的PFA传输，以量化柱中的PFA浓度有效。该项目包括一项多组件外展工作：1）教育活动将集中于中学和高中生的宣传，2）来自一系列学科的本科生的研究机会，以及3）在研究生中发展多学科思维。这些努力将通过提高科学素养和增强国家STEM劳动力的能力使国家受益。该奖项反映了NSF的法定使命，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估标准通过评估来支持的。