Collaborative Research: ERASE-PFAS: Stabilization of Per- and Polyfluorinated Substances in Sewage Sludge Intended for Land-application

在美国，市政污水处理厂每年产生数百万吨污泥。对这种污泥的很大一部分进行处理，以产生一种营养丰富的产品，通常被称为生物固体。在美国，据估计，每年产生720万干公吨的生物固体，其中约55%的生物固体用作土壤改良剂，并在农业、农业和土地恢复中作为养分和有机物质的来源。生物固体中全氟和多氟烷基物质(PFAS)的检测引起了人们对这些固体在农业和农田应用中的持续和安全使用的严重关切。全氟化有机化学品是过去十年中出现的优先污染物，因为人们越来越担心它们的持久性、稳定性，以及它们在环境中积累时对人类和其他生物的毒性。这个合作项目的首要目标是识别、设计和合成合适的吸附剂，以结合和隔离生物固体中的全氟辛烷磺酸。该项目的成功完成将通过开发新的基础知识和吸着剂来减轻和消除在农业和农田应用中使用生物固体时植物对全氟辛烷磺酸的潜在吸收，从而使社会受益。还将通过外联和教育活动为社会带来更多好处，包括指导奥尔巴尼大学的一名研究生、亚利桑那大学的一名研究生和坦普尔大学的一名研究生。在美国，大约55%的从城市污泥中提取的生物固体被用作土壤改良剂、肥料，以及农业、农业和土地恢复中的养分和有机物质来源。在生物固体中检测到越来越多的全氟辛烷磺酸，引起了人们对其在农业和农田应用中的持续和安全使用的严重关切。该项目首席调查人员的初步工作证实，某些吸附剂可以隔离和稳定生物固体中的全氟烷基酸(PFA)。然而，关于生物固体中基于吸附的全氟辛烷磺酸的稳定仍有许多悬而未决的问题，包括它是否适用于广泛的全氟辛烷磺酸前体，稳定的全氟辛烷磺酸是否会长期固定在土壤中，以及稳定的全氟辛烷磺酸是否会被植物吸收。拟议的研究将解决这些关键的知识差距。为了推进这一目标，PIs建议进行一项综合的实验和模拟研究计划，以测试这样一种假设，即阴离子、阳离子或两性离子的PFAS前体可以通过适当的吸附剂在生物固体中稳定下来，这些吸附剂旨在增强目标吸附剂和PFAS前体之间的共价结合(通过头部基团相互作用)和吸附(通过尾基相互作用)。拟议的研究活动将围绕三项任务展开：1)调查添加或不添加吸附剂的厌氧消化污泥样品中PFAS前体的转化和分布；2)以大豆为模型植物，调查添加和不添加吸附剂的生物固体-土壤系统中PFAS前体的转化和分布；以及3)评估13C标记的PFAS前体及其混合物在实际污泥样本中的去向、转化和分布。该项目的成功完成具有潜在的变革性影响，通过发展新的基础知识来促进高效和经济高效的吸着剂的识别、设计和合成，这些吸着剂可以隔离和稳定生物固体中的全氟辛烷磺酸，使其能够继续和安全地用于农业和农地应用。为了实施项目的教育和外展活动，私人投资机构计划利用奥尔巴尼大学由纽约州教育部资助的现有计划(例如，大学科学与技术入门计划)来招募和指导两名初中生或高中生和两名本科生加入项目研究团队。此外，PIS计划建立一个网站来传播项目研究成果。这一奖项反映了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。

In the United States (US), municipal wastewater treatment plants generate millions of tons of sludge per year. A significant fraction of this sludge is treated to produce a nutrient-rich product commonly referred to as biosolids. In the US, it is estimated that 7.2 million dry metric tons of biosolids are produced annually with approximately 55% of the biosolids generated used as soil amendments and sources of nutrients and organic matter in agriculture, farming, and land restoration. The detection of per- and polyfluoroalkyl substances (PFAS) in biosolids has raised serious concerns about the continuing and safe use of these solids in agricultural and farming land applications. PFAS are fluorinated organic chemicals that have emerged as priority pollutants during the last decade due to increasing concerns about their persistence, stability, and toxicity to humans and other living organisms as they accumulate in the environment. The overarching goal of this collaborative project is to identify, design, and synthesize suitable sorbents that can bind and sequester PFAS in biosolids. The successful completion of this project will benefit society through the development of new fundamental knowledge and sorbents to mitigate and eliminate the potential uptake of PFAS by plants when biosolids are used in agriculture and farming land applications. Additional benefits to society will be achieved through outreach and educational activities including the mentoring of a graduate student at the University at Albany, a graduate student at the University of Arizona, and a graduate student at Temple University. Approximately 55% of the biosolids derived from municipal sludge in the US are used as soil amendments, fertilizers, and sources of nutrients and organic matter in agriculture, farming, and land restoration. The increasing detection of PFAS in biosolids is raising significant concerns about their continuing and safe use in agricultural and farming land applications. Preliminary work by the Principal Investigators (PIs) of this project has established that certain sorbents can sequester and stabilize perfluoroalkyl acids (PFAAs) in biosolids. However, there are a number of unanswered questions about this sorption-based stabilization of PFAS in biosolids including whether it is applicable to a wide range of PFAS precursors, whether the stabilized PFAS will remain immobilized in soils in the long term, and whether the stabilized PFAS will be taken up by plants. The proposed research will address these critical knowledge gaps. To advance this goal, the PIs propose to carry out an integrated experimental and modeling research program to test the hypothesis that anionic, cationic, or zwitterionic PFAS precursors can be stabilized in biosolids upon amendments with suitable sorbents designed to enhance covalent binding (via head group interactions) and adsorption (via tail group interactions) between the target sorbents and PFAS precursors. The proposed research activities will be structured around three tasks: 1) Investigation of the transformations and distributions of PFAS precursors in model anaerobically digested sludge samples with or without added sorbents; 2) Investigation of the transformations and distributions of PFAS precursors in biosolid-soil systems with or without added sorbents using soybeans as a model plant; and 3) Evaluation of the fate, transformations, and distributions of 13C-label PFAS precursors and their mixtures in real sludge samples. The successful completion of this project has the potential for transformative impact through the development of new fundamental knowledge to advance the identification, design, and synthesis of efficient and cost-effective sorbents that can sequester and stabilize PFAS in biosolids to enable their continuing and safe use in agricultural and farming land applications. To implement the education and outreach activities of the project, the PIs plan to leverage established programs at the University at Albany (e.g., the Collegiate Science & Technology Entry Program) funded by the New York State Department of Education to recruit and mentor two middle or high school students and two undergraduate students to work on the project research team. In addition, the PIs plan to set up a website to disseminate the project research findings.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.