Collaborative Research: ERASE-PFAS: Remediation of Per- and Polyfluoroalkyl Substances in Wastewater using Anaerobic Membrane Bioreactors​

全氟烷基和多氟烷基物质（PFAS）用于许多消费品和工业产品。全氟辛烷磺酸已在家庭饮用水系统中发现，并已在全球生态系统中得到确认。PFAS在环境中具有高度持久性，因此被称为“永远的化学物质”。由于PFASs对人类和野生动物有毒，因此找到有效的方法来消除这些化学品是很重要的。本研究的目标是通过开发厌氧膜生物反应器（AnMBR）来解决这一需求，该反应器依赖于细菌和膜来去除和破坏水中的PFASs。这一目标将通过一个多阶段的研究计划来实现，以开发使用新的分子生物学方法转化PFAS的微生物培养物，表征治疗前后的PFAS转化过程，并使用最先进的科学方法评估最终产品的反应性。这项研究的成功完成将使我们能够更好地了解细菌如何降解PFAS，并确定降解如何影响这些产品的毒性。社会效益包括潜在的技术开发，以满足低成本，有效的PFAS处理的迫切国家需求。其他好处包括通过推广、招募和培训提高科学素养和STEM多样性。PFAS的广泛使用和极端稳定性导致其在环境中无处不在。PFASs对生物降解的抑制作用是由碳-氟键的惰性引起的，这一点人们还知之甚少。然而，在还原条件下，还原脱乙酰基是有利的，这是一个令人困惑的发现，值得进一步探索使用新兴的化学和分子生物技术工具。该项目通过对AnMBR中PFASs生物降解的多阶段调查来满足这一需求。AnMBR将厌氧处理与膜分离联合收割机结合起来，提供低能耗的生物处理。该项目的总体目标是开发一套工具，以更好地了解PFAS生物处理。i）证明AnMBR中PFAS的还原脱氟，并使用乳液、配对分离和串联（epic）PCR鉴定脱氟微生物种群，以在细胞水平上将系统发育基因与脱卤基因联系起来; ii）使用高分辨率液相色谱表征生物转化产物并评估降解效率，质谱和19 F核磁共振光谱;和iii）使用整合的转录组学和代谢组学方法系统地评价PFAS混合物在哺乳动物细胞系中的生物活性。这项研究的成功完成具有强大的潜力，可以改变我们对传统和新兴PFAS水处理系统的知识。这些信息可以导致有效的生物处理替代PFAS，解决关键的国家需求。更广泛的科学和社会影响包括在目前的做法建立PFAS健康体系的范式转变的潜力应在复杂的PFAS混合物的协同作用的证据建立。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Per- and polyfluoroalkyl substances (PFASs) are used in many consumer and industrial products. PFASs have been found in domestic drinking water systems and have been identified in ecosystems on a global basis. PFASs are highly persistent in the environment, and as such have been called ‘forever chemicals.’ Because PFASs are toxic to humans and wildlife, it is important to find efficient ways to eliminate these chemicals from water supplies. The goal of this research is to address this need through the development of anaerobic membrane bioreactors (AnMBRs) that rely on both bacteria and membranes to remove and destroy PFASs from water. This goal will be achieved through a multiphase research program to develop microbial cultures that transform PFAS using novel molecular biological approaches, characterize the PFAS transformation process before and after treatment, and assess the reactivity of end products using state-of-the-science approaches. Successful completion of this research will allow us to better understand how bacteria degrade PFASs and determine how degradation affects the toxicity of these products. Societal benefits include potential development of technology to address the urgent national need for low cost, effective PFAS treatment. Additional benefits include increasing scientific literacy and STEM diversity through outreach, recruitment, and training.The widespread use and extreme stability of PFASs have resulted in their ubiquitous occurrence in the environment. The recalcitrance of PFASs to biodegradation resulting from the inertness of carbon-fluorine bonds is poorly understood. However, reductive defluorination is thermodynamically favorable under reducing conditions, a puzzling finding that warrants further exploration using emerging chemical and molecular biotechnological tools. This project addresses this need through a multi-stage investigation of the biodegradation of PFASs in AnMBRs. AnMBRs combine anaerobic treatment with membrane separation, providing low-energy intensive biological treatment. The overall goal of this project is to develop a set of tools leading to a better understanding of PFAS biotreatment. The specific objectives designed to achieve this goal are to: i) demonstrate reductive defluorination of PFASs in AnMBRs and identify defluorinating microbial populations using emulsion, paired isolation, and concatenation (epic)PCR to link phylogenetic genes with dehalogenation genes at a cellular level; ii) characterize biotransformation products and assess degradation efficiency using high resolution liquid chromatography/mass spectrometry and 19F nuclear magnetic resonance spectroscopy; and iii) systematically evaluate biological activity of PFAS mixtures in mammalian cell lines using an integrated transcriptomics and metabolomics approach. Successful completion of this research holds strong potential to transform our knowledge of water treatment systems for legacy and emerging PFASs. Such information can lead to efficient biological treatment alternatives for PFAS, addressing a critical national need. Broader scientific and societal impacts include the potential for a paradigm shift in current practices for establishing PFAS health advisories should evidence of synergistic interactions in complex PFAS mixtures be established.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.