CAREER: Targeted Catalytic Reduction of Persistent Organohalogens in Wastewater using a Novel V2C MXene-Imprinted Polymer Composite

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。有机卤素，如多氯联苯（PCB）和全氟烷基和多氟烷基物质（PFAS），由于其毒性，化学稳定性和在环境中的持久性，对环境和人类健康构成重大风险。通过水处理有效去除和破坏有机卤素污染物将需要新的和有针对性的方法，因为这些化合物通常以非常稀的浓度存在于饮用水源中。产生反应性溶剂化电子（SE）的处理技术是通过化学还原降解水溶液中有机卤素的有前途的方法。然而，基于SE的水处理工艺的功效受到与共存污染物的竞争反应以及溶剂化电子与饮用水源中存在的溶解的有机/无机物质之间的干扰反应的阻碍。该CAREER项目的总体目标是设计，合成，表征和评估能够进行目标分离和催化还原脱卤的新型复合介质，以解决当前SE水处理工艺的局限性。该项目的成功完成将通过产生新的水处理介质和基础知识来促进更有效和更具成本效益的技术的开发和部署，以消除和销毁饮用水源中的有机卤素污染物，从而造福社会。通过学生教育和培训，包括指导华盛顿大学的一名研究生和五名本科生，将为社会带来进一步的好处。多氯联苯和全氟磺酸等有机卤素在自然和工程水生系统中极其稳定。它们还能抵抗传统生物和化学水处理工艺的降解。在水溶液中产生溶剂化电子是一种很有前途的方法，可以裂解碳-卤键，促进受污染饮用水源中有机卤素的降解/破坏。然而，溶剂化电子（SE）很容易被清除，可能不会与目标有机卤素污染物反应，因为它们可能会被其他共同污染物和溶解的有机/无机物质消耗，这些物质通常存在于饮用水源中。这个CAREER项目将解决目前基于SE的水处理工艺去除有机卤素的关键限制。为了推进这一目标，主要研究者（PI）将探索开发新的复合介质，包括1）分子印迹聚合物外壳，可以选择性地提取有机卤素和2）碳化钒催化核心，具有产生溶剂化电子和降解有机卤素的潜力。研究的具体目标包括：（1）介质设计、合成和表征，（2）介质吸附能力和选择性的测量，（3）介质催化活性的实验研究，（4）在存在竞争性溶解有机/无机物种的复杂水基质中介质性能的评估;以及（5）介质可重复使用性的评估。该项目的成功完成具有潜在的变革性影响，通过产生基础知识，推动更高效、更具成本效益的介质的开发和部署，以去除饮用水源中的有机卤素污染物。为了实现这个职业生涯项目的教育和培训目标，PI将领导一个新开发的研讨会课程，高级本科生和研究生关于有机卤素的性质，暴露，毒性和补救。此外，PI和她的学生计划与Duwamish山谷青年团合作，设计一个文化上适当的讲习班，概述独特的有机卤素接触途径和与土著生活方式密切相关的风险，包括生存和饮食习惯。该奖项反映了NSF的法定使命，并被认为值得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来支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Organohalogens such as polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS) pose significant environmental and human health risks due to their toxicity, chemical stability, and persistence in the environment. The effective removal and destruction of organohologen pollutants by water treatment will require novel and targeted approaches as these compounds are often present at very dilute concentrations in drinking water sources. Treatment technologies which generate reactive solvated electrons (SE) are promising approaches to degrade organohalogens in aqueous solutions via chemical reduction. However, the efficacy of a SE-based water treatment process is hindered by competing reactions with co-occurring contaminants and interfering reactions between solvated electrons and dissolved organic/inorganic species present in drinking water sources. The overarching goal of this CAREER project is to design, synthesize, characterize, and evaluate new composite media capable of targeted separation and catalytic reductive dehalogenation to address the limitations of current SE-based water treatment processes. The successful completion of this project will benefit society through the generation of new water treatment media and fundamental knowledge to advance the development and deployment of more efficient and cost-effective technologies to remove and destroy organohalogen pollutants from drinking water sources. Further benefits to society will be achieved through student education and training including the mentoring of a graduate student and five undergraduate students at the University of Washington.Organohalogens such as PCBs and PFAS are extremely stable in natural and engineered aquatic systems. They are also resistant to degradation using conventional biological and chemical water treatment processes. The generation of solvated electrons in aqueous solutions is a promising approach to cleave carbon-halide bonds and facilitate organohalogen degradation/destruction in contaminated drinking water sources. However, solvated electrons (SE) are easily scavenged and may not react with the targeted organohalogen pollutants as they may be consumed by other co-contaminants and dissolved organic/inorganic species which often exist in drinking water sources. This CAREER project will address the critical limitations of current SE-based water treatment processes for organohalogen removal. To advance this goal, the Principal Investigator (PI) will explore the development of new composite media consisting of 1) molecularly imprinted polymer shells that can selectively extract organohalogens and 2) vanadium carbide catalytic cores with demonstrated potential to generate solvated electrons and degrade organohalogens. The specific objectives of the research include: (1) media design, synthesis, and characterization, (2) measurements of media sorption capacity and selectivity, (3) experimental investigations of media catalytic activity, (4) evaluation of media performance in complex water matrices in the presence of competing dissolved organic/inorganic species; and (5) evaluation of media reusability. The successful completion of this project has the potential for transformative impact through the generation of fundamental knowledge to advance the development and deployment of more efficient and cost-effective media to remove organohalogen contaminants from drinking water sources. To implement the educational and training goals of this CAREER project, the PI will lead a newly developed seminar course for senior-level undergraduate and graduate students about organohalogen properties, exposure, toxicity, and remediation. Additionally, the PI and her students plan to partner with the Duwamish Valley Youth Corps to design a culturally appropriate workshop outlining unique organohalogen exposure pathways and risks closely associated with indigenous lifestyles including subsistence and dietary practices.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.