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（多氯联苯）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素污染物将需要新的和有针对性的方法，因为这些化合物在饮用水源中的浓度通常非常低。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的有机卤素的有前途的方法。然而，基于se的水处理工艺的效果受到与共存污染物的竞争反应以及饮用水源中存在的溶剂化电子与溶解的有机/无机物质之间的干扰反应的阻碍。CAREER项目的总体目标是设计、合成、表征和评估能够进行定向分离和催化还原脱卤的新型复合介质，以解决当前基于se的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开发和部署更有效和更具成本效益的技术，以去除和破坏饮用水源中的有机卤素污染物，从而造福社会。进一步的社会效益将通过学生教育和培训来实现，包括在华盛顿大学指导一名研究生和五名本科生。有机卤素如多氯联苯和PFAS在天然和工程水生系统中非常稳定。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切割碳卤化物键和促进有机卤素降解/破坏污染饮用水水源的方法。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发生反应，因为它们可能被饮用水源中经常存在的其他共污染物和溶解的有机/无机物质消耗。这个CAREER项目将解决目前基于se的水处理工艺在去除有机卤素方面的关键限制。为了推进这一目标，首席研究员（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；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。具体的研究目标包括：(1)介质的设计、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/无机物质的复杂水基质中评估介质的性能；(5)介质可重用性评价。该项目的成功完成有可能产生变革性的影响，通过产生基础知识，推动开发和部署更有效和更具成本效益的介质，从饮用水源中去除有机卤素污染物。为了实现该职业项目的教育和培训目标，PI将领导一门新开发的研讨会课程，面向高年级本科生和研究生，内容涉及有机卤素的特性、暴露、毒性和补救。此外，PI和她的学生计划与杜瓦米什山谷青年团合作，设计一个适合文化的研讨会，概述与土著生活方式密切相关的独特有机卤素暴露途径和风险，包括生存和饮食习惯。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。

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.