CAREER: Leveraging the multifunctional redox properties of pyrogenic materials to enable biological transformations of aqueous organic contaminants

过去释放的有毒有机污染物造成的污染继续困扰着这个国家的水、土壤和沉积物。虽然已经开发了各种技术和方法来修复这些遗留污染物，但它们继续给全国各地的社区带来挑战。这一职业项目的总体目标是通过开发以具有成本效益的方式更完全地降解有毒有机污染物的处理技术，来应对这些挑战并保护人类和环境健康。这项技术的基础是一种混合微生物-材料过程。在这种方法中，微生物提供了驱动力，使材料表面的反应能够降解有机污染物。虽然这一进程显示出了巨大的希望，但我们对这一进程如何发生的了解存在许多空白。所获得的基本洞察力将使能够降解特定污染物的材料的知情设计和优化成为可能。然后，这些材料可以应用于水和废水处理厂等工程系统。综合教育计划将产生重大而广泛的影响，并将通过与北卡罗来纳州科学和数学学院合作的针对代表性不足的高中生的辅导计划，接触到不同的K-12教师和学生受众。这些努力将提高国家的科学素养，并有助于发展未来的STEM劳动力。这个职业项目的总体目标是研究氧化还原活性材料中微生物驱动的电子转移如何转化有机污染物的基本机制。传统的生物处理有机污染物的方法，如氯化溶剂，依赖于特定细菌的活性。这些细菌的丰度通常很低，并且稀疏地分布在地下，利用这些细菌的活性的材料可以大大增强和维持污染物的去除。地杆菌是一类存在于水、土壤和沉积物中的细菌，它们在代谢方面具有极强的多样性，能够利用不溶性电子受体，如热解碳质材料(PCMs)。地质细菌使用相变材料，如活性碳和生物炭，在材料中穿梭电子，以非生物方式降解材料表面的污染物。PI将结合电化学、显微镜、光谱学和分子生物学的工具，解决我们在理解微生物-材料-污染物界面上的这些相互作用方面的知识空白。拟议的计划将追求三个补充目标：(1)确定相变材料的性质对微生物和污染物反应性的作用，(2)评估污染物吸附对反应动力学和对微生物的毒性的作用，以及(3)确定环境基质成分对相变材料介导的反应的弹性的影响。有了这些信息，可以设计新一代材料来降解饮用水、雨水和生物修复系统等应用中的有机污染物。研究目标将与创新教育举措相结合。K-12生物学教师将学习先进的显微镜和实验试剂盒，向学生介绍环境微生物学。与星期五教育创新研究所的合作将利用这些活动，通过学校与一年一度的NC科学教师协会会议的现有合作伙伴关系，接触到数百名K-12教师和学生。北卡罗来纳州科学与数学学院将试行一项针对未被充分代表的高中生的多层次辅导计划，以提供研究经验，帮助学生在STEM就业。最后，将在NCSU开发一个新的本科生级别的PCM微生物反应性实验室。该奖项反映了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。

Pollution from past releases of toxic organic contaminants continue to plague the Nation’s water, soil, and sediment. While various technologies and approaches have been developed to remediate these legacy pollutants, they continue to present challenges for communities around the country. The overall goal of this CAREER project is to address these challenges and protect human and the environmental health by developing treatment technologies that more completely degrade toxic organic pollutants in a cost-effective manner. The basis for this technology is a hybrid microbial-material process. In this approach, microorganisms provide the driving force to enable reactions on the surface of materials that degrade the organic pollutant. While this process has shown great promise, there are many gaps in our knowledge of how this process occurs. The fundamental insight gained will permit the informed design and optimization of materials that can degrade specific pollutants. These materials can then be applied to engineered systems such as water and wastewater treatment plants. The integrated education plan will have significant and broad impacts and will reach a diverse audience of K-12 teachers and students through a mentoring program for underrepresented high school students in partnership with the NC School of Science and Mathematics. These efforts will increase the scientific literacy of the Nation and help develop the STEM workforce of the future.The overall goal of this CAREER project is to study the fundamental mechanisms of how microbial-driven electron transfer from redox-active materials transform organic contaminants. Conventional methods for the biological treatment of organic contaminants like chlorinated solvents rely on the activity of specific bacteria. These bacteria are often low in abundance and sparsely distributed in the subsurface, and materials that harness the activity of these bacteria can greatly enhance and sustain contaminant removal. Geobacter, a group of bacteria that are present in water, soil, and sediment are extremely metabolically versatile in their ability to utilize insoluble electron acceptors such as pyrogenic carbonaceous materials (PCMs). Geobacter use PCMs such as activated carbon and biochar to shuttle electrons through the material to abiotically degrade contaminants on the material surface. The PI will combine the tools of electrochemistry, microscopy, spectroscopy, and molecular biology to address knowledge gaps in our understanding of these interactions at microbial-material-contaminant interfaces. Three complimentary goals in the proposed program will be pursued: (1) Determine the role of PCM properties on microbial and contaminant reactivity, (2) Assess the role of contaminant adsorption on reaction kinetics and toxicity to the microorganisms, and (3) Determine the effect of environmental matrix components on the resiliency of reactions mediated by PCMs. With this information, a new generation of materials can be designed to degrade organic pollutants in applications including drinking water, stormwater, and bioremediation systems. The research objectives will be integrated with innovative education initiatives. K-12 teachers in biology will learn advanced microscopy and experiment kits to introduce students to environmental microbiology. Collaboration with the Friday Institute for Educational Innovation will leverage these activities to reach hundreds of K-12 teachers and students through existing school partnerships with the annual NC Science Teachers Association Conference. A multi-level mentoring program for underrepresented high school students will be piloted at the NC School of Science and Mathematics to provide research experiences to help students pursue careers in STEM. Finally, a new undergraduate-level lab on PCM microbial reactivity at will be developed at NCSU.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.