CAREER: Natural Organic Matter Mediated Processes in the Subsurface: Heavy Metal Adsorption and Nanoparticle Migration

0954991 Lenhart天然有机物（NOM）是天然生物和化学过程的产物，是自然界中普遍存在的不同大小和反应性的有机分子的异质混合物。NOM控制污染物和颗粒的环境命运，这个职业发展计划将阐明NOM酸如何影响土壤和地下水系统中铅和纳米颗粒氧化铁的命运的具体细节。具体的研究目标是：（a）表征NOM酸在氧化铁/水界面上的配位结构，并确定酸如何影响相同界面上的铅配位，以及（B）将NOM酸在氧化铁/水界面上的配位模式和结构与纳米尺寸的氧化铁颗粒通过多孔介质的最终传输相关联。该研究将结合联合收割机原子，分子，微观和宏观水平的技术与流体动力学活性实验，以提供直接的信息前所未有的详细铅形态和纳米颗粒的运输受NOM的影响。该研究将阐明具体的详细信息NOM协调在矿物界面。目前的反应性运输和化学形态模型没有适当地考虑这些相互作用，并产生错误的预测。将确定NOM的不同组分，即已知结构的酸和异质结构的酸，对确定重金属行为的作用。在NOM存在下，纳米尺寸的赤铁矿通过多孔介质的运输研究将有助于环境纳米科学和纳米技术的新兴领域，并将提供评估环境中纳米颗粒风险所需的信息。宏观，微观，分子和原子水平的NOM和铅吸附技术的新组合将提供无与伦比的分辨率的信息。 除了对污染场地管理和颗粒迁移的直接益处外，从这项工作中收集的详细信息也将有利于原位污染物修复和水处理的研究。解决我们社会所面临的严重环境问题需要具有广泛不同背景的科学家、工程师和政策制定者的共同努力。要使这些人做好承担这一任务的准备，就需要有一个教育制度，强调为所有学生提供适用于环境的自然科学和物理科学方面的坚实基础。该教育计划的目标是建立一个框架，将合理的环境科学和工程概念传授给STEM管道的多个组成部分，从中学到研究生院，以及各种种族，社会和性别群体的学生。为了实现这一教育目标，PI将通过专业发展和电子视频会议计划向K-12教师和学生进行推广，将本科生和研究生融入多学科团队，并通过结合现实世界的例子，团队作业和专业实践主题来提高研究生和本科生课程的学习成果。综合研究和教育工作将覆盖广泛的受众，并通过外联和招聘活动，增加不同群体对科学和工程的参与。外联活动将覆盖当地社区和全国各地的K-12学生和教师。 科学成果的传播将是广泛的，并将有助于环境工程，环境化学，表面化学和水地球化学领域。 新的课程内容将包括关键技能，如团队合作，领导能力和解决问题的能力，从而更好地为学生毕业后的职业成功做好准备。 改善机制和结构信息的重金属形态在异质系统中将有利于社会通过改善现场修复和管理的做法。 关于纳米级赤铁矿迁移的详细信息还将提供制定管理人为纳米材料排放的监管制度所需的具体信息。 最后，预计密切协调研究、教育和外联活动将促进所有参与者更好地认识研究和工程在社会中的重要性和应用。

0954991Lenhart Natural organic matter (NOM), the product of natural biological and chemical processes, is a heterogeneous mixture of organic molecules of varying size and reactivity that is ubiquitous in nature. NOM controls the environmental fate of contaminants and particles and this career development plan will elucidate specific details of how NOM acids of environmental significance influence the fate of lead and nanoparticulate iron oxides in soil and ground water systems. The specific research objectives are to: (a) characterize the coordination structures of NOM acids at iron oxide/water interfaces and determine how the acids influence lead coordination at the same interfaces, and (b) relate the coordination modes and structures of NOM acids at iron oxide/water interfaces to the resultant transport of nano-sized iron oxide particles through porous media. The research will combine atomic-, molecular-, microscopic-, and macroscopic-level techniques with hydrodynamically-active experiments in order to provide direct information of unprecedented detail on lead speciation and nanoparticle transport as influenced by NOM. The research will elucidate specific detailed information of NOM coordination at mineral interfaces. Current reactive transport and chemical speciation models do not appropriately account for these interactions and produce erroneous predictions. The role that different components of NOM, namely acids of known structure and those of heterogeneous structure, have on determining heavy metal behavior will be determined. Research on the transport of nano-sized hematite through porous media in the presence of NOM will contribute to the emerging fields of environmental nanoscience and nanotechnology and will provide information needed to assess the risk of nanoparticles in the environment. The novel combination of macroscopic-, microscopic-, molecular-, and atomic-level techniques for NOM and lead adsorption will provide information of unsurpassed resolution. In addition to the direct benefits to contaminated site management and particle transport, the detailed information collected from this work will also benefit research on in situ contaminant remediation and water treatment. Solving the critical environmental problems our society faces will require a concerted effort by scientists, engineers, and policy makers with widely varying backgrounds. Preparing these individuals for such a task requires an educational system that places emphasis on providing all students with a sound foundation in the natural and physical sciences as they apply to the environment. The goal of this educational plan is to establish a framework to impart sound environmental science and engineering concepts to multiple components of the STEM pipeline, from middle school through graduate school and to students across a spectrum of ethnic, social, and gender groups. To meet this educational goal the PI will perform outreach to K-12 teachers and students through professional development and electronic videoconferencing initiatives, integrate undergraduate and graduate students into multi-disciplinary teams, and enhance learning outcomes in graduate and undergraduate courses by incorporating real-world examples, team-based assignments, and professional practice topics. The integrated research and education efforts will reach a wide audience, and through outreach and recruitment activities, will increase the participation of diverse groups in science and engineering. Outreach initiatives will reach out to K-12 students and teachers in the local community and across the country. Dissemination of the scientific results will be wide and will contribute to the fields of environmental engineering, environmental chemistry, surface chemistry, and aqueous geochemistry. New course components will incorporate critical skills such as team-work, leadership and problem-solving thereby better preparing students for professional success upon graduation. The improved mechanistic and structural information of heavy metal speciation in heterogeneous systems will benefit society by improving site remediation and management practices. The details on the transport of the nano-sized hematite will also provide specific information needed to develop a regulatory system to manage the discharge of anthropogenic nanomaterials. Finally, it is expected that closely coordinating the research, educational and outreach activities will foster a greater awareness among all participants of the importance and application of research and engineering in society.