CAREER: An Integrated Environmental Engineering Education and Research Plan to Enhance Molecular-Level Understanding of Sequestration Behavior of Volatile Organic Compounds

职业：综合环境工程教育和研究计划，以增强对挥发性有机化合物封存行为的分子水平理解

• 批准号: 9985159
• 负责人: Eugene LeBoeuf
• 金额: $ 27.5万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9985159&HistoricalAwards=false
• 关键词: CAREER; Integrated; Environmental; Engineering; Education

9985159 LeBoeuf Remediation of subsurface sites contaminated with volatile organic compounds (VOCs) costs the nation billions of dollars. The application of risk based approaches to the evaluation of contaminated sites requires an accurate understanding of the mechanisms controlling the transport and release of contaminants in the environment. This research addresses this issue by providing a basis for an improved molecular-level understanding of the mechanisms responsible for the sequestration of VOCs in the subsurface. The objectives are to: (1) determine the effects of natural organic matter composition on VOC sorption and desorption behavior; (2) determine the effects of soil and sediment nanoporosity on VOC sorption and desorption behavior; (3) predict VOC sorption and desorption behavior based on functional and structural characteristics of soils and sediments; (4) investigate mass transfer principles in the classroom using interactive teaching techniques and (5) determine how soil and sediment functional and structural characteristics affect field-scale evaluation of VOC fate and transport. An investigation of the functional and structural characteristics of natural organic matter (NOM) is used to understand the sequestration processes that control the fate and transport of organic contaminants in the subsurface. Temperature-modulated differential scanning calorimetry will be used to investigate glass transition, heat capacity and enthalpic relaxation behavior of NOMs. This information will provide insights to its structure and inherent macromolecular mobility. Use of positron annihilation lifetime spectroscopy (PALS) to probe the size, volume and hydrophobicity of NOM nanopores will provide an improved means to correlate nanopore structure with VOC sequestration behavior in soils and sediments. Comparisons of PALS measurements with N2, Ar and CO2 gas-based sorption data will provide increased knowledge of the ability of common gas-based measurements to characterize the nanoporosity of NOMs, model soils, and whole soils and sediments. The effects of the presence of a rubbery or glassy state of NOM and nanoporosity on VOC transport will be brought to life through development of a user-friendly, graphical-user-interface based finite element and finte difference mass transfer model. The use of this model in conjunction with developed case studies will provide an active learning environment emphasizing the use of fundamental concepts to more accurately predict contaminant behavior in real-world situations. Case studies, field trips and visits by practicing engineers will provide students a connection with real-world problems. Partnerships with Tennessee State University will provide opportunities to expose their undergraduate students to graduate-level research, while collaborations with Oak Ridge National Laboratory will significantly enhance the availability of research oportunities for both undergraduate and graduate students. ***

9985159 LeBoeuf修复受挥发性有机化合物（VOCs）污染的地下场地花费了国家数十亿美元。 应用基于风险的方法对污染场地进行评估，需要准确了解控制污染物在环境中迁移和释放的机制。 这项研究解决了这个问题，提供了一个基础，提高分子水平的理解机制负责封存的挥发性有机化合物在地下。 其目标是：（1）确定天然有机质组成对VOC吸附和解吸行为的影响;（2）确定土壤和沉积物纳米孔隙对VOC吸附和解吸行为的影响;（3）基于土壤和沉积物的功能和结构特征预测VOC吸附和解吸行为;（4）在课堂上使用互动教学技术研究质量传递原理;（5）确定土壤和沉积物的功能和结构特征如何影响VOC归宿和迁移的实地评估。 天然有机物（NOM）的功能和结构特征的调查是用来了解封存过程，控制的命运和运输的有机污染物在地下。 温度调制差示扫描量热法将被用来研究玻璃化转变，热容量和非晶松弛行为的NOMs。 这些信息将提供其结构和固有的大分子流动性的见解。 使用正电子湮没寿命谱（帕尔斯）探测NOM纳米孔的尺寸、体积和疏水性将提供一种改进的手段来将纳米孔结构与土壤和沉积物中的VOC封存行为相关联。 帕尔斯测量与N2，Ar和CO2气体为基础的吸附数据的比较将提供更多的知识的能力，常见的气体为基础的测量，以表征纳米孔隙度的NOMs，模型土壤，和整个土壤和沉积物。 橡胶态或玻璃态NOM和纳米孔隙度的存在对VOC传输的影响将通过开发一个用户友好的，基于图形用户界面的有限元和有限差分传质模型来实现。 结合开发的案例研究使用该模型将提供一个积极的学习环境，强调使用的基本概念，以更准确地预测污染物在现实世界中的行为。 案例研究，实地考察和实习工程师的访问将为学生提供与现实世界问题的联系。 与田纳西州立大学的合作伙伴关系将提供机会，让他们的本科生接触到研究生水平的研究，而与橡树岭国家实验室的合作将大大提高本科生和研究生的研究机会的可用性。***