Collaborative Research: Exploration of the Interplay between Contaminant Partitioning and Biotransformation in Multiphase Porous Media

合作研究：探索多相多孔介质中污染物分配与生物转化之间的相互作用

• 批准号: 0711344
• 负责人: Andrew Ramsburg
• 金额: $ 27.41万
• 依托单位: Tufts University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0711344&HistoricalAwards=false
• 关键词: Collaborative; Research; Exploration; Interplay; between

Biological technologies aimed at cleaning up aquifers contaminated by nonaqueous phase liquids (NAPLs) frequently produce multiple degradation products which may or may not represent an overall reduction of the risk posed to human health. Understanding the fate and transport of these degradation products within a multiphase subsurface environment is critical given the interest in applying bioenhanced dissolution for remediation of sites contaminated by chlorinated solvent NAPLs. Assessing the fate and transport of biological degradation products in multifluid subsurface environments requires knowledge of the interplay between physical, chemical, and biological processes. At the center of this interplay is bioavailability of degradation products influencing contaminant fate. Bioavailability is influenced by the kinetics of mass transfer processes active in multiphase subsurface environments. This research project integrates laboratory experiments and mathematical modeling to explore how kinetics of interphase mass transfer influences rates of biodegradation and degradation product accumulation in NAPL source zones containing chloroethenes. Specific objectives are: (1) identify the capacity of chloroethene NAPLs to reversibly sequester cis-dichloroethene and vinyl chloride, (2) investigate the rates of mass transfer of these degradation products within heterogeneous porous media containing chloroethene NAPLs, and (3) understand the significance of these processes in the context of field-scale, bioactive, NAPL source zones.Intellectual Merit: Knowledge gained from this research will increase the understanding of parent and daughter products bioavailability within subsurface environments. In addition, quantitative descriptions of the complex interplay between the rates of mass transfer and biotransformation will complement ongoing efforts in other laboratories that are aimed at assessing the levels at which chloroethenes inhibit the microbial species involved in metabolic reductive dechlorination. Implementation of the developed descriptions for the coupled rates of mass transfer and biotransformation within formations containing heterogeneously distributed NAPL will ultimately enable more accurate assessment of the application of bioremediation technologies for groundwater clean-up.Broader Impacts: The research project fosters education at a number of academic levels, and provides a unique collaborative environment for training of students working at both Tufts and the U.S. Air Force Academy. Research is being integrated into the undergraduate experience through: (1) undergraduate research projects directly related to the goals of the proposed research; (2) the development of research-based model-eliciting activities (MEAs) for implementation within undergraduate engineering curricula, and (3) outreach to high school students in the Colorado Springs and Boston metropolitan areas implemented through the US Air Force Academy's Center for Educational Excellence and through the Tufts Center for Engineering Education Outreach.

旨在清理受非水相液体污染的含水层的生物技术经常产生多种降解产物，这些产物可能代表也可能不代表对人类健康构成的风险全面减少。了解这些降解产物在多相地下环境中的命运和运输是至关重要的，因为有兴趣应用生物增强溶解来修复被氯化溶剂napl污染的场所。评估多流体地下环境中生物降解产物的命运和运输需要了解物理、化学和生物过程之间的相互作用。这种相互作用的中心是影响污染物命运的降解产物的生物利用度。生物利用度受多相地下环境中活跃的传质过程动力学的影响。本研究项目将实验室实验和数学模型相结合，探索相间传质动力学如何影响含氯乙烷的NAPL源区生物降解速率和降解产物积累。具体目标是：(1)确定氯乙烯NAPLs可逆吸附顺式二氯乙烯和氯乙烯的能力，(2)研究这些降解产物在含有氯乙烯NAPLs的非均质多孔介质中的传质速率，以及(3)了解这些过程在现场规模、生物活性、NAPL源区背景下的重要性。智力价值：从本研究中获得的知识将增加对母体和子代产品在地下环境中的生物利用度的理解。此外，对质量传递率和生物转化率之间复杂相互作用的定量描述将补充其他实验室正在进行的旨在评估氯乙烯抑制参与代谢还原脱氯的微生物种类水平的工作。在含有非均匀分布的NAPL的地层中，对质量传递和生物转化耦合速率的开发描述的实施将最终能够更准确地评估地下水净化生物修复技术的应用。更广泛的影响：该研究项目促进了多个学术水平的教育，并为在塔夫茨大学和美国空军学院工作的学生提供了一个独特的合作环境。通过以下方式将研究融入本科生体验：(1)与拟研究目标直接相关的本科生研究项目；(2)开发以研究为基础的模型引出活动（MEAs），在本科工程课程中实施；(3)通过美国空军学院卓越教育中心和塔夫茨工程教育推广中心向科罗拉多斯普林斯和波士顿大都市地区的高中生推广。