Project 6: Mass-Transfer and Mass-Flux Dynamics of Chlorinated Solvents

氯化有机溶剂化合物，如四氯乙烯，三氯乙烯和氯乙烯是美国最常见的地下水污染物之一，因为它们先前广泛用于许多工业和商业应用。鉴于其毒性、广泛存在和复杂的行为，氯化溶剂显然对人类健康和环境构成重大风险。本拟议项目旨在处理和帮助解决对受氯化溶剂污染场地的管理和关闭至关重要的问题。拟议研究的总体目标是提高风险评估的准确性，并提高受氯化溶剂污染场地的补救战略的有效性。指导拟议的研究的总体原则是，提高我们的机制为基础的，多尺度的理解的分布，传质和质量通量行为的氯化溶剂在非均质系统将加强风险评估，现场表征和修复工作。该项目旨在解决与美国各地受氯化溶剂污染的场地有关的问题，以及与西南部场地特别相关的问题。本项目的具体目标是：（1）提高我们对多相系统中不互溶液体的界面和传质行为的机理理解;（2）研究非均匀性、源区老化和难以进入的NAPL对水相和汽相系统长期质量通量动力学的影响;（3）确定质量去除、质量迁移和质量迁移。 通量和羽流收缩行为的氯化溶剂在现场规模，（4）测试的有效性的一种创新的方法，在现场表征的传质和质量通量，并比较这和现有的几种方法的性能，（5）整合过程信息跨越空间和时间尺度，以改善概念和数学模型。本项目旨在完成氯化溶剂不互溶液体在多尺度下的传质行为的系统研究，并研究系统性质对质量通量和羽流响应的影响。该项目包括综合孔隙规模，中间规模和现场规模的调查，以及数学建模分析。

Chlorinated organic solvent compounds such as tetrachloroethene, trichloroethene, and vinyl chloride are among the most common groundwater contaminants in the USA due to their prior widespread use for numerous industrial and commercial applications. Given their toxicity, widespread occurrence, and complex behavior, chlorinated solvents clearly pose a significant risk to human health and the environment. This proposed project is designed to address and help resolve issues that are critical to the management and closure of chlorinated-solvent contaminated sites. The overall goal of the proposed research is to enhance the accuracy of risk assessments and improve the effectiveness of remediation strategies for sites contaminated by chlorinated solvents. The overarching principle guiding the proposed research is that improving our mechanistic-based, multiple-scale understanding of the distribution, mass-transfer, and mass-flux behavior of chlorinated solvents in heterogeneous systems will enhance risk assessment, site characterization, and remediation efforts. The project is designed to address issues relevant to chlorinated-solvent contaminated sites across the USA, as well as those of particular relevance to sites in the Southwest. The specific aims to be addressed in this project are: (1) Improve our mechanistic understanding of the interfacial and mass-transfer behavior of immiscible liquids in multiphase systems, (2) Investigate the influence of heterogeneity, source-zone aging, and poorly-accessible NAPL on long-term mass-flux dynamics for aqueous and vapor-phase systems, (3) Determine the mass removal, mass flux, and plume contraction behavior of chlorinated solvents at the field scale, (4) Test the efficacy of an innovative method for in-situ characterization of mass transfer and mass flux, and compare the performance of this and several existing methods, (5) Integrate process information across spatial and temporal scales to improve conceptual and mathematical models. The project is designed to accomplish a systematic study of the mass-transfer behavior of chlorinated-solvent immiscible liquids at multiple scales, and to investigate the impact of system properties on mass flux and plume response. The project involves integrated pore-scale, intermediate-scale, and field-scale investigations, as well as mathematical modeling analysis.