Mass-Transfer Dynamics of Chlorinate

氯酸盐的传质动力学

• 批准号: 6901475
• 负责人: MARK BRUSSEAU
• 金额: $ 15.59万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6901475
• 关键词: adsorption; biotransformation; chlorination; environmental transport; fluid flow; mathematical model; model design /development; organic chemicals; soil; soil microbiology; soil pollution; solvents; water pollution

Organic chemicals in the form of nonaqueous-phase (immiscible) organic liquids (NAPLs) occur in the subsurface at numerous contaminated sites and act as long-term sources of groundwater contamination. Effective risk assessment and remediation at these sites depends on the ability to accurately characterize the mass transfer of components between NAPL and groundwater (NAPL dissolution). The factors influencing dissolution of NAPLs have been examined in detail at the laboratory column scale. However, the fundamental dissolution behavior of NAPLs at the pore scale is not well understood. In addition, minimal research has been conducted to examine the impact of porous-medium heterogeneity on NAPL dissolution. The overall goal of the proposed research is to better understand the dissolution behavior of dense nonaqueous-phase, immiscible organic liquids (DNAPLs) in subsurface systems. The specific objectives developed to accomplish this goal are: (1) Investigate the dissolution dynamics of DNAPLs at the pore scale. (2) Develop and apply a lattice/network model to simulate dissolution dynamics at the pore scale. (3) Investigate the impact of porous-medium heterogeneity on DNAPL dissolution. (4) Investigate the impact of porous-medium heterogeneity on the efficacy of hydraulic-based source-zone remediation technologies. (5) Develop and evaluate advanced mathematical models capable of simulating the dissolution and transport of DNAPL constituents in heterogeneous porous media at multiple scales. The experiments are designed to investigate the impact of porous-medium properties on NAPL morphology and distribution, and the resultant effect on dissolution and mass-flux behavior. Experiments will be designed to allow investigation of complete dissolution and mass removal. The project involves both pore-scale and macro-scale investigations. In both cases, advanced imaging methods will be used to obtain direct, in-situ measurements of NAPL configuration and dissolution dynamics. This information will be integrated with measurements of mass flux data. Advanced mathematical modeling will be employed to help synthesize and interpret the results of the experiments. The project makes use of two National Laboratory user facilities that provide the opportunity to use advanced imaging techniques that would otherwise not be available.

非水相（不混溶）有机液体（NAPLs）形式的有机化学品存在于许多污染场地的地下，并成为地下水污染的长期来源。在这些地点进行有效的风险评估和补救取决于准确描述非水溶性液体和地下水之间的物质转移（非水溶性液体溶解）的能力。在实验室柱规模下，详细考察了影响非质子液体的溶出度的因素。然而，NAPLs在孔隙尺度上的基本溶解行为还没有得到很好的理解。此外，已经进行了最少的研究，以检查多孔介质的非均质性对NAPL溶解的影响。拟议研究的总体目标是更好地了解地下系统中致密非水相、不混溶有机液体（DNAPL）的溶解行为。具体 为实现这一目标而开发的目标是：（1）研究DNAPL在孔尺度上的溶解动力学。(2)开发并应用晶格/网络模型来模拟孔隙尺度下的溶解动力学。(3)研究多孔介质异质性对DNAPL溶出的影响。(4)调查多孔介质异质性对基于水力的源区补救技术的影响。(5)开发和评估先进的数学模型，能够在多个尺度上模拟DNAPL成分在非均质多孔介质中的溶解和传输。实验旨在研究多孔介质性质对NAPL形态和分布的影响，以及由此产生的对溶解和质量通量行为的影响。实验设计将允许研究完全溶解和质量去除。该项目涉及孔隙尺度和 宏观调查。在这两种情况下，先进的成像方法将被用来获得直接的，原位测量的非水相液体配置和溶解动力学。这一信息将与质量通量数据的测量相结合。将采用先进的数学建模来帮助综合和解释实验结果。该项目利用了两个国家实验室用户设施，这些设施提供了使用先进成像技术的机会，否则将无法获得这些技术。