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.

有机化学物质以非水相（不混溶）有机液体（NAPLs）的形式存在于许多污染场所的地下，并作为地下水污染的长期来源。这些地点的有效风险评估和补救取决于能否准确表征NAPL和地下水之间组分的传质（NAPL溶解）。在实验室色谱柱上对影响萘酰萘酯溶解的因素进行了详细的研究。然而，NAPLs在孔隙尺度上的基本溶解行为尚不清楚。此外，很少有人研究多孔介质非均质性对NAPL溶解的影响。该研究的总体目标是更好地了解致密非水相、不混溶有机液体（DNAPLs）在地下系统中的溶解行为。具体的