MODELING VOLATILIZATION AND VAPOR TRANSPORT OF CONTAMINANTS IN THE SUBSURFACE

挥发性有机化学品通常被释放到环境中， 非水相液体（NALS）通过表面溢出，储罐 危险废物填埋场的渗漏或沥滤。的存在和 地下系统中非水相液体的行为尚未得到充分考虑 在以前的含水层建模工作。这是两个同伴之一 项目将在密歇根大学进行，以解决这一问题， 缺陷该项目将重点发展和部分 验证能够量化地下 作为一个单独的阶段，NAPL本身的运动以及 NAPL挥发产生的气相。均为非水性 通过对流和扩散进行的整体输送和气相输送将 成为模特。该模型将开发计算效率和 灵活性.将模型扩展到二维域， 多组分有机混合物也包括在该研究计划中。 为了验证建模方法中固有的物理假设， 两种代表性的挥发性有机化合物的行为将是 探讨了这两种化合物的本构参数为： 测量和柱实验将进行比较， 一维模型模拟。在研究的后期， 将进行二维实验室研究，以验证这两个- 三维模型，并探讨使用主动和被动气体采样 技术.关于界面相的模型假设的有效性 质量交换将在同伴研究项目中进行探索， 该伙伴项目的成果将纳入总体 在这个项目中开发的计算机模拟器。

Volatile organic chemicals are commonly released to the environment as nonaqueous phase liquids (NALS) via surface spillage, storage tank leakage, or leaching from hazardous waste landfills. The presence and behavior of NAPL in subsurface systems has not been adequately accounted for in prior aquifer modeling efforts. The is one of two companion projects to be conducted at the University of Michigan to address that deficiency. This project will focus on the development and partial verification of a computer model capable of quantifying the subsurface movement of NAPL itself, as a separate phase, as well as the movement of gas phases which result from volatilization of NAPL. Both non-aqueous bulk transport and vapor phase transport by convection and diffusion will be modeled. The model will be developed for computational efficiency and flexibility. Extensions of the model to two-dimensional domains and multi-component organic mixtures are also included in this research plan. To verify the physical assumptions inherent in the modeling approach, the behavior of two representative volatile organic compounds will be explored. Constitutive parameters for these two compounds will be measured and column experiments will be conducted for comparison with one-dimensional model simulations. In the later stages of the research, two-dimensional laboratory studies will be conducted to verify the two- dimensional model and explore the use of active and passive gas sampling techniques. The validity of the model assumptions concerning interphase mass exchange will be explored in the companion research project, and the results from that companion project will be incorporated into the overall computer simulator developed in this project.