MASS TRANSFER REACTIONS BETWEEN VOCS, AQUEOUS & VAPOR PHASES IN THE SUBSURFACE

VOC、水之间的传质反应

• 批准号: 3876771
• 负责人: LINDA M ABRIOLA
• 金额: --
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3876771
• 关键词: computer simulation; environmental contamination; environmental engineering; fluidity; hydropathy; mathematical model; nonwater solvent; organic chemicals; phase change; soil pollution; water solution

Volatile organic chemicals are commonly released to the environment as non-aqueous phase liquids(NAPL) 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. This is one of two companion projects to be conducted at the University of Michigan to address that deficiency. This project will focus specifically on the mass transfer of chemicals from organic liquid phases to aqueous and vapor phases. Experiments will be conducted to examine VOC mass transfer from immiscible organic liquids at residual saturation in packed columns of porous media. Liquid-liquid and liquid-vapor interphase transfer processes will be described in terms of appropriate mass transfer coefficients and driving forces. Correlations between the characteristics of the porous media (e.g., grain size distribution) and the mass transfer coefficient will be established. Variations in flow rate, configuration of the immiscible phase, initial wetting fluid, and column length will permit quantification of rates of mass transfer. A generalized mathematical model describing the kinetics of mass transfer and transport through the porous media will be written to aid in the analysis of the data obtained from these experiments. The model will include a mass balance for the non-aqueous liquid phase. Local equilibrium partitioning and kinetic mass transfer expressions will be incorporated as options in the model to describe the interphase mass exchange. Departures from local equilibrium will be modeled using several phenomenological mass transfer expressions related to the properties of the immiscible phase and the porous media. Based on this analysis, that specifically configured mass transfer model which most closely characterizes the observed data will be identified and incorporated as a "sub-model" in the computer simulator being developed in the companion project.

挥发性有机化学物质通常被释放到环境中 非水相液体（NAPL）通过表面溢出，储罐 泄漏或从危险废物垃圾填埋场中浸出。存在和 NAPL在地下系统中的行为尚未充分考虑 在先前的含水层建模工作中。这是两个同伴之一 要在密歇根大学进行的项目来解决 不足。该项目将专门关注 从有机液相到水性和蒸气相的化学物质。 将进行实验以检查从 在堆积柱中残留饱和的不可分用的有机液体 多孔媒体。液态液体和液相转移 过程将以适当的传态来描述 系数和驱动力。特征之间的相关性 多孔介质（例如晶粒尺寸分布）和传质 系数将建立。流速，配置的变化 不混溶的相位，初始润湿流体和圆柱长度将 允许定量传质率。广义 描述传质和运输动力学的数学模型 通过多孔媒体将被编写以帮助分析 从这些实验获得的数据。该模型将包括一个质量 非水液相的平衡。局部平衡分区 动力学传质表达式将作为选项纳入 描述相间质量交换的模型。偏离当地 平衡将使用几种现象学传质进行建模 与不混溶阶段的性质和 多孔媒体。基于此分析，专门配置了质量 最接近观察到的数据的传输模型将是 在计算机模拟器中识别并合并为“子模型” 在同伴项目中开发。