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以以下形式释放到环境中： 非水相液体（NAPL）通过表面溢出，储罐 危险废物填埋场的泄漏或浸出。存在和 NAPL 在地下系统中的行为尚未得到充分考虑 用于之前的含水层建模工作。这是两个同伴之一 密歇根大学将开展项目来解决这个问题 不足。该项目将特别关注大规模转移 化学品从有机液相到水相和气相。 将进行实验来检查 VOC 传质 填充塔中残余饱和的不混溶有机液体 多孔介质。液-液和液-汽相间转移 过程将用适当的传质来描述 系数和驱动力。特征之间的相关性 多孔介质（例如粒度分布）和传质 将建立系数。流量、配置的变化 不混溶相、初始润湿液和柱长的影响 允许量化传质速率。广义的 描述传质和传输动力学的数学模型 通过多孔介质将被写入以帮助分析 从这些实验中获得的数据。该模型将包括一个质量 非水液相的平衡。局部平衡分配 和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。从当地出发 将使用几种现象学质量传递来模拟平衡 与不混溶相的性质相关的表达式 多孔介质。基于此分析，专门配置的质量 最能表征观察到的数据的传输模型将是 被识别并合并为计算机模拟器中的“子模型” 正在配套项目中开发。