Evaluating vertical transverse dispersion at sand/clay interfaces in groundwater systems

地下水污染是对人类和生态系统健康的严重威胁。污染场地的修复通常具有挑战性，因为大多数场地是异质的，污染物被隔离在低渗透性区域，如这些场地的粘土透镜。污染物在一种被称为反向扩散的过程中慢慢地扩散出这些区域。受污染地点的反向扩散可能会使补救时间延长数十年至数百年。粘土和淤泥透镜体的反向扩散速率会受到粘土和淤泥与更具渗透性材料交界处的横向垂直弥散的极大影响。界面处的横向垂直弥散过程还没有被很好地理解。该项目的目标是通过对含有粘土透镜的系统中污染物传输的二维实验室尺度研究，改进对横向垂直扩散的理解。试验台规模研究的结果将用于开发 含粘土透镜的地下水系统中污染物运移预测的改进模型。

Groundwater contamination is a serious threat to human and ecosystem health. Remediation of contaminated sites is often challenging because most sites are heterogeneous and contaminants are sequestered in low permeability zones such as clay lenses at these sites. Contaminants slowly diffuse out of these zones in a process referred to as back-diffusion. Back-diffusion at contaminated sites may increase remediation timeframe by decades to centuries. Back-diffusion rates from clay and silt lenses can be greatly impacted by transverse vertical dispersion at the the clay and silt interfaces with more permeable materials. The process of transverse vertical dispersion at interfaces is not well understood. The objective of this project is to develop improved understanding of transverse vertical dispersion through two-dimensional bench scale studies of contaminant transport in systems containing clay lenses. The results of the bench scale studies will be used to develop improved models for predicting contaminant transport in groundwater systems containing clay lenses.