Collaborative Research: Innovative Injection and Extraction Schemes to Enhance Mixing in Aquifers for Improved In Situ Remediation

对受污染的地下水进行就地补救往往需要向含水层中注入处理溶液，以促进污染物的降解反应。原位修复的一个重大挑战是在多孔介质中混合的固有困难。 如果处理溶液和受污染的地下水不充分混合，就无法发生实现就地补救所需的降解反应。本项目检验的假设是，污染物羽流附近安装的威尔斯井的战略性操作可以加强受污染地下水的就地补救，其目标是促进处理溶液和受污染地下水之间界面的拉伸和折叠，从而增加发生降解反应的机会。 该项目涉及数值模拟和优化，以调查井作业策略，将最大限度地减少污染物。 优化考虑了威尔斯的数量、它们的位置以及每个井提取或注入流体的速率作为时间的函数。 研究调查溶解的污染物和那些吸附到含水层固体在均匀和非均匀含水层使用一套现代地下水模型。井的位置，抽水计划和含水层属性的相互作用的特点是一系列的无量纲的数字，可用于修复系统的设计。污染威胁着重要的地下水资源，而这些地下水资源为许多市政供水设施和家庭用水威尔斯提供水源。 在美国，已经有数十亿美元用于修复受污染的地下水，然而，在许多地方，补救工作没有达到清理目标。本项目研究了一种通过注入和抽取威尔斯井（一种现有技术）以一种新的方式改善污染地下水净化的方法，以促进原位地下水修复。该项目提供了一个初步的理论探索，这些新的方法，将与现有的方法相比，污染物降解的完整性，成本和地下水水质改善的增强混合。此外，这项研究提供了一个新的建立混沌理论和地下水流之间的联系，将导致地下污染物输运的新见解。该项目还将创建一个物理演示装置和教育模块，通过允许用户通过注入和抽取来操纵羽流，使大学预科生学习地下水。完成后，该设备将通过在博尔德的科罗拉多大学的一个既定的教学实验室收集。

In situ remediation of contaminated groundwater often requires the introduction of a treatment solution into the aquifer in order to promote contaminant degradation reactions. A significant challenge for in situ remediation is the inherent difficulty of mixing in porous media. Without sufficient mixing of the treatment solution and the contaminated groundwater, the degradation reactions required to achieve in situ remediation cannot occur. This project tests the hypothesis that in situ remediation of contaminated groundwater can be enhanced through strategic operation of wells, installed near the contaminant plume, whose goal is to promote stretching and folding of the interface between the treatment solution and contaminated groundwater, thereby increasing the opportunity for degradation reactions to occur. The project involves numerical simulation and optimization to investigate well operation strategies that will maximize contaminant degradation. The optimization considers the number of wells, their locations and the rates at which each well extracts or injects fluid as a function of time. The study investigates both dissolved contaminants and those sorbed to the aquifer solids in homogeneous and heterogeneous aquifers using a suite of modern groundwater models. The interplay of the well placement, pumping schemes, and aquifer properties will be characterized by a series of dimensionless numbers that can be used for remediation system design. Contamination threatens important groundwater resources that provide the water supply for numerous municipal water utilities and domestic water wells. Already, billions of dollars have been spent on remediation of contaminated groundwater in the U.S., and yet at many locations, the remediation efforts have not met cleanup targets. This project investigates a method for improving the cleanup of contaminated groundwater by using injection and extraction wells (an existing technology) in a novel way to promote in situ groundwater remediation. This project provides an initial theoretical exploration of the enhanced mixing achievable by these novel methods that will be compared with existing methods in terms of contaminant degradation completeness, cost, and groundwater quality improvement. Additionally, this study provides a new link between established chaos theory and groundwater flow that will lead to new insights into subsurface contaminant transport. The project will also create a physical demonstration apparatus and education module that will be used to engage pre-college students in learning about groundwater by allowing users to manipulate plumes by injection and extraction. After completion, the apparatus will be available through an established teaching laboratory collection at the University of Colorado at Boulder.