Mobilization of Residual NAPL by Seismic Waves

项目摘要：地震波动员残留的NAPL传统的泵送和处理技术在清理被非水相液体(NAPL)污染的含水层方面已被证明是无效的。加强修复受NAPL污染的含水层的一种可能办法是使用地震波。然而，对导致动员的机制知之甚少。我们假设，通过利用毛细诱导的共振可以优化捕获的NAPL斑点的动员。我们将进行实验，可视化多孔介质中NAPL水滴对振荡流动的响应，振荡流动是地震波的一个组成部分。周围水相中的恒定背景流将确保动员的水滴移动到所需的方向，从而模拟泵送和治疗和地震波的联合作用。光学折射率匹配将允许对流动池中的流体进行不受干扰的观察。用平面激光薄片照明和高速摄影将解决一个激发周期内的运动。斑点将被激发(1)在其共振频率处以增强过程理解，以及(2)以适当参数的频率扫描的形式来考虑斑点在其移动通过孔隙空间时改变其共振频率的事实。将开发一个格子-玻尔兹曼(LB)模型，用于指导实验设计并作为模拟试验台。还将测量和评估界面激发期间形成小的、可移动的液滴的重要性。物理实验和LB模拟将推断出捕获水滴的共振频率和动员它们所需的强度之间的关联。我们的研究可以提高NAPL污染的地下水修复技术和使用地震波的提高采油方案的效率。我们将大体上阐明振荡流动如何影响不混溶流体在多孔介质中的分布。这项研究还将有助于理解振荡流动对不相容流体之间传质(溶解)的影响。此外，可以利用NAPL斑点共振来监测地下水修复期间NAPL池的萎缩，甚至定位NAPL池。该项目将为一名博士生提供研究机会。此外，该项目还将丰富巴尔的摩市社区学校的K-12教育。这位博士生将开发一个关于地下水污染的教学模块。

Project Abstract: Mobilization of Residual NAPL by Seismic WavesConventional pump-and-treat technologies have proven to be ineffective in cleaning up aquifers that are contaminated by nonaqueous phase liquids (NAPL). One possible approach for enhancing the remediation of NAPL-contaminated aquifers consists of applying seismic waves. Little is known, however, about the mechanism leading to mobilization.We hypothesize that the mobilization of trapped NAPL blobs can be optimized by exploiting capillarity-induced resonance. We will perform experiments that visualize the response of NAPL blobs in porous media to oscillatory flow, which is one component of a seismic wave. Constant background flow in the surrounding aqueous phase will ensure that mobilized blobs are moved into a desired direction and hence simulate the combined action of pump-and-treat and seismic waves. Optical refractive index matching will allow for undisturbed view on the fluids in the flow cells. Illumination with a planar laser sheet and high speed photography will resolve the motion within an excitation cycle. Blobs will be excited (1) at their resonant frequency to enhance process understanding, and (2) in the form of appropriately parameterized frequency sweeps to account for the facts that a blob changes its resonant frequency as it moves through a pore space. A lattice-Boltzmann (LB) model will be developed that is used to guide the design of the experiments and as a simulation test bed. The importance of the formation of small, mobile droplets during excitation of the interfaces will also be measured and evaluated. Correlations for the resonant frequency of trapped blobs and intensities required to mobilize them will be inferred from physical experiments and LB simulations.Our research could improve the efficiency of both groundwater remediation techniques for NAPL contamination and enhanced oil recovery schemes that use seismic waves. We will in general elucidate how oscillatory flows effect the distribution of immiscible fluids in porous media. The proposed research will also help understanding the effects of oscillatory flow on mass transfer (dissolution) between immiscible fluids. Furthermore, NAPL blob resonance could be exploited to monitor the shrinking of a NAPL pool during a groundwater remediation, or even to locate NAPL pools. The project will provide research opportunities for one PhD student. Moreover, the project will enrich K-12 education at Baltimore City Neighborhood Schools. The PhD student will develop a teaching module on groundwater contamination.