Mobilization of Residual NAPL by Seismic Waves

项目摘要：利用地震波动员非水相液体（NAPL）传统的泵送处理技术在清除非水相液体（NAPL）污染的含水层中已经被证明是无效的。一种可能的方法是利用地震波来加强对萘普酸污染含水层的修复。然而，人们对导致动员的机制知之甚少。我们假设可以通过利用毛细管诱导共振来优化被困NAPL团的动员。我们将进行实验，可视化多孔介质中NAPL斑点对振荡流的响应，振荡流是地震波的一个组成部分。周围水相中恒定的背景流将确保被动员的团块向期望的方向移动，从而模拟泵-处理和地震波的联合作用。光学折射率匹配将允许不受干扰地观察流动池中的流体。平面激光片的照明和高速摄影将解决一个激励周期内的运动。斑点将被激发(1)在它们的共振频率上，以加强对过程的理解；(2)以适当参数化的频率扫描的形式，以解释斑点在穿过孔隙空间时改变其共振频率的事实。将建立一个晶格-玻尔兹曼（LB）模型，用于指导实验设计并作为模拟试验台。在界面激发过程中形成小的、可移动的液滴的重要性也将被测量和评估。捕获团的共振频率和动员它们所需的强度的相关性将从物理实验和LB模拟中推断出来。我们的研究可以提高地下水对NAPL污染的修复技术和利用地震波的提高采油方案的效率。我们将大致阐明振荡流动如何影响多孔介质中非混相流体的分布。所提出的研究也将有助于理解振荡流动对非混相流体之间传质（溶解）的影响。此外，NAPL blob共振可以用于监测地下水修复过程中NAPL池的萎缩，甚至可以用于定位NAPL池。该项目将为一名博士生提供研究机会。此外，该项目将丰富巴尔的摩市社区学校的K-12教育。该博士生将开发一个地下水污染教学模块。

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.