Remediation of Contaminated Subsurface Using Nanoscale Iron Particles

本研究的目的是研究纳米零价铁（nZVI）颗粒在不同地质介质中的传输和反应性，然后确定有前途的策略，提高nZVI颗粒在不同地下条件下的传输。 我们的假设是：（1）由于聚集，nZVI粒子只能在地下传输到有限的距离;（2）增强策略，如使用分散剂和加压系统，有可能增强nZVI粒子在地下的传输。 该研究将包括进行（1）实验室规模的柱（1-D）实验，以确定运输的nZVI颗粒在不同级配的土壤没有和增强策略，和（2）实验室规模的坦克（3-D）实验，以确定运输的nZVI颗粒在均匀和非均匀的土壤在柱实验确定的最佳条件下。 不同的土壤类型和商业nZVI颗粒将被表征并用于实验。 将通过使用新型分散剂、加压系统以及同时使用分散剂加压系统来实现强化处理。 商业nZVI粒子具有磁性，因此，实时传输的nZVI粒子在多孔介质中将使用电磁敏感度传感器系统进行监测。 将进行罐（3-D）实验，以评估土壤异质性对nZVI颗粒运输的影响。 将在被氯化有机化合物污染的土壤中运输之前和之后对nZVI颗粒的反应性进行量化。 还将使用SEM和TEM图像确定nZVI颗粒的形态变化。将进行初步的数学建模，以预测在实验室和模拟现场条件下多孔介质中nZVI颗粒的运输。 该研究将支持一名博士研究生，培养一名本科生，并提供一个机会，以获得新兴和创新的研究经验，以及接受对他们的职业生涯辅导。 用于研究的设备，特别是物理柱和坦克模拟模型，将作为本科生和研究生课堂教学的演示工具。 研究成果将用于开发新的教学模块“铁纳米颗粒与环境”，并将纳入不同的地质环境课程。 研究结果将通过网站以及通过发表期刊论文和会议/研讨会演讲传播。 将组织一个研讨会和几个开放日和布朗袋会议，以及时反馈行业和监管机构对研究方法和结果。通过这种交流，执业工程师和监管机构可以利用研究结果来了解纳米铁颗粒在污染场地（包括棕地）有效修复中的潜在用途，从而保护公众健康和环境。

The objective of this research is to investigate transport and reactivity of nanoscale zero valent iron (nZVI) particles in different geologic media, and then identify promising strategies for the enhancement of transport of nZVI particles under different subsurface conditions. Our hypotheses are that: (1) as a result of aggregation, nZVI particles can be transported only to limited distances in subsurface; and (2) enhancement strategies such as use of dispersants and pressurized system have potential to enhance transport of nZVI particles in subsurface. The research will include conducting (1) bench-scale column (1-D) experiments to determine transport of nZVI particles in different gradation soils without and with enhancement strategies, and (2) bench-scale tank (3-D) experiments to determine transport of nZVI particles in homogeneous and heterogeneous soils under the optimal conditions determined from the column experiments. Different soil types and commercial nZVI particles will be characterized and used for the experiments. Enhanced treatments will be achieved through the use of novel dispersants, pressurized system, and the simultaneous use of dispersant-pressurized systems. The commercial nZVI particles possess magnetic properties; therefore, a real-time transport of the nZVI particles in porous media will be monitored using an electromagnetic susceptibility sensor system. Tank (3-D) experiments will be conducted to evaluate the effects of soil heterogeneities on the transport of nZVI particles. The reactivity of nZVI particles will be quantified before and after transport in soil contaminated with chlorinated organic compounds. The changes in morphology of the nZVI particles will also be determined using SEM and TEM images. Preliminary mathematical modeling will be performed to predict the transport of nZVI particles in porous media under laboratory and simulated field conditions. The research will support a doctoral graduate student,, train an undergraduate student, and provide an opportunity to gain emerging and innovative research experience as well as receive mentoring towards their professional careers. Equipment for the research, especially the physical column and tank simulation models, will serve as demonstration tool for classroom instruction on both the undergraduate and graduate levels. The research results will be used to develop new a teaching module "Iron Nanoparticles and the Environment" and it will be incorporated into different geoenvironmental courses. Research results will be disseminated through a website as well as through publication of journal papers and conference/seminar presentations. A workshop and several open houses and brownbag meetings will be organized for timely feedback of industry and regulatory agencies on the research approach and results. Through such communication, practicing engineers and regulatory agencies can utilize the research results to understand the potential use of nanoscale iron particles for efficient remediation of polluted sites (including brownfields), thereby protecting public health and the environment.