Collaborative Research: Air-Flow Mechanisms During Insitu Air-Sparging Operations

合作研究：原位空气喷射操作期间的气流机制

• 批准号: 0409521
• 负责人: Patricia Culligan
• 金额: $ 13.59万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0409521&HistoricalAwards=false
• 关键词: Collaborative; Research; Air; Flow; Mechanisms

There are over 300 million acres of land in the United States for which underlying groundwater contamination is labeled a serious concern. There are many more acres for which underlying groundwater contamination, although not considered serious, threatens local groundwater quality and environmental health. The current cost of cleaning up contaminated groundwater using existing approaches to remediation is greater than the annual US Gross National Product. Thus, despite recent advances in the design of technologies for the insitu remediation of contaminated groundwater, research is still required that enables these technologies to become more cost effective and efficient. Insitu Air Sparging (IAS) is one remediation technology that has documented success for the cleanup of aquifers contaminated with Volatile Organic Compounds (VOCs), such as petroleum hydrocarbons. In fact, insitu air sparging is now thought to be the most widely used technology in the US for the remediation of hydrocarbon contaminated sites. Despite this, IAS design in practice remains largely empirical and based on information obtained from pilot scale tests involving observations surrounding a single sparge well. The research community has developed predictive models for IAS performance. However, the use of these models for design practice has been limited by their complexity and, more notably, their use of soil parameters that are not typically measured in practice. In addition, many of these models only consider a single sparge point, whereas IAS systems are engineered with multiple sparge points specifically to generate overlapping air-plumes. The proposed work will develop a reliable, and practical, model to predict the air-flow patterns generated by multiplepoint sparging to improve the current design and optimization of IAS systems. The resulting model will be based on combined geo-centrifuge testing and the immersion method to enable direct visualization of air-plume development under capillary and fluid pressures that mimicked those in the field. Previous work resulted in an axi-symmetrical model that can predict air-flow patterns above a single sparge point in a homogeneous medium based upon input parameters typically measured in practice. The extension of the original model will enable predictions of three-dimensional air plume development above multiple sparge points in a heterogeneous medium. The researchers will validate the model using field data from pilot scale tests, and actual IAS operations. This work will have considerable broad impact on the future design of IAS systems. Improvements in the effective application of remediation technologies, including IAS, will have direct benefit on future public and environmental health. The release of prior contaminated land for re-use also provides economic and social benefit to the country. The results will be disseminated through professional development seminars that we will run in Year 3 of the project. To encourage attendance by those in practice, we will limit each seminar to one day. The seminars will be run at cost. They will discuss the factors influencing air-flow during IAS, IAS design considerations, pilot testing, and monitoring requirements. They will also introduce the new model and provide guidance on its use in practice.

美国有超过3亿英亩的土地，地下水污染是一个严重的问题。还有更多的土地受到地下水污染，尽管不被认为是严重的，但威胁到当地地下水的质量和环境健康。目前使用现有补救方法清理受污染地下水的成本高于美国的年度国民生产总值。因此，尽管最近在设计受污染地下水就地补救技术方面取得了进展，但仍需要进行研究，使这些技术更具成本效益和效率。原位空气喷射（IAS）是一种修复技术，已记录了被挥发性有机化合物（VOC）污染的含水层（如石油烃）的成功清理。事实上，原位空气喷射现在被认为是美国用于修复烃污染场地的最广泛使用的技术。尽管如此，IAS设计在实践中仍然主要是经验性的，并基于从中试规模试验中获得的信息，包括对单个喷射井的观察。研究界已经为国际会计准则的业绩制定了预测模型。然而，使用这些模型的设计实践受到其复杂性的限制，更值得注意的是，它们使用的土壤参数通常在实践中不测量。此外，这些模型中的许多模型仅考虑单个喷射点，而IAS系统设计有多个喷射点，专门用于产生重叠的空气羽流。建议的工作将开发一个可靠的，实用的，模型来预测多点喷射产生的气流模式，以改善目前的设计和优化IAS系统。 由此产生的模型将基于地质离心试验和浸没方法，以便能够直接可视化在毛细管和流体压力下的空气羽流发展，这些压力模拟了现场的情况。以前的工作产生了一个轴对称模型，可以预测空气流模式以上的一个单一的喷射点在均匀介质中的输入参数通常在实践中测量的基础上。原始模型的扩展将能够预测三维空气羽流发展以上的多个喷射点在非均匀介质。研究人员将使用中试规模测试和实际IAS操作的现场数据来验证该模型。这项工作将对国际会计准则系统的未来设计产生相当广泛的影响。改进补救技术的有效应用，包括国际会计准则，将对未来的公众和环境健康产生直接的好处。释放以前受污染的土地供重新使用也为该国带来了经济和社会效益。研究结果将通过我们将在项目第三年举办的专业发展研讨会进行传播。为了鼓励那些在实践中的出席，我们将限制每个研讨会一天。研讨会将按成本收费。他们将讨论IAS期间影响气流的因素，IAS设计考虑因素，试点测试和监控要求。他们还将介绍新的模式，并就其在实践中的使用提供指导。