SBIR Phase II: A New Technology for the Formation of Impermeable and Reactive Subsurface Barriers

这个小企业创新研究（SBIR）第二阶段项目描述了一种新方法的开发，用于在土壤中原位形成不可渗透和/或反应性屏障，用于环境清理技术和地球物理工程的潜在应用。在土壤中放置这种屏障以及形成水平或垂直防渗屏障是通过压力注入进行的，这受到短灌浆渗透距离和浅注入深度的限制。 所提出的方法在第一阶段成功地测试了反应性，可渗透的零价铁屏障和不可渗透的水泥屏障的形成。它提供了对土壤条件的简单控制以及试剂的分布，以通过胶凝和/或聚合来控制屏障渗透性。它可以应用于低或高渗透性的饱和土壤中，其中注射灌浆是无效的。第二阶段将集中在控制胶体颗粒传输过程的参数优化上 通过土壤和在土壤中形成不透水和反应性屏障的现场演示。 防渗屏障的初期市场将包括泄漏垃圾填埋场的粘土衬垫的维修和维护、土壤遏制、水下建筑物和建筑物下方建筑物的加固和改进。由零价铁或微生物组成的反应墙将在工业和军事场所的污染地下水和土壤的处理中找到应用。美国环保署估计，使用原位形成的“反应墙”，其中氯化溶剂在原位从有毒物质转化为良性物质，可以节省10亿美元的污染场地清理费用。

This Small Business Innovation Research(SBIR) Phase II project describes development of a new method for the in situ formation of impermeable and/or reactive barriers in soil for potential applications in environmental cleanup technologies and geophysical engineering. The placement of such barriers in soil as well as the formation of horizontal or vertical impermeable barriers is performed by pressure injection, which is limited by short grout permeation distances and shallow injection depth. The proposed method was successfully tested in Phase I for the formation of reactive, permeable zero-valent iron barriers and impermeable cementitious barriers. It provides an easy control of soil conditions as well as a distribution of the reagents to control the barrier permeability through gelling and/or polymerization. It can be applied in saturated soils of low or high hydraulic permeability where injection grouting is not efficient. Phase II will focus on the optimization of the parameters governing the process of controlled transport of colloidal particles through the soil and on-the-field demonstration of the formation of both the impermeable and reactive barriers in soil. Initial markets for the impermeable barriers will include repair and maintenance of clay liners in leaking landfills, soil containment, consolidation and improvement in under-water-constructions and construction below the buildings. Reactive walls, consisting of zero-valent iron or microorganisms prepared by the proposed method will find applications in treatment of polluted groundwater and soil at both industrial and military sites. The EPA estimates the use of in situ formation of `reactive walls` in which chlorinated solvents are converted from toxic to benign substances in situ, could save $ 1 billion in cleanup of contaminated sites.