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

这个小型企业创新研究（SBIR）二期项目描述了一种新的方法，用于在土壤中原位形成不渗透和/或反应性屏障，在环境清理技术和地球物理工程中有潜在的应用。这种屏障在土壤中的放置以及水平或垂直不透水屏障的形成是通过压力注入来完成的，这受到灌浆渗透距离短和注入深度浅的限制。该方法在第一阶段成功测试了反应性、渗透性零价铁屏障和不渗透性胶凝屏障的形成。它提供了一个容易控制的土壤条件，以及试剂的分布，以控制通过凝胶和/或聚合屏障的渗透性。它适用于水力渗透性低或高的饱和土，注浆效果不佳。第二阶段将侧重于优化控制胶体颗粒通过土壤的受控运输过程的参数，并在现场演示土壤中不透水和反应性屏障的形成。不透水屏障的初期市场将包括修复和维护渗漏的堆填区粘土衬垫、土壤密封、巩固和改善水下建筑和建筑物下面的建筑。由零价铁或微生物组成的活性墙将在工业和军事场所处理受污染的地下水和土壤中得到应用。美国环保署估计，使用原位形成的“反应墙”，将氯化溶剂从有毒物质就地转化为良性物质，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.