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

这一小型企业创新研究(SBIR)第二阶段项目描述了一种在土壤中原位形成不透水和/或反应性屏障的新方法的开发，以用于环境清理技术和地球物理工程中的潜在应用。这种屏障在土壤中的放置以及水平或垂直防渗屏障的形成都是通过压力注入完成的，这受到灌浆渗透距离短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、渗透性零价铁屏障和不透水水泥屏障的形成。它提供了对土壤条件的轻松控制以及试剂的分布，以通过凝胶和/或聚合来控制屏障渗透性。适用于注浆效果不佳的低渗透或高渗透饱和土层。第二阶段将侧重于优化控制胶体颗粒在土壤中的传输过程的参数，并现场演示土壤中不渗透和反应性屏障的形成。不透水屏障的初步市场将包括修复和维护渗漏垃圾填埋场的粘土衬里，土壤遏制，加固和改善水下建筑和建筑物下方的建筑。由零价铁或微生物组成的反应性墙将在工业和军事场所的受污染地下水和土壤处理中得到应用。美国环保署估计，在污染场地的清理工作中，使用原位形成的“活性墙”，即氯化溶剂在现场从有毒物质转化为无害物质，可以节省10亿美元。

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.