New Electrochemical Processes for In Situ Soil Decontamination

需要新的就地土壤处理方法来修复被有毒金属污染的土壤。电动力学是一种原位土壤修复技术，它通过在插入土壤中的电极之间施加电场来传输污染物。该方法不涉及挖掘或异地运输污染物质，作为一种补救方法，应该非常为邻近社区的公众所接受。然而，在这项技术被认为是一种有效的土壤去污手段之前，还有相当多的技术问题需要克服。第一个问题是，在电动过程中，负极(即阴极)周围的土壤pH值上升，导致污染物的传输下降，驱动过程所需的能量增加。第二个问题是如何实现污染物在土壤中的有效迁移。这项提案描述了为证明两项电化学创新的可行性而进行的研究，当这两项创新一起应用时，将消除阻碍有效利用电动处理进行土壤修复的重要技术障碍。这些创新将防止阴极处的高pH值，并将为实现污染物在土壤中的快速迁移提供一种全新的机制。第一阶段的实验将使用受重金属污染的天然土壤进行实验室规模的系统。

New in situ soil treatments are needed to remediate soil contaminated with toxic metals. Electrokinetics is an in situ soil remediation technique that involves the transport of contaminants by applying an electric field between electrodes inserted in soil. The method involves no excavation or off-site transportation of contaminated material, and, should be very acceptable to the public in adjacent communities as a remediation method. However, there are considerable technical problems to be overcome before this technique can be considered as an effective means of soil decontamination. The first problem is that during electrokinetic processing the soil pH around the negative electrode (i.e., cathode) rises causing the transport of contaminants to drop and the energy required to drive the process to increase. A second problem is how to achieve efficient contaminant migration through the soil. This proposal describes research to demonstrate the feasibility of two electrochemical innovations that when applied together will eliminate important technical barriers preventing the efficient use of electrokinetic processing for soil remediation. These innovations will prevent high pH at the cathode and will provide a fundamentally new mechanism for achieving rapid contaminant migration in soil. Phase I experiments will be carried out using bench scale systems with natural soils contaminated with heavy metals.