In Situ Bioremediation of Perchlorate and Nitrate in Vadose Zone Soil using Gaseous Electron Donor Injection Technology (GEDIT)

摘要

Perchlorate is a human health concern because of its ability to inhibit iodide uptake by the thyroid. While extensive research and technology development on the treatment of perchlorate in water has been conducted, limited research and technology development has been focused on perchlorate in soil. Perchlorate contamination in soil is important because it can be a source of groundwater contamination. Currently, available technologies for the treatment of perchlorate in soil require excavation and are not always cost- effective or practical, particularly as the depth of contamination increases. In situ remediation of perchlorate in soil is an alternative, potentially more cost-effective solution. Gaseous electron donor injection technology (GEDIT) (U.S. Patent No. 7,282,149 and patent pending) involves injection of gaseous electron donors (GED) into the soil with the purpose of promoting anaerobic biodegradation of perchlorate to water and chloride ion. This technology can be viewed as bioventing in reverse. Bioventing, a proven bioremediation technology for petroleum hydrocarbons, involves the injection of a gaseous electron acceptor (e.g., oxygen) into the vadose zone resulting in the biodegradation of an electron donor (e.g., hydrocarbons). In the present application, the electron acceptor and donor are reversed with the GED being injected in order to biodegrade the electron acceptor (i.e., perchlorate or nitrate). GEDIT is also applicable to treatment of other Department of Defense (DoD) and Department of Energy related contaminants such as hexavalent chromium, uranium, technetium, chlorinated volatile organic compounds (VOC), and highly energetic compounds including trinitrotoluene (TNT), royal demolition explosive (RDX), and high melting explosive (HMX).