Investigation of Cyclodextrin-Enhanced Electrokinetic Soil Remediation. Fate and Transport of Nitroaromatic Contaminants and Cyclodextrin Amendments in Expansive Clays

摘要

Nitroaromatic-based compounds can pose a serious threat to ecosystems and human health. These compounds, which have been used in munitions and pesticides, are present in soil and groundwater at military installations and other sites. The presence of these contaminants in clayey soils poses a difficult and potentially costly remediation problem. The low hydraulic conductivity of these soils prohibits the use of conventional pump-and-treat remediation techniques, and high energy costs make the process of excavating and thermally treating the soil highly inefficient and damaging to the environment. For these reasons, much research has been done to advance the field of electrokinetic remediation as a viable cleanup technique. Although some studies have reported that organic molecules can be removed from clayey soils by electro-osmosis alone using a purging solution, the addition of amendments to the solution has increased removal efficiencies. The objective of this research was to advance the state of knowledge on a novel technique for cost-effective remediation of nitroaromatic compounds using cyclodextrin molecules as solubilizing agents and electrokinetically transporting them through the contaminated zone. The results provided direct evidence that it is possible to remove nitrobenzene and 2,4-DNT from expansive montmorillonite clay using electro-osmosis both with and without cyclodextrin amendments.