Abstract

In soils rich with humus, natural organic matter, and clayey fractions, the partition of hydrophobic organic compounds (HOCs) to the solid phase is much higher than to the aqueous phase. This fact can be related to their sorption on organic fraction of soil, and their higher affinity to the clayey material. Cleanup of such contaminated sites using conventional methods such as pump-and-treat or excavation and further thermal destruction can be lengthy, expensive and in some cases ineffective. Electrokinetics (EK), which is an emerging technology due to its applicability in low permeable soils (clays), seems to be a promising methodology for solving the above mentioned problems. EK is associated with applying a DC current between electrodes inserted into contaminated soil to promote a movement of species into both perforated electrodes, and further extraction of contaminants through these electrodes. However several works have shown some limitations in its use. The presented work is a combined effort of developing an improved EK system being able to apply surfactants to HOC-contaminated clayey soils. This work was concentrated on the design, which could be applied in natural conditions and would eliminate the development of a high pH zone in the cathode area, avoid precipitation and decrease the electrolysis of electrodes.