ABSTRACT
This chapter is concerned with important properties of microemulsions regarding their use as extraction media in the soil remediation concept. It presents some of the essential results on the phase behavior of ternary and pseudo-ternary mixtures of water, nonionic surfactants and rapeseed oil (RSO), rape oil methyl ester, or castor oil. To solubilize RSO, a mixture of two nonionic surfactants of technical grade was used leading to a quaternary system. The investigations show that the formation of bicontinuous microemulsions with native oils like RSO is possible at slightly elevated temperatures. Appropriate microemulsions consisting of biodegradable components were found for application in soil remediation. These microemulsions are excellent extraction media for removing pyrene as a representative contaminant from the soil. For the determination of the distribution of pyrene between the polar and the nonpolar phase, the same procedures were chosen as described under "phase diagrams".
