(596c) Use Of The Bicontinuous L3 Phase As An Extractant In Extraction Of Hydrophobic Organic Compounds From Aqueous Solutions

Application of L₃ sponge phase as an extractant in extraction of hydrophobic organic compounds from aqueous solution were studied systematically at 25°C with three nonionic surfactants, Tergitol 15-S-5, LE-203 (C₁₂E₃) and Brij 30 (C₁₂E₄). The transition temperatures of the coexisting W+L₃ phases of these surfactants could be regulated with addition of proper salting-out electrolytes and short-chain alcohols. The low viscosities of these L₃-phase extractants, ranging from 10 to 40 mPa•s, make it not difficult for separation of these extract-containing L₃ phases from the coexisting water (W) phases. Compared to the conventional cloud-point extraction techniques, a relatively larger preconcentration factor with satisfactory recovery efficiency of PAHs are achieved in such L₃-phase extraction procedure. In general, a higher preconcentration factor is attained with a decrease in surfactant concentration and/or with increasing concentrations of additives employed in this work.