MICELLAR SOLUBILIZATION OF POLYNUCLEAR AROMATIC-HYDROCARBONS IN COAL TAR-CONTAMINATED SOILS

Solubilization of PAHs from a coal tar-contaminated soil obtained from a manufactured gas plant (MGP) site was evaluated using nonionic poly oxyethylene surfactants at dosages greater than cmc. Up to 25% of Soxh let-extractable PAHs could be solubilized at surfactant loadings of 0. 3 g/g of soil in 16 days in completely stirred batch reactors. Longer periods were required to reach equilibrium at higher surfactant dosage s. Raoult's law satisfactorily described the partitioning of constitue nt PAHs between the weathered coal tar and the micellar solution. An e quilibrium model was developed to predict the solubilization of PAHs f rom coat tar-contaminated soils for given properties of the soil, surf actant, and component PAHs. The model predicted solubilization of cons tituent PAHs reasonably well at low surfactant dosages. At extremely h igh surfactant dosages, the model failed to reliably predict solubiliz ation. Presumably, mass transfer limitations prevented attainment of e quilibrium during the duration (380 h) of solubilization experiments.