Soil Clean-Up by Surfactant Washing. I. Laboratory Results and Mathematical Modeling

The removal of weathered-in PCBs from clayey soil by surfactant washing is demonstrated at bench scale. Spent surfactant solution was treated for recycle at bench scale by countercurrent liquid-liquid extraction for the removal of nonvolatile contaminants, and by thin film aeration in packed columns for removal of volatile organics. A correlation of micelle/water partition coefficients with octanol/ water partition coefficients reported earlier by Valsaraj et al. is extended to several additional compounds. Mathematical models for batch–batch, batch–continuous flow, and countercurrent flow surfactant soil washing are described, and the effects of the model parameters are discussed.