INFLUENCE OF ALCOHOL COSURFACTANTS ON SURFACTANT-ENHANCED FLUSHING OF DIESEL-CONTAMINATED SOIL

ABSTRACT

The effects of medium-chain alcohols on the surfactant-enhanced diesel removal from contaminated sandy soil were investigated. The mixture of Tween 80, which has a double bond in its hydrophobic structure, and hexanol showed the best performance of diesel removal among the combinations of surfactants (Tween 20, Tween 60, and Tween 80) and alcohols (n-butanol, n-pentanol, and n-hexanol) used in this study. The efficiency of diesel flushing increased as the alkyl-chain length of the alcohol and the alcohol fraction in the flushing solution increased. Meanwhile, the removal rate was reduced when the surfactant concentration was too high most likely due to the surfactant aggregation or emulsion formation. A pulsed pumping of flushing solution was not beneficial for improving the removal rate under the experimental conditions described in this study.

Keywords:

• Diesel
• Surfactant-enhanced flushing
• Cosurfactants
• Medium-chain alcohols

ACKNOWLEDGEMENTS

This research was financially supported by RRC program of KOSEF. J. Kim is thankful for the scholarship from BK21 project of MOST of Korea.