Potential of surfactant foam stabilized by Ethylene glycol and Allyl alcohol for the remediation of diesel contaminated soil

Abstract

Refined petroleum products like diesel oil enters the soil as a result of damaged pipelines and storage tanks. This constitutes a major hazard for the environment as it leads to problems associated with soil contamination. The application and impact of surfactant foam, stabilized by the use of biodegradable additives — Ethylene glycol and Allyl alcohol, for treating diesel contaminated soil is a novel concept and has not been reported so far. The aim of the current work was thus to check the diesel contaminated soil remediation potential with the usage of surfactant foam, stabilized by Ethylene glycol and Allyl alcohol. To better understand the foam properties, experiments were performed by mixing the appropriate quantities of additives and two popular surfactants — Sodium n-dodecyl sulfate (SDS), Tween 80, using Dynamic Foam Analyzer (Kruss, Germany). The stable foams produced were then utilized to treat the diesel contaminated soil and interesting results were obtained. The foam stabilized by surfactant SDS in combination with 0.3 weight% Allyl alcohol showed maximum diesel oil removal efficiency of 62%. Also, surfactant Tween 80 with 0.3 weight% of Allyl alcohol produced the most stable foam with a half-life of 18 mins and resulted in maximum diesel removal efficiency of 71%. SDS, Tween 80 foams stabilized by 0.3 weight% Ethylene glycol however produced much lower diesel removal efficiency. The mechanism of surfactant adsorption onto soil was studied. The surface tension analysis, using the different additives — Ethylene glycol, Allyl alcohol with the surfactant solutions, were performed to check on the mobilization of diesel oil from the soil.