USAGE OF BIOSURFACTANTS EXTRACTED FROM CORN STEEP LIQUOR TO ELIMINATE BURNED ENGINE OIL ON SANDY SOIL

Abstract

The interest in biosurfactants for the removal of hydrophobic contaminants on contaminated soils is increasing. The objective of this study was to evaluate the decontamination process in sandy soils polluted with burned car engine oil, using a natural detergent, extracted from a residual stream from the corn milling industry named ``corn steep liquor{''}. The emulsifier and interactive capacity of the biosurfactant with the burnt oil was first evaluated. Then, discontinuous extraction experiments were carried out in batch by triplicate on a mixture of 5 g of sandy soil containing 50,000 ppm burned oil, using several formulated cleaner solutions with the biosurfactant, above and below its critical micelle concentration (CMC), using solid/liquid relations between 1/10 and 1/30 (w:v). Results show that the 1/20 solid/liquid ratio (w: v) was the most suitable for the washings. After 6 h in contact, the cleaning process showed good results. The high biodegradability of the biosurfactant extract and the relatively low treatment times allow us to suggest its use in in-situ decontamination processes of petroleum-based oils contaminated areas.