EFFECT OF ANIONIC BIOSURFACTANT ON HEXADECANE PARTITIONING IN MULTIPHASE SYSTEMS

The-effectiveness of anionic rhamnolipid biosurfactant and a synthetic anionic surfactant in solubilizing hexadecane in multiphase systems is compared. The partitioning of hexadecane in multiphase systems containing aqueous, organic, and soil phases is examined in the presence of varying concentrations of rhamnolipid or alkyl benzyl sulfonate (ABS) surfactant. Partitioning of the rhamnolipid biosurfactant and the ABS surfactant between each of the phases is also examined. The critical micelle concentration (CMC) of each surfactant and the molar solubilization ratio (MSR) of each surfactant for hexadecane are experimentally determined. The MSR of the rhamnolipid is found to be approximately 20 times greater than the MSR of ABS for hexadecane. Differences in micellar structure between the rhamnolipid biosurfactant and the ABS syntheic surfactant are proposed to account for the increased ability of the rhamnolipid to solubilize hexadecane in the micellar phase.