Physicochemical Aspects of the Application of Surfactants and Biosurfactants in Soil Remediation

Due to their potent solubilizing and emulsifying properties, synthetic surfactants and biosurfactants can be used for removing hydrophobic pollutants from soil. In this work, the wetting properties, emulsification and micellar solubilization of nonionic surfactants Rokanol L10, Triton X-100 and biosurfactant JBR 425 have been investigated. As hydrophobic model pollutants, tetrachloroethylene (PCE) and o-dichlorobenzene (DCB) were chosen. In the wetting study, no visible effect of the type of surfactant was observed, while there were differences for substrates (tetrachloroethylene or dichlorobenzene). Emulsion stability increases with the increase of surfactant concentration. Emulsions stabilized by Triton X-100 were the most stable. In emulsions prepared with biosurfactant, destabilization occurred earlier than in emulsions with nonionic surfactants. Solubilization of tetrachloroethylene and dichlorobenzene was more effective in solutions of biosurfactant JBR 425 than in solutions of nonionic surfactants. A significant increase of solubilization efficiency for JBR concentrations >15 g/dm³ was noted.