Vegetable oils-based microemulsions: Formation, properties, and application for 'ex-situ' soil decontamination

Autor: Marcia Bragato, Omar A. El Seoud, Günter Subklew, M. J. Schwuger
Rok vydání: 2002
Předmět:
Zdroj: Colloid & Polymer Science. 280:973-983
ISSN: 1435-1536
0303-402X
Popis: Methyl esters of coconut oil (CME) and the saturated fraction of palm oil (PME) were prepared from precursor oils by transesterification. Phase diagrams of oil (CME or PME)/water/non-ionic surfactant (Synperonic 91/4) were studied as a function of system composition and temperature. Rheology measurements and X-ray diffraction of the monophases obtained indicated that they are free of cubic liquid crystals. Quasi-elastic light scattering and interfacial tensions of these monophases indicated that they are either bi-continuous, or W/O microemulsions, µEs. Both types were used in decontamination of soil impregnated with polycyclic aromatic hydrocarbons, PAHs. CME- and PME-based µEs (at 37.5 °C, and 42.5 °C, respectively) were found to be more efficient decontaminators than hot toluene. This is attributed to desorption of the contaminants by the µE, followed by their solubilization. The surface charge density of the soil (an indicator of its bioavailability) increased by a factor of 1.6 and 1.8 after decontamination by CME- and PME-based µEs, respectively.
Databáze: OpenAIRE