MICROALGAL LIPIDS AS BIOSURFACTANTS IN A BIOREMEDIATION OF DIESEL AND BIODIESEL IN SOIL

Abstract

The concern with the environment has been growing in last years. These contexts include the search for alternatives to low the generation of pollutants, as well as decontamination of sites contaminated with hazardous wastes that may be toxic to the environment and the population as a whole. The aim of this work was the use of microalgal lipids as biosurfactants in the decontamination of soil contaminated with diesel and biodiesel, compared with natural attenuation. Lipids were extracted of the Spirulina platensis biomass and added to diesel or biodiesel contaminated soils. The biodegradation was accompanied by determination of oil and grease and microbial activity by the technique of CO2 evolution. The microalgal lipids demonstrated its potential in the bioremediation of oil residues, since there was obtained 81.9% and 81.7% of biodiesel and diesel biodegradation respectively, greater than the values obtained in natural attenuation, of 54.36% and 30.09% with diesel or biodiesel respectively, at 60 days of bioremediation. The evolution of CO2 also showed high results of accumulated CO2 in the tests added of biosurfactant. In the assay of biodiesel added of biosurfactant, cumulative CO2 was 1341.65 mg at 60 days, compared to 775.3 mg of CO2 in assay realized with biosurfactant and diesel, while in trials with natural attenuation, the evolution of CO2 was 184.51 mg and 246.80 mg for diesel to biodiesel. Keywords: Biodegradation, Spirulina platensis, lipids; CO2 evolution.