%0 Journal Article
%T Application of a Yeast Biosurfactant in the Removal of Heavy Metals and Hydrophobic Contaminant in a Soil Used as Slurry Barrier
%A R. D. Rufino
%A G. I. B. Rodrigues
%A G. M. Campos-Takaki
%A L. A. Sarubbo
%A S. R. M. Ferreira
%J Applied and Environmental Soil Science
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/939648
%X This work describes the application of a yeast biosurfactant in the removal of heavy metals and petroleum derivate in a soil used as slurry barrier using a triaxial permeability apparatus. Test specimens were prepared with soil and contaminants for percolation of the biosurfactant. The hydraulic conductivity measured along percolation of the fluids showed that the biosurfactant reduced significantly the soil permeability, demonstrating its applicability as an additive in reactive barriers. The crude biosurfactant removed around 96% Zn and Cu and reduced the concentrations of Pb, Cd, and Fe from the test specimen. The biosurfactant removed 20% of the waste oil using the permeability apparatus. The results show that the biosurfactant can be applied in new technologies where the removal of heavy metals and petroleum derivates is desirable. These results demonstrate the versatility of biomolecules with amphipathic nature, a property that makes them increasingly competitive with real possibilities for use in industries. 1. Introduction With the growth of industrial production, many products are improperly accumulated in the environment, contaminating soil and groundwater. Water and soil contaminants include inorganic species such as nitrate and phosphate, heavy metals like cadmium, chromium, mercury, and lead, and organic chemicals, including hydrophobic compounds, inorganic acids and radionuclides [1]. In the natural soil, these contaminants cannot be completely degraded and may be more or less mobile in the soil [2]. The Brazilian Association of Standard Methods (ABNT) defines slurry as a ¡°liquid produced by the decomposition of substances in urban solid residues which features a dark color, a bad smell and a high BOD (Biochemical Oxygen Demand); it constitutes a mixture of organic and inorganic compounds in solution and in colloidal state and of several microorganisms species¡± [3]. The generation of slurry in a landfill is due to the percolation of rainwater infiltrating the landfill and the coverage that exceeds the capacity of the soil to retain the water in its pores (field capacity). Several physicochemical and biological methods, or a combination of both, are used to treat slurry. According to Gomes [4], the biological process allows the biodegradation of organic compounds in slurry by the action of microorganisms that turn them into simpler substances as water, carbon dioxide, and methane. The physical-chemical treatment combined with biological treatment, instead, can eliminate the undesirable leaching of chemical species in the effluent, such as
%U http://www.hindawi.com/journals/aess/2011/939648/