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
References
[1]
D. L. Sparks, Environmental Soil Chemistry, Academic Press, San Diego, Calif, USA, 1995.
[2]
D. S. Burden and J. L. Sims, Fundamentals of Soil Science as Applicable to Management of Hazardous Wastes, United States Environmental Protection Agency, Washington, DC, USA, 1998.
[3]
ABNT, Associa？？o Brasileira de Normas Técnicas. NBR 10.005: Procedimento para obten？？o de extrato lixiviado de resíduos sólidos. Rio de Janeiro, Brazil, 2004.
[4]
L. P. Gomes, Gera？？o, características e processos relacionados ao chorume gerado pela degrada？？o de resíduos sólidos urbanos. Revista do Centro de Ciências Exatas e Tecnológicas da UNISNOS. S？o Leopoldo, Brazil, 2000.
[5]
S. S. Suthersan, Remediation Engineering: Design Concepts, Lewis publishers, Boca Raton, Fla, USA, 1996.
[6]
R. C. Starr and J. A. Cherry, “In situ remediation of contaminated ground water: the funnel-and-gate system,” Ground Water, vol. 32, no. 3, pp. 465–476, 1994.
[7]
M. M. M. Nobre, “Estudos para execu？？o de uma barreira reativa objetivando o controle da migra？？o de uma pluma de mercúrio,” 5o Congresso Brasileiro de Geotecnia Ambiental (REGEO '03), Porto Alegre, Brazil, 2003.
[8]
C. Calvo, M. Manzanera, G. A. Silva-Castro, I. Uad, and J. González-López, “Application of bioemulsifiers in soil oil bioremediation processes. Future prospects,” Science of the Total Environment, vol. 407, no. 12, pp. 3634–3640, 2009.
[9]
K. Muthusamy, S. Gopalakrishnan, T. K. Ravi, and P. Sivachidambaram, “Biosurfactants: properties, commercial production and application,” Current Science, vol. 94, no. 6, pp. 736–747, 2008.
[10]
C. N. Mulligan, R. N. Yong, and B. F. Gibbs, “Surfactant-enhanced remediation of contaminated soil: a review,” Engineering Geology, vol. 60, no. 1–4, pp. 371–380, 2001.
[11]
R. D. Rufino, L. A. Sarubbo, and G. M. Campos-Takaki, “Enhancement of stability of biosurfactant produced by Candida lipolytica using industrial residue as substrate,” World Journal of Microbiology and Biotechnology, vol. 23, no. 5, pp. 729–734, 2007.
[12]
ABNT, “Associa？？o Brasileira de Normas Técnicas,” NBR 7181: Solos: Análise granulométrica conjunta. Rio de Janeiro, Brazil, 1984.
[13]
ABNT, “Associa？？o Brasileira de Normas Técnicas,” NBR 6459: Solos: determina？？o do limite de liquidez. Rio de Janeiro, Brazil, 1984.
[14]
ABNT, “Associa？？o Brasileira de Normas Técnicas,” NBR 7180: Solos: determina？？o do limite de plasticidade. Rio de Janeiro, Brazil, 1984.
[15]
ABNT, “Associa？？o Brasileira de Normas Técnicas,” NBR 6508: Massa Específica dos gr？os dos solos. Rio de Janeiro, Brazil, 1984.
[16]
ABNT, “Associa？？o Brasileira de Normas Técnicas,” NBR 7182: Solos: ensaio de compacta？？o. Rio de Janeiro, Brazil, 1986.
[17]
Empresa Brasileira de Pesquisa Agropecuária-EMBRAPA, Manual de Métodos de Analise de Solo, Centro Nacional de Pesquisas de Solos, Rio de Janeiro, Brazil, 2nd edition, 1997.
[18]
M. O. A. Mariano, Avalia？？o da reten？？o de gases em camadas de cobertura de aterros de resíduos sólidos, Tese de Doutorado, Universidade Federal de Pernambuco, Pernambuco, Brazil, 2008.
[19]
APHA, Standard Methods for Examination of Water and Wastewater, American Public Health Association, Washington, DC, USA, 19th edition, 1995.
[20]
H. P. Caputo, Mecanica dos Solos e Suas Aplica？？es, Livros Técnicos e Científico, Rio de Janeiro, Brazil, 1988.
[21]
J. C. Carvalho, “Propriedades de comportamento de solos tropicais n？o saturados,” in Proceedings of the Simpósio Brasileiro de Solos n？o Saturados, vol. 2, S？o Paulo, Brazil, 2004.
[22]
J. F. Peng, Y. H. Song, P. Yuan, X. Y. Cui, and G. L. Qiu, “The remediation of heavy metals contaminated sediment,” Journal of Hazardous Materials, vol. 161, no. 2-3, pp. 633–640, 2009.
[23]
Y. A？？i, M. Nurba？, and Y. S. A？ikel, “Sorption of Cd(II) onto kaolin as a soil component and desorption of Cd(II) from kaolin using rhamnolipid biosurfactant,” Journal of Hazardous Materials, vol. 139, no. 1, pp. 50–56, 2007.
[24]
Y. A？？i, M. Nurba？, and Y. S. A？ikel, “A comparative study for the sorption of Cd(II) by soils with different clay contents and mineralogy and the recovery of Cd(II) using rhamnolipid biosurfactant,” Journal of Hazardous Materials, vol. 154, no. 1–3, pp. 663–673, 2008.
[25]
CETESB, Companhia Ambiental do Estado de S？o Paulo. Relatório de estabelecimento de valores orientadores para solos e águas subterraneas no estado de S？o Paulo. S？o Paulo, Brazil, 2001.
[26]
K. J. Hong, S. Tokunaga, and T. Kajiuchi, “Evaluation of remediation process with plant-derived biosurfactant for recovery of heavy metals from contaminated soils,” Chemosphere, vol. 49, no. 4, pp. 379–387, 2002.
[27]
C. N. Mulligan, R. N. Yong, B. F. Gibbs, S. James, and H. P. J. Bennett, “Metal removal from contaminated soil and sediments by the biosurfactant surfactin,” Environmental Science and Technology, vol. 33, no. 21, pp. 3812–3820, 1999.
[28]
B. Dahrazma and C. N. Mulligan, “Investigation of the removal of heavy metals from sediments using rhamnolipid in a continuous flow configuration,” Chemosphere, vol. 69, no. 5, pp. 705–711, 2007.
[29]
J. W. Neilson, J. F. Artiola, and R. M. Maier, “Characterization of lead removal from contaminated soils by nontoxic soil-washing agents,” Journal of Environmental Quality, vol. 32, no. 3, pp. 899–908, 2003.
