Journal of Microbial & Biochemical Technology

Soil washing with biologically compatible surfactants: A strategy to stimulate hydrocarbon biodegradation in soils contaminated with excess oil and saline produced water

Joint Event on 4^th World Congress and Expo on Applied Microbiology & 2^nd International Conference on Food Microbiology

November 29-December 01, 2017 Madrid, Spain

Marcos Rogerio Totola, Silvia Cristina de Souza, Nathalia Rezende de Assis Alves, Celia Marcela Camacho Montealegre, Mateus Tomaz Neves, Adriana Ururahy Soriano and Luiz Fernando Martins

Universidade Federal de Vi�?§osa, Brazil
CENPES, Brazil

Posters & Accepted Abstracts: J Microb Biochem Technol

Abstract:

Contamination of soils and aquifers is one of the environmental issues linked to oil and gas exploitation activities. In mature onshore oilfields, usually more than 90% of the volume exiting the reservoir corresponds to hypersaline produced water. In these cases, occasional spills from oil pipelines imply soil contamination with oil and high amount of salts. Bioremediation is generally the most cost effective approach for the remediation of oil polluted soils. However, high inputs of oil and salts into the soil can significantly decrease microbial activity (this work), making bioremediation unfeasible. In such scenario, the only possibility of obtaining satisfactory results with bioremediation is the reduction of total hydrocarbon and salt contents in the contaminated soil. Soil washing with chemical surfactants or microbial biosurfactants has been satisfactorily employed for removal of hydrophobic contaminants, including hydrocarbons. However, there are no reports of the adoption of this technique aiming at salinity decreasing as well. In this work, aqueous solutions of alkyl polyglycosides and a biosurfactant (rhamnolipid) were used to treat soils contaminated with crude oil (300,000 mg/kg) and NaCl (80,000 mg/kg). The variables included (bio) surfactant concentration, washing solution/soil ratio, time and speed of stirring and decantation, and presence of different salts (Na2CO3, Na2SiO3 or KCl) in the washing solution. Oil removal (TPH) at optimized conditions was around 70% for clayey soils and 99% for a sandy loam soil. Reduction of soil salinity was equally effective, resulting in soil electrical conductivity values compatible with the establishment and activity of hydrocarbonoclastic microbial populations. We conclude that soil washing with environmentally friendly (bio)surfactants is recommended to stimulate hydrocarbon biodegradation in soils impacted by oil and hypersaline produced water-spills.

Biography :

Marcos Rogério Tótola has completed his PhD from Universidade Federal de Viçosa and Post-doctoral studies from University of Arizona. He is the Head of the Laboratório de Biotecnologia e Biodiversidade para o Meio Ambiente, UFV. He is a founder member of the Brazilian Advisory Council of the Brazilian Microbiology Project (http://www.brmicrobiome.org/). He has published more than 60 articles in renowned journals and serves as a member of the editorial board of several leading scientific journals.