Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Detection, and Remediation® Conference

Tuesday, November 4, 2008 : 3:35 p.m.

Anaerobic Biodegradation of a LNAPL In a Continuous-Flow Fixed-Biofilm Reactor

Karim Acuna-Askar, Sc.D., Karen H. Lozano-Rodriguez, Rolando Tijerina-Menchaca, M.D., Maria T. Garza-Gonzalez, Sc.D., Juan A. Vidales-Contreras, Ph.D., Universidad Autonoma de Nuevo Leon, German Buitron-Mendez, Universidad Nacional Autonoma de Mexico Instituto and Benjamin Chavez-Gomez, Sc.D., Instituto Mexicano

The goal of this study was to evaluate the biodegradability of a light nonaqueous phase liquid (LNAPL) by a continuous-upflow fixed-biofilm reactor under anaerobic conditions.  A LNAPL sample was separated from a shallow contaminated groundwater body at a petroleum refinery site and treated in a laboratory scale bioreactor by a microbial biofilm. A microbial consortium originally taken from a petrochemical wastewater treatment plant was grown on a microbial support made of alluvial and volcanic stones in the bioreactor for the biofilm to develop.  LNAPL biodegradation was evaluated at an oxidation-reduction potential (ORP) range between   -362 and -480 mv and at a hydraulic retention time (HRT) of 12 hours.  Strong reducing conditions and depleted dissolved oxygen were maintained in the culture medium with Titanium (III) citrate as a buffering system.  The biodegradation profile was modeled throughout the column height at steady-state conditions.  Relevant bioreactor conditions ranged for pH 6.8-7.1; for D.O. 0.0-0.04% at the controlled temperature range of 26-27oC. A first-order two-phase kinetic model was used to describe LNAPL biodegradation patterns.  Quantitative evaluation based on calibration curves and statistical tests revealed that 94.7% of the LNAPL was biodegraded under the aforementioned conditions. 

Karim Acuna-Askar, Sc.D. Professor and Head, Environmental Bioremediation Research Laboratory, Department of Microbiology, School of Medicine, Autonomous University of Nuevo Leon. Received Doctor of Science degree in Environmental Health Sciences, Water Quality Program from Tulane University, New Orleans, LA, in 1998. Master of Science degree in Analytic Chemistry, Autonomous University of Nuevo Leon, in 1991. Bachelor of Science in Chemistry, Monterrey Institute of Technology in 1986.

Karen H. Lozano-Rodriguez Student, Bachelor of Science degree in Chemistry, Autonomous University of Nuevo Leon School of Chemical Sciences. Research Assistant in the Environmental Bioremediation Research Laboratory, Department of Microbiology, School of Medicine, Autonomous University of Nuevo Leon.

Rolando Tijerina-Menchaca, M.D. Professor and Chairman, Department of Microbiology. Received Doctor of Medicine degree from University of Hamburg, Germany in 1983. Bachelor degree in Medicine, Autonomous University of Nuevo Leon, in 1975.

Maria T. Garza-Gonzalez, Sc.D. Professor and Associate Dean for Graduate Studies, School of Chemical Sciences, Autonomous University of Nuevo Leon. Received Doctor of Science degree in Microbiology from University of La Habana, Cuba in 2005. Master of Science degree in Industrial Microbiology, Autonomous University of Nuevo Leon, 1993. Bachelor of Science degree in Chemistry, Autonomous University of Nuevo Leon in 1974.

Juan A. Vidales-Contreras, Ph.D., Universidad Autonoma de Nuevo Leon Professor and Chairman, Department of Agricultural Engineering, School of Agronomy, Autonomous University of Nuevo Leon. Ph.D., Soil, Water and Environmental Science, from University of Arizona, 2001. Master of Science in Groundwater Hydrology, Autonomous University of Nuevo Leon, in 1983. Bachelor of Science degree in Agronomy, Autonomous University of Nuevo Leon, 1981.

German Buitron-Mendez, Universidad Nacional Autonoma de Mexico Instituto Professor and Head, Laboratory of Advanced Research on Water Processes, Institute of Engineering, National Autonomous University of Mexico. Received Doctor of Science degree in Chemical Engineering, Water Treatment program, from the National Institute of Applied Science, Toulouse, France in 1993. Master of Science degree in Chemical Engineering, Water Treatment program, National Institute of Applied Science, Toulouse, France, 1990. Bachelor of Science degree in Chemical Engineering from the National Autonomous University of Mexico in1987.

Benjamin Chavez-Gomez, Sc.D., Instituto Mexicano Researcher, Mexican Petroleum Institute. Doctor of Science and Master of Science degrees in Biotechnology from the Advanced Research Center of the National Polytechnic Institute of Mexico. Bachelor of Science degree in Biochemical Engineering from the National School of Biological Sciences of the National Polytechnic Institute of Mexico. Current projects include bioremediation of soil and groundwater contaminated with hydrocarbons.


Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Detection, and Remediation® Conference