title: Anaerobic biodegradation of soybean biodiesel and diesel blends under methanogenic conditions.
abstract: Biotransformation of soybean biodiesel and the inhibitory effect of petrodiesel were studied under methanogenic conditions. Biodiesel removal efficiency of more than 95% was achieved in a chemostat with influent biodiesel concentrations up to 2.45 g/L. The kinetics of anaerobic biodegradation of soybean biodiesel B100 (biodiesel only) with different petrodiesel loads was studied using biomass pre-acclimated to B100 and B80 (80% biodiesel and 20% petrodiesel). The results indicated that the biodiesel fraction of the blend could be effectively biodegraded, whereas petrodiesel was not biodegraded at all under methanogenic conditions. The presence of petrodiesel in blends with biodiesel had a greater inhibitory effect on the rate of biodegradation than the biodegradation efficiency (defined as the efficiency of methane production). Both the biodegradation rate coefficient and the methane production efficiency increased almost linearly with the increasing fraction of biodiesel. With the increasing fraction of petrodiesel, the biodegradation rate and efficiency were correlated with the concentration of soluble FAMEs in the water.
authors.affiliation: Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45220, United States.
authors.forename: Shuyun
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Mathematics and Natural Sciences, College of Arts and Sciences, Gulf University for Science and Technology, Hawally 32093, Kuwait.
authors.forename: Mohamad H
authors.initials: MH
authors.lastname: Yassine
authors.affiliation: Faculty of Engineering and Architecture, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon. Electronic address: msuidan@aub.edu.lb.
authors.forename: Makram T
authors.initials: MT
authors.lastname: Suidan
authors.affiliation: U.S. Environmental Protection Agency (retired), National Risk Management Research Laboratory, 26 W. Martin Luther King Drive, Cincinnati, OH 45268, United States.
authors.forename: Albert D
authors.initials: AD
authors.lastname: Venosa
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis*; D005742:Gasoline / Q000032:analysis*; D007700:Kinetics; D008697:Methane / Q000096:biosynthesis*; D013025:Glycine max / Q000737:chemistry*
chemical_list: D056804:Biofuels; D005742:Gasoline; D008697:Methane
keywords: Anaerobic biodegradation kinetics; Biodiesel; Inhibition; Petrodiesel