title: The primary aerobic biodegradation of biodiesel B20.
abstract: We describe the primary aerobic biodegradation of a B20 fuel (20% soybean fatty acid methyl esters, 80% petroleum diesel) by unacclimated inocula from a rainwater detention pond. Biodegradation was rapid and essentially complete, with an overall median 'half-life', at approximately 100 ppm B20, of 6.8 days (n=34). Using purge-and-trap and extraction methodologies, both coupled to GC/MS, and hexachloroethane and hexachlorobenzene as conserved internal markers in the B20, we followed the biodegradation of total detectable material, 76 individual analytes and eight undifferentiated groups of isomers, and calculated their half-lives under these conditions. The fatty acid methyl esters, n-alkanes and iso-alkanes, and simple and alkylated aromatic compounds were the most readily degraded compounds, followed by the naphthenes. The last (identified) compounds to be degraded were ethylalkanes, trisubstituted cyclohexanes and decalins, but even these disappeared with an apparent 'half-life' of <30 days.
authors.affiliation: ExxonMobil Biomedical Sciences, Inc., 1545 Route 22E, Annandale, NJ 08801, United States. roger.c.prince@exxonmobil.com
authors.forename: Roger C
authors.initials: RC
authors.lastname: Prince
authors.forename: Christine
authors.initials: C
authors.lastname: Haitmanek
authors.forename: Catherine Coyle
authors.initials: CC
authors.lastname: Lee
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D005742:Gasoline; D013025:Glycine max / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D005742:Gasoline