title: Trimethylbenzoic acids as metabolite signatures in the biogeochemical evolution of an aquifer contaminated with jet fuel hydrocarbons.
abstract: Evolution of trimethylbenzoic acids in the KC-135 aquifer at the former Wurtsmith Air Force Base (WAFB), Oscoda, MI was examined to determine the functionality of trimethylbenzoic acids as key metabolite signatures in the biogeochemical evolution of an aquifer contaminated with JP-4 fuel hydrocarbons. Changes in the composition of trimethylbenzoic acids and the distribution and concentration profiles exhibited by 2,4,6- and 2,3,5-trimethylbenzoic acids temporally and between multilevel wells reflect processes indicative of an actively evolving contaminant plume. The concentration levels of trimethylbenzoic acids were 3-10 orders higher than their tetramethylbenzene precursors, a condition attributed to slow metabolite turnover under sulfidogenic conditions. The observed degradation of tetramethylbenzenes into trimethylbenzoic acids obviates the use of these alkylbenzenes as non-labile tracers for other degradable aromatic hydrocarbons, but provides rare field evidence on the range of high molecular weight alkylbenzenes and isomeric assemblages amenable to anaerobic degradation in situ. The coupling of actual tetramethylbenzene loss with trimethylbenzoic acid production and the general decline in the concentrations of these compounds demonstrate the role of microbially mediated processes in the natural attenuation of hydrocarbons and may be a key indicator in the overall rate of hydrocarbon degradation and the biogeochemical evolution of the KC-135 aquifer.
authors: National Center for Integrated Bioremediation Research and Development, Department of Civil and Environmental Engineering, The University of Michigan, Ann Arbor, MI 48109, USA.
authors: J A
authors: JA
authors: Namocatcat
authors: J
authors: J
authors: Fang
authors: M J
authors: MJ
authors: Barcelona
authors: A T O
authors: AT
authors: Quibuyen
authors: T A
authors: TA
authors: Abrajano
mesh_terms: D001565:Benzoates / Q000737:chemistry / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring; D006838:Hydrocarbons / Q000737:chemistry / Q000378:metabolism*; D007648:Kerosene; D012016:Reference Values; D012989:Soil Pollutants / Q000378:metabolism*; D014881:Water Supply
chemical_list: D001565:Benzoates; D006838:Hydrocarbons; D007648:Kerosene; D012989:Soil Pollutants; C029662:JP5 jet fuel