es034417r_si_001.pdf (108.69 kB)
Hydrogen and Carbon Isotope Fractionation during Anaerobic Biodegradation of Aromatic HydrocarbonsA Field Study
journal contribution
posted on 2004-01-15, 00:00 authored by Alfred Steinbach, Richard Seifert, Eva Annweiler, Walter MichaelisThe aquifer of a former manufactured gas plant site,
highly contaminated by dissolved monocyclic, heterocyclic,
and polycyclic aromatic hydrocarbons, was studied to
evaluate the applicability of carbon and hydrogen isotope
fractionation to prove ongoing biodegradation of these
compounds even in complex aquifer settings. The loss of
toluene, o-xylene, p,m-xylene, and 2-methylnaphthalene was
accompanied by a considerable carbon isotope fractionation.
Additionally, a strong 2H enrichment in residual o-xylene
was detected. All isotope fractionations observed could be
related to established biochemical degradation mechanisms,
each involving a C−H bond cleavage in the rate-determining step. In contrast, other compounds such as
1-methylnaphthalene, methylbenzofuran, and acenaphthene
exhibited a uniform stable carbon isotope composition.
However, a decrease in concentration for these compounds
was observed in the flowpath of the aquifer. High threshold
concentrations of acenaphthene downgradient indicate
that this contaminant is, if at all, only marginally biodegraded.
Detailed analyses of xylenes provided support that
compound specific isotope analyses and subsequent
application of the Rayleigh model may provide a valuable
basis to distinguish between different biodegradation
mechanisms as well as dissolution processes in heterogeneous aquifers.
History
Usage metrics
Categories
Keywords
Carbon Isotope Fractionationaquifer settingscompoundbiodegradation mechanismsHigh threshold concentrationsdissolution processesAnaerobic Biodegradation2 H enrichmentRayleigh modelacenaphthene downgradientgas plant siteisotope fractionationscarbon isotope fractionationisotope analysesdegradation mechanismshydrogen isotope fractionationcarbon isotope compositionmethylnaphthalenexylene
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC