Charakterisierung des mikrobiellen Schadstoffabbaus in kontaminierten Grundwasserleitern mit Hilfe stabiler Isotope
The qualitative and quantitative investigation of in situ- biodegradation of pollutants is important for characterizing the natural attenuation potential of aquifers. As was shown recently, the analysis of changes in carbon and hydrogen isotope signature of pollutants provides an appropriate method for quantification of biodegradation within a contaminant plume. In most cases, microorganisms convert molecules consisting of light isotopes faster than molecules consisting of heavy isotopes. Thus, biodegradation leads to an enrichment of heavy isotopes in the residual fraction of pollutants. It could be shown that the analysis of isotope fractionation of pollutants, the detection of isotope signatures of mineralisation products as well as electron acceptors, and the use of isotopic labelled compounds for tracer and BACTRAP experiments can considerably contribute to the investigation of biodegradation within contaminated aquifers. Therefore, methods based on stable isotopes are suitable for the evaluation of both natural attenuation of a contaminated aquifer and remediation approaches based upon the stimulation of pollutant biodegradation.