Evidence for in situ Degradation of Mono-and Polyaromatic Hydrocarbons in Alluvial Sediments Based on Microcosm Experiments with super(13)C-Labeled Contaminants

Evidence for in situ degradation of mono- and polyaromatic hydrocarbons in alluvial sediments based on microcosm experiments with super(13)C-labeled contaminants was investigated. The distribution of the intrinsic biodegradation potential was investigated in sediments sampled from the vadose and from the saturated zone of 7 different drilling locations. The results showed that this newly developed screening approach had the potential to be used for the evaluation of intrinsic biodegradation of further contaminants even when they were slowly degraded or partly sorbed on surfaces. Results on in situ degradation of contaminants by the intrinsic bacterial community and under in situ conditions could be elegantly used to round up field studies. To systematically investigate parameters that might limit biodegradation in situ, incubation conditions could be varied easily in microcosm experiments.