The endocrine disrupting chemical nonylphenol (NP) is a technical product which consists of a complex mixture of nonylphenols with different alkyl side-chain isomers. Since the bio-degradation of each NP isomer may lead to its own range of metabolites, the isolation and identification of transformation products is very difficult. In order to overcome this difficulty, the nonylphenol isomer 4(3',5'-dimethyl-3'-heptyl)-phenol (p353NP) was synthesized, and its degradation by an axenic culture of Sphingomonas TTNP3 was investigated with [ring-U-14C]-labelled and non-labelled p353NP including a time-course study. Radioactive mass balancing resulted in different polar soluble fractions, in insoluble radioactivity associated with biomass, and volatile radioactivity in the form of the mineralization product 14CO2. In the extracellular media, the presence of nonanol corresponding to the nonyl chain of the NP isomer was confirmed and its concentration was determined during the course of fermentation. No other radioactive compounds were detected beside the parent isomer. Radioactive metabolites were only found in the intracellular fraction of S. TTNP3.

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The microbial transformation of typical tar oil compounds such as acridine, benzo(b)thiophene, dibenzofuran, indane, and indene under different redox conditions was investigated in microcosm studies. Under aerobic conditions the inherent contamination in polluted soil as well as the added N-, S-, O-heterocyclic and homocyclic compounds were transformed predominantly apart from thiophene. 1-Indanone was detected by RP-HPLC-DAD and GC-MS as an intermediate metabolite from indane and indene. Under nitrate and sulfate reducing conditions indane, benzo(b)thiophene, and dibenzofuran were transformed in assays with the polluted soil samples from well B 65 and B 66 within 426 days, whereas they were persistent in assays with the highly polluted soil B 67. All heterocyclic and homocyclic compounds added to the non-contaminated soil from well B 85 were not degraded under nitrate and sulfate reducing conditions, too. The results indicate that for the decision, wether natural attenuation can be implemented in the remediation of contaminated site, in addition to BTEX and PAHs especially the fate of further tar oil compounds in anoxic aquifers has to be considered. Mikrobieller Abbau von Teerölbegleitstoffen unter verschiedenen Redox-BedingungenDer mikrobielle Umsatz von typischen Teerölsubstanzen, wie Acridin, Benzo(b)thiophen, Dibenzofuran, Indan und Inden, wurde unter verschiedenen Redoxbedingungen in Mikrokosmen untersucht. Unter aeroben Bedingungen wurde sowohl in belasteten Bodenproben die inhärente Kontamination als auch in unbelasteten Bodenproben die zudotierten heterocyclischen und homocyclischen Verbindungen außer Thiophen überwiegend umgesetzt. 1-Indanon wurde als ein intermediärer Metabolit von Indan und Inden mittels RP-HPLC-DAD und GC-MS nachgewiesen. Unter denitrifizierenden und desulfurizierenden Bedingungen wurden Indan, Benzo(b)thiophen und Dibenzofuran in Ansätzen mit den belasteten Bodenproben von Brunnen B 65 und B 66 innerhalb von 426 Tagen umgesetzt, während sie in denen mit dem hoch belasteten Boden B 67 persistent blieben. Alle heterocyclischen und homocyclischen Stoffe, die den Versuchen mit unbelastetem Boden von Brunnen B 85 zugesetzt wurden, wurden ebenfalls nicht abgebaut. Die Ergebnisse zeigen, dass für die Entscheidung, ob Natural Attenuation an einem Standort implementiert werden kann, neben BTEX und PAK besonders der Verbleib weiterer Teerölverbindungen in anaeroben Aquifern zu prüfen ist.