Microbiological degradation of polycyclic aromatic hydrocarbons: Anthracene,benzo(K)fluoranthene,dibenzothiophene, benzo(H) quinoline and 2‐nitronaphthalene

Biodegradation experiments of various polycyclic aromatic hydrocarbons were studied with mixed bacteria culture under aerobic conditions. An easy‐to‐handle clean‐up procedure was developed for PAH and their metabolites simultaneously as well as a gc‐ms‐method to identify and quantify these compounds.

Anthracene and dibenzothiophene are completely degradable in an aqeous system, whereas biodegradation of benzo(k)fluoranthene and benzo(h)quinoline is possible only in an oil‐in‐water‐system with dodecane as cosubstrate. No degradation of nitronaphthalene was observed in aqueous systems. New metabolites are 2,3‐dihydroxybenzothiophene, hydroxybenzothiophenecarbonic acid and benzothiophenequinone for dibenzothiophene and hydroxyfluoranthenic acid for benzo(k)flouranthene. Whereas the former metabolites are degradable under the experimental conditions, the latter accumulates during the degradation experiment.

The results are important for microbiological wastewater treatment, since knowledge of biodegradation processes is indespensable for the successful treatment of PAH‐containing wastewater.