Occurrence of polycyclic aromatic hydrocarbons in sewage sludge and their contribution to its toxicity in the ToxAlert® 100 bioassay Original Research Article

The contribution of polycyclic aromatic hydrocarbons (PAH) present in sewage sludge samples to toxicity was investigated. Chemical analysis using gas chromatography–mass spectrometry (GC–MS) and the ToxAlert® 100 bioassay, based on the inhibition to Vibrio fischeri, were applied to sludge extracts after purification by column chromatography. The levels of the 16 US EPA PAH analyzed in the sewage sludge samples varied from 17 to 2030 μgkg−1. In all samples examined phenanthrene was the most prominent compound. The toxicity data obtained by ToxAlert® 100 can be explained by the levels and composition of the different PAH in sewage sludge samples. The present approach can contribute to evaluate the toxicity of sewage sludge.