The distribution and toxicity evaluation of polycyclic aromatic hydrocarbons in the textile dyeing sludge

Within this study, the focus of the investigation was on the concentration, toxicity and skin sensitization of 16 PAHs (polycyclic aromatic hydrocarbons) in six textile dyeing sludges, which were analyzed by the gas chromatogram-mass spectrometer, Ecological Structure Activity Relationships (ECOSAR) and Pred-Skin, respectively. The concentration of Sigma 16PAHs of the sludges fell in the range of 983.52-2,026.88 ng g(-1). And the majority of PAHs were low molecular weight PAHs, which was due to different raw materials and wastewater treatment processes. The acute toxicity values of 16 PAHs to fish, daphnia and algae were 0.014-9.390, 0.012-5.940, and 0.054-6.910 mg L-1, respectively. The chronic toxicity values of PAHs to fish, daphnia and algae were 0.002-1.040, 0.004-0.782, and 0.037-2.300 mg L-1, respectively. Toxicity evaluation found that PAHs were toxic to organisms, even deadly toxic. Sensitization probability of PAHs by Pred-Skin showed different prediction results from five prediction models, but all indicated that most of the PAHs had a sensitization effect on the human body, with a probability of over 80.0%. This article is trying to draw people's attention to the toxicity and sensitization of PAHs in the textile dyeing sludge, in order to provide theoretical guidance for the reduction and detoxification of textile dyeing sludge.