Badania zawartości WWA w osadach ściekowychPAH content variations in some sewage sludges

Investigated were PAH content variations in sewage sludge, as well as in the supernatants. Eight PAH congeners were analyzed, including naphthalene, acenaphthalene, acenaphthene, fluorene, phentanthrene, fluoranthene and pyrene. Total PAH concentration was found to vary from one sludge type to another, but the overall content of PAH congeners in digested sludge was higher than that in the raw sludge. In spite of their non-polar properties and their proneness to adsorb on solid particles, PAHs were detected in all supernatants, but their concentrations were below the solubility limits. Supernatant concentrations of PAH congeners from centrifugation were lower for digested sludge than for raw sludge.