Concentration of PAHs in Municipal Wastewater in Selected Sewer Collectors of the Upper Silesian Urban Area, Poland

Polycyclic aromatic hydrocarbons (PAHs) constitute a large group of organic compounds that make constant threat to the environment. Their contents from natural sources are low. The processes of incomplete organic fuel combustion are the main sources of PAHs. In Upper Silesia (Poland), large amounts of PAHs are emitted into the air as a result of coal combustion in home furnaces and liquid fuel burning in combustion engines (low emission). PAHs get into surface water because of the surface runoff and point source wastewater discharges from certain industries. The following study presents PAHs concentrations in raw municipal wastewater. The tests were performed out of the heating season. The samples were collected from the combined sewer system. The analyses of PAHs were carried out with gas chromatography coupled with a mass detector (GC-MS). The concentrations of 16 PAHs sum (EPA list) ranged between 1.025 and 3.056 μg/L. Phenanthrene dominated in nearly all the analysed samples. The contents of PAHs, which are priority hazardous substances according to the directive, were high in the analysed samples. The obtained results and the analysis of diagnostic ratios for the emissions of PAHs into the air helped to reach the conclusion that traffic emissions were the main source of PAHs in the examined wastewater