engleski

Assessment of emerging contaminants in municipal wastewaters - a transition country perspective

Abstract: A comprehensive survey of municipal wastewaters for organic contaminants was performed using mass spectrometric techniques, including gas chromatography mass spectrometry (GC/MS) and liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS). The study comprised analyses of wastewater samples from all major cities in Croatia. A preliminary qualitative screening, involving full scan analyses in both positive and negative ionization modes, revealed a complex composition of the present contaminants, characterised by a strong predominance of medium-polar and polar contaminants over the nonpolar ones. The major constituents of all extracts were various detergent-derived organic compounds, reaching typically mg/L concentration range. In addition, significant levels of pharmaceuticals were found in all investigated samples. Subsequent quantitative analyses of major representatives of these two contaminant classes, including aromatic surfactants and antimicrobials, respectively, showed their widespread occurrence in untreated municipal wastewaters. In addition, the investigation was extended to study behavior of the selected contaminants during wastewater treatment. It was shown that surfactant-derived compounds were subject to marked changes during the sewage treatment due to the biological transformations and physico-chemical partitioning, while most of pharmaceuticals showed rather modest elimination efficiencies. The study indicated that the elimination efficiencies of the existing conventional wastewater treatment technologies were often inadequate, especially with respect to polar recalcitrant compounds such as pharmaceuticals and some metabolic products of nonionic surfactants.

emerging contaminants; municipal wastewaters; identification

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