engleski

Determination of nonylphenolic compounds in sewage treatment by high-performance liquid chromatography and tandem mass spectrometry

Aromatic surfactants of nonylphenol polyethoxylate (NPnEO) type with estimated annual worldwide production rates of about 6 x 105 tons belong to the most popular surfactant classes. NPnEO exhibit a complex metabolic behaviour in wastewater treatment plants (WWTPs) and natural waters, yielding a variety of relatively stable metabolic products. Due to the widespread use of NPnEO and considerable toxicities of their alkylphenol moietycontaining metabolites to the aquatic life, surfactant-derived nonylphenolic compounds should be considered potentially important environmental contaminants. In addition, most of alkylphenolic metabolites were reported to be weakly estrogenic to fish. The aim of this study was to determine the compositional changes of nonylphenolic compounds in Croatian municipal wastewaters and treated effluents using high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) with a special emphasis on the assessment of potential toxic and endocrine-disrupting effects. The analysis comprised the determination of parent compounds (NPnEO) as well as their stable degradation products, including nonylphenol (NP), nonylphenol mono- and diethoxylates (NP1EO and NP2EO) and nonylphenoxy carboxylic acids (NPnEC). It was shown that the composition of nonylphenolic compounds in raw wastewaters might often be ecotoxicologically rather unfavourable due to the enhanced relative contributions of the toxic and endocrine-disrupting alkylphenolic compounds such as nonylphenols (NP) and lipophylic NPnEO that are formed under hypoxic conditions in the sewer system. The aerobic sewage sludge treatment reduces the toxic effects associated with nonylphenolic compounds, while a more careful assessment is needed to evaluate possible endocrine-disrupting effects.

nonylphenolic compounds; sewage

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