Concentrations and Seasonal Variations of Perfluorinated Compounds in Sludge from Three Wastewater Treatment Plants in China

An analytical method based on liquid chromatography with triple quadrupole mass spectrometry has been developed to monitor 16 perfluorinated compounds in sludge samples. The sludge samples were collected from three wastewater treatment plants that were located in a perfluorinated compound production region (Yingcheng City), electroplating industrial region (Cixi City), and a background area (Haikou City). The average annual concentrations of total perfluorinated compounds in sludge samples were from 4.95 to 980 ngGreek ano teleiag(-1 )dry weight. Perfluoro-octane sulfonic acid and perfluoro-octanoic acid were the predominant chemicals in these three wastewater treatment plants. The levels of total perfluorinated compounds were higher in summer than in winter. This phenomenon may be due to input from rainfall in the summer, which may contain more perfluorinated compounds from the surface soil or atmosphere in those regions. Similar sources were found in Yingcheng City and Cixi City based on principal component analysis.