Occurrence and distribution of phthalic acid esters and phenols in Hun River Watersheds

The Xi River (XR) and Pu River (PR) are the tributaries of Hun River Watersheds (HRW), located in Liao River Basin (LRB), northeast China. These riverine waters are historically polluted by effluents from printing and dyeing enterprises, and pharmaceutical and chemical industries. The concentrations of phthalic acid esters (PAEs), e.g., dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), di-n-octyl phthalate (DNOP) and bis(2-ethylhexyl) phthalate (DEHP), as well as phenols including phenol, 4-methylphenol, 2,3-dimethylphenol, 2,4-dimethylphenol, 3,5-dimethylphenol, 2,4,6-trimethylphenol, 2,4-di-tert-butylphenol and 2,6-di-tert-butyl-4-ethylphenol in surface water of the XR and PR were determined by gas chromatograph (GC) coupled with a mass spectrometer (MS), respectively, during spring (dry), summer (wet) and autumn (normal) seasons. DMP, DIBP, DBP, phenol, 4-methylphenol and 3,5-dimethylphenol were identified as the dominant pollutants in the XR, and DBP, DIBP, DEHP and phenol were the main pollutants in the PR. Seasonal variations of the geometric mean concentrations in the XR ranged from 6.88 to 19.5 mu g/L for Sigma(6)PAEs and 24.5-1195 mu g/L for Sigma(8)phenols with the highest level in summer. The temporal distribution of Sigma(6)PAEs or Sigma(8)-phenols in the PR was similar to that in the XR, i.e. the highest levels were observed in summer (24.1 mu g/L for Sigma(6)PAEs and 26.8 mu g/L for Sigma(8)phenols). The concentrations of pollutants were highly variable across sampling sites. The geographic concentrations of Sigma(6)PAEs were in the range of 9.92-17.9 mu g/L in the XR and 7.42-37.6 mu g/L in the PR. As for Sigma(8)phenols, the greater spatial variations were observed, ranging from 14.0-2008 mu g/L in the XR and from 4.00 to 80.5 mu g/L in the PR. Cluster analysis (CA) showed that the 19 sampling stations were divided into three clusters: cluster A was made up of the majority of sampling sites in the PR, slightly polluted by PAEs and phenols; cluster B consisted of the sites from both the XR and PR; cluster C included the sampling sites in the XR, where was heavily polluted by PAEs and phenols.