Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAH) in water and sediments of the Luan River, China

Abstract

The distribution of polycyclic aromatic hydrocarbons (PAH) was studied by determining the levels of 16 PAH in the water and sediment samples of the Luan River; a very important drinking water source for Tianjin and Tangshan in Hebei province, China. A total of 11 water samples and 11 sediment samples were collected in April 2008. The total PAH concentrations in water varied from 9.8 to 310 ng L−1, and those in surficial sediments ranged from not detected (ND) to 478 ng g−1 dry weight. The results showed that the upstream and downstream areas were low-polluted and high-polluted sites concentrated in the middle reaches of the river, respectively. The concentrations of PAH in rural areas (5 sites), which could be considered as the “background” levels, were lower than those near city zones (6 sites), which could be regarded as the “maximum” values. The PAH were dominated by 3- (38.4%) and 4-ring (60.7%) components in water samples and by 3- (27.4%), 4- (38.5%), and 5-ring (15.8%) compounds in sediments. High molecular weight PAH were inclined to be absorbed into sediments. The 3- and 4-ring PAH were the most common components in the Luan River. The molecular indices and the distribution of different rings were used to infer the sources of PAH, and the results suggested that anthropogenic heavy fuel combustion was likely to be the main source. The petroleum PAH had a high contribution to the PAH pollution at Baohekou and Daheiting.