Composition, source identification and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments of the Subei Grand Canal, China

Abstract

Polycyclic aromatic hydrocarbons (PAHs) in sediments of the Subei Grand Canal (SGC) are thought to have a significant effect on the water quality of the South to North Water Transfer Project in China. The SGC is in Jiangsu Province and is the northern section of the Beijing-Hangzhou Grand Canal; it is also part of the eastern route of the South to North Water Transfer Project. In the present study, 37 surface sediment samples were collected from the SGC and were analyzed by high performance liquid chromatography (HPLC) for their PAH concentration. The total PAH concentration in surface sediments was moderate, and ranged from 634 to 14,703 ng/g (dry weight), with a mean of 5239 ng/g. There was significant spatial variation in the total PAH concentrations; for example, the mean concentrations in the Xuzhou area, Huaian-Suqian area, and Yangzhou area were 9708, 3872 and 2376 ng/g, respectively. The organic carbon content (9.4–99.6 mg/g) had an important influence on the PAH concentrations in sediment. Analysis using PAH ratios and PCA indicated that the main sources were coal and wood combustion, vehicular and shipping emissions, and coke ovens. An ecological risk assessment based on biological threshold showed that the PAH in surface sediments of the SGC had the potential to cause adverse biological effects to aquatic organisms, and that these effects were more serious around Xuzhou than in the other areas.