Study On Pollution Characteristics Of PAHs In Sediments From The Middle And Lower Reaches Of Huaihe River

Based on the analyses of 32 sediment samples from the middle and lower reaches of Huaihe River, the concentration data of 16 PAHs (Polycyclic Aromatic Hydrocarbons) which are priority control pollutants in USA were obtained. Made use of these data, the distribution characteristics of PAHs in sediments along the riverside and across the riversides were studied. At the same time, these property correlations between the PAHs concentrations were analyzed by combining them with 3 items of physicochemical properties of the sediments, which are pH, grain size and organic matter. In addition, the possible pollution sources of PAHs were discussed and their potential ecological risks were assessed. The research results showed as follows: (1) The PAHs concentrations in sediments varied within a wide range and generally took on the trend from high in the middle reach to low in the lower reach along the riverside. On the other hand, from the angle of single component, three components which are phenanthrene, fluoranthene and pyrene respectively, were predominant while the others were relatively low. (2) The PAHs distribution obviously was affected by man-made pollution sources and water driving force conditions. PAHs concentrations were high near intensive resources and were low in the areas where water driving force conditions are strenuous. (3) The PAHs concentrations had a negative correlation with pH, and a positive correlation with the particle of ≤60μm, a good positive correlation with organic matter. (4) Both the varieties and aromatic rings distribution of PAHs and the ratios of phenanthrene to anthracene and fluoranthene to pyrene suggested PAHs in sediments from Hetaidukou to Xinji was mainly derived from combustion and pyrolysis of fossil fuels in high temperature while that from Anhuai to Xiaohetou was mostly identified from incomplete combustion of fossil fuels in low and moderate temperature or diagenetic stage. (5) Compared with the corresponding ecological risk assessmet guidelines, Huainan areas would have potential ecological risks while others would have relatively low ones.