[Distribution, source and risk assessment of polycyclic aromatic hydrocarbons in river sediment of Cheng-Yu economic zone].

The USEPA 16 priority pollutant dominated polycyclic aromatic hydrocarbons (PAHs) in the surface river sediments of Sichuan Province and Chongqing City in southwest China were determined using GC-MS. The result showed the content of PAHs in the sediment ranged from 48.2 ng/g to 723.1 ng/g, with an average value of 276.1 ng/g. Among which, the maximum content was found in Shimenzi of Yangtze River, the minimum content was found in Baiqing of Fujiang River. The content order of PAHs in the sediments followed Yangtze River (358.6 ng/g) > Minjiang River (322.2 ng/g) > Tuojiang River (292.7 ng/g) > Qujiang River (260.6 ng/g) > Jialing River (240.2 ng/g) > Fujiang River (82.4 ng/g). The vertical profiles of c(An)/c(An + Phe), c(FlA)/c(FlA + Pyr) and c(InP)/c (InP + BghiP) suggested the PAHs in this zone were mainly originated from pyrogenic source, the main sources of PAHs were petroleum combustion, biomass combustion, and coal burning. Risk assessment suggested that the PAHs in the sediment of this zone had no significantly biological impairment and low toxicological risk.

[Temporal distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons in sediment core from Miyun reservoir].

The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was measured in sediment core from Miyun reservoir, and the possible sources and the potential risk assessment also have been identified. The aim of the present work is to understand the temporal trend of PAHs in Miyun reservoir recently. The concentrations of sigma PAH16 in sediment ranged from 618.5 ng/g to 1087.9 ng/g, and roughly, increased continuously from the bottom (16 cm under the surface) to the surface sediment. The PAHs in sediment core were mainly composed of phenanthrene and fluorene. The concentrations of phenanthrene and fluorene in sediment core were 236.1-417.9 ng/g and 91-130.8 ng/g, respectively. Both of them accounted for 47.2%-58.1% of the sigma PAH16 in sediments. Nevertheless, high-rings aromatic hydrocarbons (5-6 rings) were increased steadily in recent years. PAHs compositional profile indicated that the main source of PAHs was originated from the combustion of coal and biomass. However, the vertical profiles of Flu/Flu + Pyr and INP/INP + BghiP ratios suggested that the vehicles emission was increased very recently. Risk assessment suggested that PAHs in sediment from Miyun reservoir was no significant biological impairment, and low toxicological risk of PAHs was found up to now.