珠江水体表层沉积物中PAHs的含量与来源研究

沿珠江白鹅潭水域及大学城官州河流域设立6个采样点,利用沉积物捕获器收集沉积物。参照美国EPA8000系列方法及质量保证和质量控制,对各采样点表层沉积物中16种多环芳烃（polycyclic aromatic hydrocarbons,PAHs）进行分析,以阐明珠江广州河段表层沉积物中PAHs的含量和分布特征,并结合特征化合物指数对其来源作初步探讨。珠江广州河段表层沉积物中PAHs总量介于4 787.5～8 665 ng·g^-1,平均值为7 078 ng·g^-1,黄沙码头河涌出口沉积物中总量为最高（8 665 ng·g^-1）,芳村码头为最低（4 787.5 ng·g^-1）。16种多环芳烃中菲、荧蒽、芘含量较高,分别占PAHs总量的16.11%、14.47%和17.77%。特征化合物荧蒽/202比值均小于0.5,茚并1,2,3-cd]芘/276比值均大于0.2,表明珠江广州段表层沉积物中PAHs主要来源于化石燃料的不完全燃烧。

Study on concentrations and sources of PAHs in the surface sediments from Pearl River

Sediment samples were collected in six sites which located in White Goose Pond of Pearl River and Guanzhou River in Guangzhou Higher Education Mega Center in Guangzhou,China using a sediment trap.Sixteen polycyclic aromatic hydrocarbons（PAHs） in the sediment sample were analyzed following the protocols in USEPA 8 000 serial methods.The total concentrations of PAHs in the sediment samples ranged from 4 790 to 8 660 ng·g^-1dry weight）,with an average of 7 080 ng·g^-1Sediment collected near Huangsha pier canal showed the highest PAH concentrations of 8 660 ng.g-1,while the lowest PAH concentrations of 4 790 ng.g-1 was observed in sediment collected near Fangcun pier canal.Phenanthrene,fluoranthene and pyrene were the most frequently detected PAHs,and they accounted for 16.1,14.5 and 17.8% of the total PAHs,respectively.Because the observed molecular indices fluoranthene/202 were over 0.5,and indeno1,2,3-cd ]pyrene/276 over 0.2 in all sediment samples,it can be concluded that the predominant source of PAHs in the sediments from Pearl River was incomplete combustion of fossil fuels.