Study on Concentrations and Sources of PAHs in the Surface Sediments from Pearl River

Six sites were set up along water areas of the White Goose Pond of Pearl River and the Guanzhou River in Guangzhou Higher Education Mega Center. The surface sediments were obtained by using a sediment trap. The concentrations of 16 kinds of polycyclic aromatic hydrocarbons(PAHs) in the sediments from Pearl River were analyzed, based on the USEPA 8000 serial methods, and under quality assurance and quality control (QA/AC). The objectives of this study were 1) to identify the contents and its spatial variations of PAHs in the surface sediments from Pearl River in Guangzhou; 2) and to explain the sources preliminarily, based on the molecular marker indices of PAHs. The results showed that the total concentrations of PAHs in the sediments ranged from 4790 to 8660 ng·g^-1 (dry weight), with an average of 7080 ng·g^-1. The highest content of PAHs was 8660 ng·g^-1 observed near Huangsha pier canal, while the lowest was 4790 ng·g^-1 observed near Fangcun pier canal. In all kinds of PAHs detected, the concentrations of phenanthrene, fluoranthene, pyrene were relatively higher, accounted for 16.1% , 14.5% and 17.8%, respectively. According to the observed molecular indices fluoranthene/202 which were over 0.5 in all sediment samples, and indeno[1, 2, 3-cd ]pyrene/276 all over 0.2, it can be concluded that the predominant source of PAHs in the sediments from Pearl River was incomplete combustion of fossil fuels.