DISTRIBUTION AND TRANSPORTATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SUSPENDED PARTICULATE MATTER AND SURFACE SEDIMENT FROM THE PEARL RIVER ESTUARY

Abstract

ABSTRACT Based on the quantitative and qualitative analysis of sixteen Polycyclic Aromatic Hydrocarbons (PAHs) with GC and GC-MSD, the concentrate distribution and transportation characteristics of PAHs in suspended particulate matter (SPM) and surface sediments (SS) from the Pearl River Estuary were studied. Whether in SPM or in SS, the concentration distribution of PAHs were characterized by acenaphthene (mean 55.5 µg/g in SPM, 226 ng/g in SS) with subordinate amounts of the tri- and tetra-cycle PAHs such as fluorene, fluoranthene, phenaphene and pyrene. However, PAHs had different composition and concentration in SPM and SS. Pentacyclic PAHs appeared in SS and seldom in SPM because of their low solubility and high molecular weight. The concentrations of the tri-, tetracyclic PAHs in SPM were 100–300 times higher than those in SS. The total PAHs varied from 12–281 µg/g (mean 77 µg/g) in SPM and 208–1849 ng/g (mean 537 ng/g) in SS respectively. There were similar correlations between the concentrations of PAHs in SPM and salinity, and between the distance of the stations from the river outlet moving seawards and the concentrations of PAHs. These indicated that PAHs were degraded or transported along with the salinity gradient in SPM and the distance from the river outlet in SS. It was also suggested that the sources of these PAHs are from sewage and shipping discharge-pollutants. Pearl River Estuary had been lightly contaminated by PAHs.