[Characteristics and sources of polycyclic aromatic hydrocarbons in surface soil from chemical industrial areas]

Concentrations and composition of 16 polycyclic aromatic hydrocarbons (PAHs) listed for prior control by US EPA were detected by analyzing 28 surface soil samples from the chemical industrial areas of Tianjin Binhai New Area with a gas chromatography equipped with mass spectrometry (GC/MS). Relative concentrations of PAH compounds with different benzene rings and principal component analysis were used to identify the possible sources of soil PAHs. The maximum PAH concentration in all the samples was 5,991.7 ng x g(-1), with a mean values of 1,185.0 ng x g(-1). The concentrations of four and five rings PAH components were higher than that of the other PAH components in Tanggu and Hangu chemical industrial areas, and three rings PAH components were major PAHs in Dagang petroleum industrial area. There is significant positive correlation (n = 28, R2 = 0.847, p0.01) between PAH concentrations and total organic carbon (TOC) contents in the soil samples. Coal combustion was the dominant source of PAHs in chemical industrial areas, while petroleum volatilization and leakage were main contributors of PAHs in Dagang petroleum industrial area.