东海表层沉积物中多环芳烃的分布特征及来源解析

本研究对东海沉积物中多环芳烃(PAHs)组成及含量进行了分析,发现多环芳烃总浓度为8.2~180.2 ng/g,和国内外其它区域相比,整体处于一个低至中等程度的污染水平。东海沉积物中PAHs的分布整体表现为中间低、两端高的格局。内陆架是长江入海物质的主要沉积区,也是PAHs的主要汇集区;陆架北部区域的物质来源复杂,但总体受长江入海泥沙的控制,自西向东PAHs含量梯度递减;研究区域的东北部,较高的PAHs可能源于济州岛的输入;冲绳海槽也含有较高PAHs;而残留沉积区中PAHs含量极低。通过多环芳烃组成特征判断,东海表层沉积物中PAHs主要来自煤、木材、油类的燃烧,还有部分来自油类的泄漏。同时不同区域Ba P/Be P、Ba A/Chry比值的差别表明内陆架及冲绳海槽的PAHs主要来自河流输送,残留沉积区的PAHs可能主要来自大气沉降。

Distribution and Sources of Polycyclic Aromatic Hydrocarbons in Surface Sediments from the East China Sea

Contents and compositions of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the East China Sea were determined. Results show that total PAHs concentrations varies from 8.2 ng/g to 180.2 ng/g, indicating a low to moderate level compared with that of the other regions worldwide. The distribution of PAHs contents in the sediments from the East China Sea also display that both ends are low, and the middle is high. Terrestrial particles from the Yangzi River were deposited into the inner shelf, where PAHs were mainly collected at the same time. The material sources in the northern continental shelf were complicated, and were primarily controlled by sediment transport from the Yangzi River, and PAHs contents decrease from west to east. Higher PAHs contents may be derived from Cheju Island in the northeast of the study area. Higher PAHs contents were found in the sediments from the Okinawa Trough, and lower PAHs contents existed in relict sediment. According to the PAH ratio index calculations, these PAH molecules were primarily derived from coal burning, biomass combustion and petroleum combustion, followed by oil spillage. Furthermore, the difference of BaP/BeP and BaA/Chry ratio in different areas indicate that PAHs in the inner shelf and the Okinawa Trough are derived from the river, and PAHs in relict sediment are from atmospheric deposition.