东海泥质区表层沉积物中多环芳烃的分布特征及物源

Distribution and source of polycyclic aromatic hydrocarbons in the surface sediments of the mud areas in the East China Sea

以GC/MSD内标法定量测定了东海近岸和远岸泥质沉积区18个表层沉积物中多环芳烃(PAHs)的含量,探讨了多环芳烃在这些泥质区的分布特征、影响因素及来源。结果显示,近岸泥质区多环芳烃含量普遍较高,介于180.3～424.8ng/g(干重)之间;冲绳海槽次之,含量为211.7ng/g;济州岛西南泥质区最低,含量介于117.1～211.7ng/g之间。东海泥质区多环芳烃的分布主要受控于离物源的远近、沉积物粒度、有机碳含量以及东海环流体系。东海泥质区的多环芳烃主要来源于热成因,大气干湿沉降和河流输入是其进入泥质区的主要途径。东海泥质区多环芳烃的污染程度中等。

Polycyclic aromatic hydrocarbons (PAHs) of 18 surface sediment samples from the mud areas of the East China Sea (ECS) were quantitatively analyzed by GC/MSD with the internal standard materials. The contents of PAHs in the coastal mud area are 180.3～424.8 ng/g (dry weight), the average content of which is the highest in the mud areas of the ECS; the content of PAHs in the Okinawa Trough is 211.7 ng/g; and the contents of PAHs in the mud area to the southwest of Cheju Island are 117.1～211.7 ng/g, the average content of which is the lowest in the study area. The distributional pattern of PAHs in the study area is controlled by the distance from their sources, grain sizes and TOC of surface sediments which are closely related with the circulation system of the ECS. The PAHs in the surface sediments are mainly pyrogenic. Atmospheric deposition and land runoff may be the important pathway of the input of PAHs to the sediments. The overall level of PAHs in the study area is moderate compared to the other areas including some estuaries, bays and shallow continental shelves.