渤海表层沉积物中多环芳烃的分布与生态风险评价

Distribution and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments from Bohai Sea, China

利用第2次全国海洋污染基线调查数据,研究渤海表层沉积物中多环芳烃(PAHs)的空间分布特征和输入来源.结果表明,按渤海海区划分,PAHs含量由高至低依次为秦皇岛沿岸、辽东湾、莱州湾、辽东半岛近岸、外海海区和渤海湾近岸.对照有关的沉积物质量标志水平,秦皇岛沿岸和辽东湾(尤其是锦州湾)表层沉积物中PAHs具有较高生态风险.就PAHs组成而言,锦州湾近岸沉积物中低环比例较高,其它海区4～5环占优.荧蒽 芘和芘 苯并(a)芘两个比值参数显示锦州湾近岸沉积物的PAHs主要源于石油工业,秦皇岛近岸和莱州湾部分站点主要来自燃油产物,而其它海区的大部分站点则属于燃煤型来源.燃烧生成的PAHs易吸附于细微颗粒物上,其迁移和沉降可能是外海海区PAHs含量高于渤海湾近岸的一个原因.

By using the data of the Second Survey of Marine Pollution Baseline, the spatial distribution and main sources of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments from BoHai Sea were investigated. The results showed that the concentration of total PAHs from high to low were the coastal area at Qinhuangdao, Liaodong Bay, Laizhou Bay, the costal area at Liaodong Peninsula, the outer sea area and the coastal area at Bohai Bay. Compared with the corresponding quality guidelines, Qinhuangdao and Liaodong Bay would have stronger ecological risk. As to the compositions of parent PAHs, The proportion of the low molecular components at Jinzhou Bay was high, while the components with 4 or 5 rings were dominant in other areas. Based on Fluoranthene/Pyrene and Pyrene/Benzo(a)pyrene ratios, the main source of PAHs was identified from petroleum industry at Jinzhou Bay, petrolic combustion turned into the source in Qinhuangdao and part of Liaodong Bay, and coal-burning was primary in the other areas. The reason why the concentrations of PAHs in the outer sea area were higher than inshore sea in Bohai Bay was probably the adsorption of PAHs originated from fossil fuel combustion on fine particles followed by transfer and deposition.