中国东海水体中多氯联苯的浓度及其组成特征

东海由于受到长江和闽浙沿岸工业污水输入以及电子垃圾处理场排放的影响，被认为是多氯联苯重污染区域。本研究利用"科学三号"科学考察船，于2012年10月执行的东海航次期间，从中国东海不同区域采集到11个表层水样，测定其中溶解态多氯联苯的浓度。中国东海水体中多氯联苯浓度为（0.59~1.68）ng/L，相比国内外海域，属于中低等水平。研究结果表明，海水多氯联苯浓度和盐度之间存在显著负相关性，说明沿岸河流冲淡水搬运的多氯联苯是东海水体中多氯联苯的重要来源；此外其组成以三氯，四氯和五氯为主，这与我国历史上多氯联苯的使用情况吻合。通过水体中不同氯代化合物浓度和对应K_OW理论浓度值的比较发现，两者之间整体吻合较好，表明化合物的物理化学属性是控制其在水体中浓度的重要因素。然而，东海近岸水体中六氯联苯污染程度略高于理论浓度值，这一潜在的污染来源可能和东海沿岸省市电子垃圾处理场有关。

Concentration and composition of polychlorinated biphenyls in the water of the East China Sea

The East China Sea (ECS) is considered a heavily polluted area of polychlorinated biphenyls (PCBs) due to the input of industrial wastewater from the Yangtze River, Fujian and Zhejiang coastal runoff and emissions from adjacent e-waste disposal sites.In this study, eleven surface water samples were collected from the ECS to determine the occurrence of PCBs in the seawater by the "Science Ⅲ" scientific research ship during October 2012.The PCB concentrations of the water from ECS ranged from 0.59 to 1.68 ng/L, and the values were at a middle-low level compared with other studying areas.There was a significant negative correlation between concentration of PCBs and salinity, indicating that the coastal runoff was an important way for PCBs transport in the ECS.The profile of PCB homologues was dominated by less chlorinated compounds, i.e.tri-PCBs, tetra-PCBs and penta-PCBs, which related to the historical production and usage of PCBs in china.The concentrations of different PCB congeners were consistent with the theoretical ones which obtained from the Kow values, indicating the physicochemical properties was an important factor affecting the occurrence of PCBs in the water.Besides, a relatively higher abundance of hexa-PCBs was observed in the seawater from the ECS, hinting that the e-wastes treatment emissions from coastal areas might be a potential source.