【作者】 李春雷； 傅家谟； 盛国英；

【Author】 LI Chun-lei, FU Jia-mo, SHENG Guo-ying (Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China)

【机构】 复旦大学环境科学与工程系； 中国科学院广州地球化学研究所有机地球化学国家重点实验室；

【摘要】 广州地区冬季大气中PCBs空间分布的研究结果表明,空气中PCBs的总量按照距离市区从近到远浓度依次降低。市区的平均浓度是郊区的1．61倍,是背景区的2．54倍。PCBs各单体化合物的浓度分布表现出明显的地区差异。低氯取代PCBs的市区浓度比郊区和背景区的浓度高出很多,而高氯取代PCBs的空间差异不明显。不同氯数PCB浓度之和对PCBs总量的百份贡献率分布中,市区、郊区和背景区都表现为三氯和四氯的贡献最大,而且两者的贡献率之和非常接近。市区和郊区空气中三氯和四氯的贡献比较接近,而背景区空气中四氯的贡献高达52．79％, 是三氯贡献的近两倍。郊区和背景区空气中五氯取代PCBs的平均贡献率分别是9．659／0和10．87％。仅就颗粒相而言,它的平均贡献率在市区、郊区和背景区表现出非常好的一致性。市区、郊区和背景区空气中log Kp vs log PLo线性相关的斜率mr分别是-0．60、-0．42和-0．45,都明显地偏离空气中气／固分配的理想平衡状态。更多还原

【Abstract】 The spatial distribution of atmospheric PCBs in hiemal Guangzhou were studied. The result indicated that the winter concentrations of atmospheric PCBs decreased in the order of urban, suburban and background. The average PCBs concentration in urban area was 1.61 times as that in suburban, 2.54 times as that in background. The PCB homologue concentrations were geographically different among urban, suburban and background. The concentrations of lower chlorinated congeners in urban atmosphere were much higher than those in suburban and background atmosphere, while for the higher chlorinated congeners, the spatial difference was not significant. With respect to the spatial distribution of PCB homologues, tri- and tetra-CBs were identified as the main components. The summed contributions of these two components were similar among the three areas, with values of 77.21%, 77.19%, and 81.10%. The percentages of tri- and tetra-CBs were similar in the urban and suburban atmosphere, while in the background atmosphere, the percentage of tetra-CBs was nearly two times as that of tri-CBs, with value of 52.79%. The average contributions of penta-CBs to the total atmospheric PCBs were similar between suburban and background area, with values of 9.65% and 10.87%. Taking only particulate PCBs into account, the percentages of penta-CBs were well consistent among urban, suburban and background area, with values of 15.20%, 16.23%, and 15.87%. The slopes of log Kp versus log PLo were -0.60, -0.42 and -0.45 for urban, suburban and background, respectively, which was larger (shallower) than the expected theoretical value of-1.更多还原