Particle size distribution and gas–particle partitioning of polychlorinated biphenyls in the atmosphere in Beijing, China

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• 作者：Qingqing Zhu ; Minghui Zheng ; Guorui Liu…
• 关键词：Polychlorinated biphenyls ; Urban pollution ; Atmospheric pollution ; Particulate matter ; Gas–particle partitioning ; Size distribution
• 刊名：Environmental Science and Pollution Research
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：24
• 期：2
• 页码：1389-1396
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment, general; Environmental Chemistry; Ecotoxicology; Environmental Health; Atmospheric Protection/Air Quality Control/Air Pollution; Waste Water Technology / Water Pollution Control / Water M
• 出版者：Springer Berlin Heidelberg
• ISSN：1614-7499
• 卷排序：24

文摘

Size-fractionated samples of urban particulate matter (PM; ≤1.0, 1.0–2.5, 2.5–10, and >10 μm) and gaseous samples were simultaneously obtained to study the distribution of polychlorinated biphenyls (PCBs) in the atmosphere in Beijing, China. Most recent investigations focused on the analysis of gaseous PCBs, and much less attention has been paid to the occurrence of PCBs among different PM fractions. In the present study, the gas–particle partitioning and size-specific distribution of PCBs in atmosphere were investigated. The total concentrations (gas + particle phase fractions) of Σ₁₂ dioxin-like PCBs, Σ₇ indicator PCBs, and ΣPCBs were 1.68, 42.1, and 345 pg/m3, respectively. PCBs were predominantly in the gas phase (86.8–99.0 % of the total concentrations). The gas–particle partition coefficients (K_p) of PCBs were found to be a significant linear correlated with the subcooled liquid vapor pressures (P_L0) (R2 = 0.83, P < 0.01). The slope (m_r) implied that the gas–particle partitioning of PCBs was affected both by the mechanisms of adsorption and absorption. In addition, the concentrations of PCBs increased as the particle size decreased (>10, 2.5–10, 1.0–2.5, and ≤1.0 μm), with most of the PCBs contained in the fraction of ≤1.0 μm (53.4 % of the total particulate concentrations). Tetra-CBs were the main homolog in the air samples in the gas phase and PM fractions, followed by tri-CBs. This work will contribute to the knowledge of PCBs among different PM fractions and fill the gap of the size distribution of particle-bound dioxin-like PCBs in the air.