| 北京冬季PM2.5中金属元素浓度特征和来源分析 |
| 摘要点击 3685 全文点击 1072 投稿时间：2016-07-21 修订日期：2016-10-20 |
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| 中文关键词 PM2.5 金属元素 富集因子 因子分析 北京 |
| 英文关键词 PM2.5 metal elements enrichment factor factor analysis Beijing |
| 作者 | 单位 | E-mail | | 乔宝文 | 北京化工大学环境科学与工程系, 北京 100029
中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | qiaobaowen@dq.cern.ac.cn | | 刘子锐 | 中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | | | 胡波 | 中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | | | 刘景云 | 北京化工大学环境科学与工程系, 北京 100029
中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | | | 逄妮妮 | 北京化工大学环境科学与工程系, 北京 100029
中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | | | 吴方堃 | 中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | | | 徐仲均 | 北京化工大学环境科学与工程系, 北京 100029 | xuzj@mail.buct.edu.cn | | 王跃思 | 中国科学院大气物理研究所, 大气边界层物理和大气化学国家重点实验室, 北京 100029 | |
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| 中文摘要 |
| 为了解北京冬季细颗粒物中金属元素的浓度水平及其来源，于2014年12月至2015年1月使用中流量PM2.5采样器在北京城区开展了为期30 d的连续采样，采用滤膜称重法检测PM2.5浓度，电感耦合等离子体质谱法（ICP-MS）分析PM2.5中16种元素总量，并采用富集因子法和因子分析法分析元素污染特征及其来源.结果表明，观测期间PM2.5中主要金属元素为K、Ca、Fe、Al和Mg，占16种元素总量的90.7%.与白天相比，地壳元素如Mg和Al等在夜间的浓度下降30%以上，而人为源金属元素如Cu和Pb等的浓度则上升40%以上.从优良天到重污染天气，上述16种金属元素的总浓度上升1倍，但其在PM2.5中的比例却逐渐降低，说明金属元素的富集不是PM2.5上升的主要原因.随着污染程度的加剧，Cu、Zn、As、Se、Ag和Cd等主要来自人为源的金属元素浓度上升较快，重度污染天与优良天的浓度比值范围为2.9~5.3；而Al、Mg、Ca、Mn和Fe等地壳元素浓度上升则较缓，重度污染天与优良天的浓度比值范围为1.2~1.8.北京冬季PM2.5中金属元素主要来源于燃煤和生物质燃烧、交通和工业排放以及地面扬尘，贡献率分别为34.2%、25.5%和17.1%. |
| 英文摘要 |
| To study the characteristics and sources of trace metals in PM2.5 during wintertime in Beijing, PM2.5 samples were collected from December 2014 to January 2015 by a middle volume sampler in the urban area of Beijing for 30 consecutive days. The mass concentration of PM2.5 was measured by filter membrane weighting method, and 16 kinds of trace metals were determined by inductively couple plasma-mass spectrometry (ICP-MS). In addition, the pollution characteristics and sources of trace metals were analyzed by enrichment factor (EF) method and factor analysis, respectively. The results showed that the concentrations of five elements (i. e. K, Ca, Fe, Al and Mg) accounted for 90.7% of the total metal elements. The concentrations of the metal elements changed obviously between day and night. Compared with daytime, crustal elements like Mg and Al decreased by more than 30% while anthropogenic elements like Cu and Pb increased by more than 40% in nighttime. Although the concentrations of metal elements increased by nearly one time in heavy pollution days compared with clean days, the mass percent of which in PM2.5 decreased from 10.9% in clean days to 4.6% in heavy pollution days. This result suggested the accumulation of metal elements in heavy pollution days had a minor contribution to the increased mass concentration of PM2.5. As the pollution episode progressed, anthropogenic elements (Cu,Zn,As,Se,Ag and Cd) increased faster than crustal elements (Al,Mg,Ca,Mn and Fe), which showed ratios ranging from 2.9 to 5.3 for anthropogenic elements and ratios ranging from 1.2 to 1.8 for crustal elements, when compared between heavy pollution days and clean days. In addition, the EF value of anthropogenic elements was also increased in the pollution days, indicating the concentrations of these elements was further influenced by the anthropogenic sources. Factor analysis showed that metal elements of PM2.5 during wintertime of Beijing were mainly from coal combustion and biomass burning, motor vehicle and industry emissions, and re-suspension of road dust, with the contributions of 34.2%,25.5% and 17.1%, respectively. |
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