[Analysis on status pollution and variation of BTEX in Beijing].
[Analysis on status pollution and variation of BTEX in Beijing].
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发表时间：
2011-12
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通讯作者：
Jie Sun;Yue-si Wang;Fang-kun Wu
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作者：
Jie Sun;Yue-si Wang;Fang-kun Wu
采用浓度-气相色谱/质谱（CCD-GC/MS）两步法，对北京市2008-10年和2009-10年的环境BTEX浓度进行了分析，研究了BTEX的污染状况及其季节和日变化。北京市BTEX平均浓度为13.9 ~ 44.0 μ g x cm（-3）。主要化合物成分为甲苯、苯，其次为乙苯、间/对二甲苯、邻二甲苯。与国外城市和地区相比，北京大气BTEX水平相对较低。研究发现，北京地区BTEX主要来源于机动车尾气排放，煤炭和溶剂蒸发也是BTEX的重要来源。季节变化不明显，春季和夏季浓度最高，秋季浓度最低。排放源的季节变化是造成BTEX季节变化的主要原因。然而，天气因素对BTEX的影响也不容忽视，如温度和强风。观察到BTEX的显著日变化。BTEX浓度呈双峰型分布，在08:00 ~ 10:00达到峰值。在16点到8点之间。最低浓度一般出现在14:00左右。
In order to study the pollution status and the seasonal and diurnal variations, ambient concentrations of BTEX were analyzed at Beijing from 2008-10 to 2009-10, by using the method of two-step-concentration-gas spectrometry/mass (CCD-GC/MS). The average concentration of BTEX in Beijing was 13.9-44.0 microg x cm(-3). The dominant compound components were toluene, benzene, followed by ethyl benzene, m/p-xylene, o-xylene. Compared with foreign cities and regions, the level of BTEX at Beijing atmosphere was relatively lower. The study found that BTEX in Beijing mainly came from vehicle emissions, coal and solvent evaporation were also important sources of BTEX. No significantly obvious seasonal variation was observed, with the highest concentrations observed in spring and summer and the lowest concentrations generally found in autumn. Seasonal variations of emission sources were the main reason for seasonal changes of BTEX. However, the impact of weather factors on the BTEX can not be ignored, such as temperature and strong winds. Significant diurnal variations in BTEX were observed. The BTEX concentrations displayed a bimodal pattern, with peak between 08:00 and 10:00. and between 16:00 and 08:00. The minimum concentration generally appeared around 14:00.