| 西安市地表灰尘中多环芳烃分布特征与来源解析 |
| 摘要点击 2934 全文点击 1384 投稿时间：2015-09-15 修订日期：2015-11-24 |
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| 中文关键词 多环芳烃 分布 来源 地表灰尘 西安市 |
| 英文关键词 polycyclic aromatic hydrocarbons distribution source surface dust Xi'an City |
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| 中文摘要 |
| 采集了西安市地表灰尘样品58个,利用GC-FID对其中16种优控多环芳烃(PAHs)进行含量分析,在此基础上研究了其分布特征与环境来源. 结果表明,西安市地表灰尘中单体PAH的含量范围为14.69~6370.48 μg ·kg-1; 16种PAHs总量(Σ16PAHsΣ)范围为5039.67~47738.50 μg ·kg-1,平均值为13845.82 μg ·kg-1. 与国内外其他城市比较发现,西安市地表灰尘中PAHs的含量相对较高. 地表灰尘中PAHs主要由4环以上的高分子量PAHs构成,7种致癌芳烃(Σ7CPAHsΣ)平均占Σ16PAHsΣ的46.08%. 地表灰尘中Σ16PAHsΣ的平均含量在工业区最高,文教区、交通区和商业交通混合区含量次之,住宅区和公园较低. 地表灰尘中Σ16PAHsΣ平均含量沿主城区-二环-三环由内向外呈增加趋势. 地表灰尘中Σ16PAHsΣ在东郊和西郊工业区、南郊和北二环重交通区相对较高,主城区、北郊和城市东南部较低. 比值法、聚类分析和主成分分析结果表明,西安市地表灰尘中PAHs主要来源于化石燃料和煤的燃烧,其中柴油燃烧和汽油燃烧的方差贡献率分别为36.07%和32.31%,煤燃烧方差贡献率为23.40%. |
| 英文摘要 |
| A total of 58 surface dust samples were collected from Xi'an city. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography with a flame ionization detector (GC-FID). At the same time, the distribution and sources of PAHs in surface dust were studied. The results showed that the concentrations of individual PAH ranged from 14.69 to 6370.48 μg ·kg-1, and the total concentrations of 16 PAHs (Σ16PAHsΣ) ranged from 5039.67 to 47738.50 μg ·kg-1, with a mean of 13845.82 μg ·kg-1. Compared to the ΣPAHsΣ levels of other cities, the Σ16PAHsΣ in surface dust of Xi'an belonged to a relatively higher level. PAHs in surface dust were mainly dominated by high molecular weight PAHs with 4-6 rings and the concentration of 7 carcinogenic PAHs (Σ7CPAHsΣ) accounted for 46.08% of Σ16PAHsΣ. The mean of Σ16PAHsΣ in surface dust had the highest concentration at industrial area; followed by the educational area, traffic area, business and traffic area; residential area and parks showed relatively lower concentration. The average content of Σ16PAHsΣ in surface dust presented an increasing trend along the main urban area-the second ring road-the third ring road. Σ16PAHsΣ in surface dust had higher concentrations at the industrial areas of the east and west suburbs of Xi'an, the south suburb and the north section of the second ring road; Σ16PAHsΣ concentrations in the main urban area, north suburb and southeast part of Xi'an were relatively lower. The results of ratio, cluster analysis and principal component analysis showed that PAHs in surface dust were mainly originated from the combustion of fossil fuels and coal combustion. Among them, diesel combustion reached 36.07%, gasoline combustion accounted for 32.31%, and coal combustion was responsible for 23.40%. |
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