| 摘要: |
| 于 2017年1、4、7、10月在南京市主城区采集了大气PM2.5样品，用BCR法对PM2.5中重金属进行连续提取，采用电感耦合等离子体-质谱法进行测定，分析重金属在颗粒物中不同形态和分布特征。结果表明，PM2.5中9种重金属质量比排序为：Fe>Zn>Pb>Mn>Cu>Cr>As>Ni>Cd。Zn、Pb、Cd、Cu、Mn、As主要分布在弱酸提取态；Ni在弱酸提取态、可氧化态和残渣态中分布较均匀，占比26%~37%；而Fe、Cr主要以残渣态存在，分布比例分别为71%和54%。PM2.5中Zn的生物有效性系数>0.8，属生物可利用性元素，表明其在环境中迁移能力最强，其余8种重金属生物有效性系数为0.2~0.8。 |
| 关键词: 南京 细颗粒物 重金属 化学形态 大气环境 |
| DOI： |
| 分类号:X823 |
| 文献标识码:B |
| 基金项目:南京市环保局环保科研基金资助项目（201604） |
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| Research on the Distribution Characteristics and Chemical Speciation of Heavy Metals in PM2.5 in Nanjing |
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LU Xi-hong，REN Lan，WU Li-juan
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Jiangsu Nanjing Environmental Monitoring Center，Nanjing,Jiangsu 210013，China
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| Abstract: |
| During January, April, July and October 2017, PM2.5 samples were collected at urban sites in Nanjing, while the distribution characteristics and chemical speciation of heavy metals were analyzed by BCR extraction and ICP-MS. The results showed that the heavy metal concents were ranked as: Fe＞Zn＞Pb＞Mn＞Cu＞Cr＞As＞Ni＞Cd. Zn, Pb, Cd, Cu, Mn and As in PM2.5 existed mainly in the acid-exchangeable species.The proportion of Ni in the acid-exchangeable species, oxidizable species and residual species were near, accounting from 26% to 37%. Approximately 71% of Fe and 54% of Cr existed in the residual species. The bioavailability coefficient (k) of Zn in PM2.5 were the highest, indicating the strongest migration ability in the environment, while the k values of other eight heavy metals ranged from 0.2 to 0.8. |
| Key words: Nanjing PM2.5 Heavy metal Chemical speciation Atmospheric environment |
