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| 摘要: |
| 于 2017年1、4、7、10月在南京市主城区采集了大气PM<sub>2.5</sub>样品，用BCR法对PM<sub>2.5</sub>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，PM<sub>2.5</sub>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%。PM<sub>2.5</sub>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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| Abstract: |
| During January, April, July and October 2017, PM<sub>2.5</sub> 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 PM<sub>2.5</sub> 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 PM<sub>2.5</sub> 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 |
