| 上海市含碳大气颗粒物的粒径分布 |
| 摘要点击 2865 全文点击 2278 投稿时间：2012-08-17 修订日期：2012-10-24 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 颗粒物 OC EC 粒径分布 上海 |
| 英文关键词 aerosol particle organic carbon element carbon size distribution Shanghai |
|
| 中文摘要 |
| 使用STAPLEX大流量六级采样器(<0.49 μm、0.49~0.95 μm、0.95~1.5 μm、1.5~3.0 μm、3.0~7.2 μm和>7.2 μm),结合DRI Model 2001 热光碳分析仪(TOR),分析了2010年5月~2011年5月期间上海市嘉定区(市郊)、徐汇区(市区)的大气颗粒物样品中有机碳(OC)和元素碳(EC)的粒径分布. 结果表明,不同粒径的OC和EC质量浓度均呈双峰分布,较高峰出现于<0.49 μm粒径段,次高峰则出现于>3.0 μm的两个粒径段. 嘉定区(JD)和徐汇区(XH)PM3.0中OC的质量浓度分别为16.35μg·m-3和11.85μg·m-3,EC质量浓度分别为2.22μg·m-3和1.91μg·m-3,市郊大气颗粒物中碳组分质量浓度高于市区,说明市郊碳污染更为严重. 在<1.5 μm的粒径段,嘉定区OC与EC的同源性较好,表明其中大部分OC来自于燃烧源. 两地区不同粒径OC/EC值与不同排放源特征值的对比,可以说明徐汇区更多受到机动车尾气排放和道路扬尘的影响. 通过EC示踪法计算二次有机碳(SOC)质量浓度可知:上海市SOC质量浓度较高,PM3.0中达到6.76μg·m-3,占OC的质量分数为69%,粒径分布呈双峰分布,峰值位于0.49~0.95 μm和3.0~7.2 μm粒径段. |
| 英文摘要 |
| Using STAPLEX pumping system with a six-stage cascade impactor (size range: <0.49 μm, 0.49-0.95 μm, 0.95-1.5 μm, 1.5-3.0 μm, 3.0-7.2 μm,>7.2 μm), the atmospheric particulate samples at suburb (Jiading District) and urban (Xuhui District) sites in Shanghai, China were collected from May 2010 to May 2011. The organic carbon (OC) and the element carbon (EC) of those samples were analyzed by a DRI Model 2001 thermal/optical carbon analyzer with the reflectance (TOR) method. The size distributions of OC and EC in atmospheric particles both showed bimodal distributions at Jiading and Xuhui, with the peaks at size range of <0.49 μm. Meanwhile, the average annual concentrations of OC and EC in PM3.0were 16.35 μg·m-3 and 2.22 μg·m-3 at Jiading, 11.85 μg·m-3 and 1.91 μg·m-3 at Xuhui, respectively. The higher concentrations of particulate matters together with their carbonaceous species at the suburb site indicated that the particulate and carbonaceous aerosol pollution was more serious at suburb than at urban in Shanghai. Compared with Xuhui, the OC shared a higher homology with EC at <1.5 μm sizes at Jiading, which suggested that OC was mostly derived from combustion sources at urban site in Shanghai. Furthermore, the OC/EC mass ratios at various particulate sizes and those ratios of different sources were discussed. The result suggested that more vehicle emission and more road dust were present at Xuhui District. Moreover, the second organic carbon(SOC)were estimated using EC as a tracer of primary organic carbon, the SOC mass concentration in PM3.0 was 6.76μg·m-3 and had a proportion of 69% of OC in Shanghai, which also showed a bimodal distribution with peaks at size of 0.49-0.95 μm and 3.0-7.2 μm, respectively. |
|
|
|
