| 上海市浦东城区二次气溶胶生成的估算 |
| 摘要点击 4599 全文点击 2722 投稿时间：2012-08-07 修订日期：2012-11-06 |
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| 中文关键词 二次气溶胶 光化学反应 臭氧 气溶胶组分 |
| 英文关键词 secondary aerosol photochemical reaction ozone chemical composition |
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| 中文摘要 |
| 利用2010年5~10月不同日最高O3小时浓度(O3,max)下PM10浓度变化评估不同O3浓度水平下二次气溶胶生成量. CO作为一次颗粒物的标志物,O3作为光化学反应水平的指示物种. 结果表明不同光化学水平条件下, PM10中一次与二次气溶胶浓度及比例存在较大差异. 随着光化学水平的增加, PM10中一次气溶胶排放浓度增长不大(0.036~0.044 mg·m-3),二次气溶胶的生成量却呈数倍增长(0.018~0.055 mg·m-3); 二次与一次气溶胶浓度的比例也从49.8%增加到 124.5%. O3,max出现的时间也随着光化学水平的增强由13:00推迟到14:00,二次气溶胶生成的主要时段也从11:00~20:00增加到09:00~20:00; 此外,PM2.5中主要组分SO42-、NO3-、OC等比例随着光化学水平(即O3,max浓度)的不同而存在一定差异,当O3,max<0.10 mg·m-3时,PM2.5主要由 12.0%有机碳(OC)、18.7%硫酸盐、13.1%硝酸盐和4.5%元素碳(EC)组成,而O3,max>0.20 mg·m-3时,PM2.5主要由20.0 %有机碳(OC)、22.9%硫酸盐、23.1%硝酸盐和4.7%元素碳(EC)组成. 说明SO42-、NO3-、OC受光化学水平影响较大. |
| 英文摘要 |
| Analyses of diurnal patterns of PM10 in the downtown of Pudong, Shanghai have been performed in this study at different daily ozone maximum concentrations (O3,max) from May to October, 2010. In order to evaluate secondary aerosol formation at different ozone levels, CO was used as a tracer for primary aerosol, and O3,max was used as an index for photochemical activity. Results show that along with increasing of O3 concentration, the concentration of primary and secondary aerosol was increased respectively from 0.036 to 0.044 mg·m-3 and from 0.018 to 0.055 mg·m-3. The ratio of secondary to primary aerosol was increased from 49.8% to 124.5%. Furthermore, along with the increase of O3,max the forming time of O3,max and secondary aerosol was changed respectively from 13:00 to 14:00 and from 11:00-20:00 to 09:00-20:00. At the same time, the chemical composition of PM2.5 was different at different photochemical levels. PM2.5 was composed of 12.0% organic carbon (OC), 18.7% sulfate (SO42-), 13.1% nitrate (NO3-) and 4.5% element carbon (EC) when O3,max was <0.10 mg·m-3 and PM2.5 was composed of 20.0% organic carbon (OC), 22.9% sulfate, 23.1% nitrate and 4.7% element carbon (EC) with O3,max>0.20 mg·m-3. These results approved that the photochemical reactivity promoted the production of SO42-, NO3- and OC. |
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