| 利用SPAMS研究华北乡村站点(曲周)夏季大气单颗粒物老化与混合状态 |
| 摘要点击 4468 全文点击 1779 投稿时间：2015-08-19 修订日期：2015-11-03 |
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| 中文关键词 单颗粒 化学组成 粒径 混合状态 单颗粒气溶胶飞行时间质谱(SPAMS) |
| 英文关键词 single particle aerosol composition particle size mixing state single particle aerosol mass spectrometry(SPAMS) |
| 作者 | 单位 | E-mail | | 黄子龙 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点实验室, 北京 100871 | 906264663@qq.com | | 曾立民 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点实验室, 北京 100871 | lmzeng@pku.edu.cn | | 董华斌 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点实验室, 北京 100871
中国科学院大气物理研究所大气边界层和大气化学国家重点实验室, 北京 100029 | | | 李梅 | 广州禾信分析仪器有限公司, 广州 510530 | | | 朱彤 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点实验室, 北京 100871 | |
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| 中文摘要 |
| 利用单颗粒气溶胶飞行时间质谱(SPAMS)于 2013年6月30日~7月8日对华北地区乡村站点曲周大气单颗粒粒径及其化学组成进行了在线测量,共采集到同时含有正负离子谱图的颗粒230152个,其粒径主要集中在 0.2~2.0 μm. 结果表明,该地区的大气颗粒物主要分为8类:元素碳 (EC, 55.5%)、有机碳 (OC, 10.7%)、钠,钾等碱金属颗粒 (alkalis, 17.4%)、其他金属颗粒 (other metals, 1.7%)、富铁颗粒 (Fe-rich, 6.3%)、富铅颗粒物 (Pb-rich, 3.1%)、沙尘颗粒 (dust, 4.8%), other颗粒(0.8%),观测得到的8类气溶胶颗粒中绝大部分包含46NO2-、62NO3-、80SO3-、96SO4-、97HSO4-等二次组分离子,说明这些颗粒都经历了不同的老化过程或与二次组分进行了不同程度的混合. 从气溶胶类型的谱分布看,各类型颗粒数浓度峰值基本出现 在700~800 nm之间, dust、Fe颗粒主要集中在粗粒径段, EC颗粒子类研究表明随着表面不断吸附 NH4+、NO3-、SO42-等二次组分, EC颗粒逐步演化成老化程度较低的 NO3-吸附型EC(ECN)和严重老化的SO42-吸附型EC(ECS)混合态,两者日变化呈现明显的负相关性,也可能随着二次有机物在 EC表面吸附,形成 OC/EC混合态. |
| 英文摘要 |
| To characterize the size distribution and chemical compositions of ambient particles at an agriculture site in the North of Chinese Plain, a single particle aerosol mass spectrometer (SPAMS) was deployed from June 30 to July 8, 2013. A total of 230152 particles in the size range of 0.2-2.0 μm were chemically analyzed with both positive and negative ion spectra. The results revealed that aerosol could be classified into eight dominant groups, including elemental carbon (EC, 55.5%),organic carbon (OC, 10.7%),alkalis (Na-K, 17.4%),other metals(1.7%),Fe-rich(6.3%),Pb-rich(3.1%),dust(4.8%), and other(0.8%). The observed eight types of particles contained secondary components such as 46 NO2-,62NO3-,80 SO3-,96 SO4-,97 HSO4-, showing that they probably went through different aging processes. The analysis of particle size distribution showed that 700-800 nm was the peak value of all particles, and that dust and Fe particles were mainly in the coarse size range. EC particles subtype group research revealed EC particles tended to be aging with the above mentioned secondary ions and eventually led to a particle type conversion from EC to the less aging ECN and the more serious aging ECS, the diurnal variation of which was obviously negatively correlated, and there was a possibility of forming OC/EC mixture with the adsorption of secondary organic matter on EC surface. |
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