| 南京北郊大气颗粒物的粒径分布及其影响因素分析 |
| 摘要点击 2755 全文点击 1310 投稿时间：2015-05-07 修订日期：2016-04-25 |
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| 中文关键词 大气颗粒物 粒径分布 仪器对比 降水清除 霾天 吸湿增长 气团来源 |
| 英文关键词 aerosol particle size distribution comparison of samplers precipitation scavenging haze particle hygroscopic growth air mass sources |
| 作者 | 单位 | E-mail | | 吴丹 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | wudan_04@163.com | | 曹双 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | | | 汤莉莉 | 江苏省环境监测中心, 南京 210036 | | | 夏俊荣 | 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | | | 陆建刚 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | | | 刘刚 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | | | 杨孟 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | | | 李凤英 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | | | 盖鑫磊 | 南京信息工程大学江苏省大气环境与装备技术协同创新中心, 南京 210044
南京信息工程大学江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044 | |
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| 中文摘要 |
| 在南京北郊使用FA-3型9级采样器对2014年1～11月颗粒物的粒径分布进行了采样分析.首先将FA-3与中流量分级采样器（KC-120H）和环境保护局在线监测仪器的同期监测结果进行对比，数据相关系数均在0.95以上，对细粒子FA-3分别偏低13.9%和16.6%，而对PM10偏高15.2%和13.3%，但采样偏差在大气采样可接受范围之内，说明其可以对大气颗粒物进行准确分级和采样.南京北郊颗粒物污染严重，PM1.1，PM2.1和PM10的年平均浓度分别为（65.6±37.6）、（91.0±54.7）和（168.0±87.0）μg·m-3，污染以细粒子为主，且大部分在1.1 μm以下；颗粒物粒径呈双峰分布，峰值位于0.43～0.65 μm和9～10 μm粒径段；中值粒径为1.83 μm，为积聚模态污染.颗粒物粒径分布在冬季细粒径段较高，春季粗粒径段较高，夏季细粒径段降低并不明显，粗粒径段明显低于其他季节；颗粒物浓度的昼夜变化在粗粒径段差异很小，在细粒径段基本表现出夜晚大于白天的特征.除了夏季，降水对各个粒径范围的颗粒物都有清除作用，且在细粒径段表现得更为明显；霾发生时随着霾等级的加重，0.43～2.1 μm粒径段颗粒物浓度逐渐增加，该粒径段颗粒物质量浓度与能见度呈显著负相关.以相对湿度70%为界，颗粒物粒径分布发生了明显变化，湿度大于70%后，小于0.43 μm粒径段颗粒物质量浓度显著降低，而0.43～2.1 μm粒径段明显上升，颗粒物的吸湿增长应是主要原因.南京北郊的气团来源可以分为四类，其中西北方向快速输送的气团最为洁净，细粒径颗粒物浓度明显低于其它方向；本地和周边近距离输送的气团污染最重，粗细粒径颗粒物浓度都较高，其传输距离短，风速小，发生污染的概率最大，达到73.9%，对南京市的空气污染贡献较大. |
| 英文摘要 |
| The size distribution of particulate was analyzed by the FA-3 9 stage sampler in Northern-suburb of Nanjing from January to November in 2014. First, the monitoring result from FA-3 was compared with the results of the same period obtained from a medium flow size grading sampler (KC-120H) and online monitoring instrument of the Environmental Protection Agency. The data correlation coefficients were all greater than 0.95. The fine particle concentration from FA-3 was lower by 13.9% and 16.6%, while PM10 concentration was higher by 15.2% and 13.3% respectively. However, the deviations were in the acceptable range of atmospheric sampling which could indicate the accurate classification and sampling of particulate for FA-3. Particulate pollution in Northern-suburb Nanjing was serous in which the annual average concentrations of PM1.1, PM2.1 and PM10 were(65.6±37.6), (91.0±54.7) and (168.0±87.0) μg·m-3 respectively; fine particles dominated and most of them had a diameter of less than 1.1 μm. Particle size distribution was bimodal with peaks at 0.43-0.65 and 9-10 μm; the median diameter was 1.83 μm which was in the accumulation mode. In winter, the concentration of fine particle size was higher and in spring the coarse particle size was higher; in summer, the fine particle size concentration was not significantly reduced but coarse particle size was obviously lower than those in other seasons. The differences of particle size distribution in day and at night were very small in coarse segment and in fine segment, the nocturnal concentrations were mostly higher than diurnal concentrations. The precipitation had cleaning effect for each size range of particulate except in summer and the effect was more distinct in fine particle size. In haze days, with the aggravation of haze level, the particle concentration in the diameter range of 0.43-2.1 μm increased gradually while in this segment the particle concentration was significantly negatively correlated with visibility. Using relative humidity of 70% as the demarcation, the particle size distribution changed significantly:when humidity was greater than 70%, mass concentration of particle with a diameter of less than 0.43 μm reduced significantly but that with diameter range of 0.43-2.1 μm increased obviously which should be related to the particle hygroscopic growth. The air mass sources could be divided into four categories in northern-suburb of Nanjing. Air mass from the northwest with rapid transport velocity was the cleanest in which the fine particle size concentration was significantly lower than those in other directions; the air mass from local and surrounding was the most severely polluted with high concentrations in both fine and coarse segment, its transmission distance was short and wind speed was small which contributed greatly to air pollution of Nanjing with probability of occurrence of pollution reaching 73.9%. |
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