南京北郊大气颗粒物的粒径分布及其影响因素分析  

Variation of Size Distribution and the Influencing Factors of Aerosol in Northern Suburbs of Nanjing

作　　者：吴丹[1,2] 曹双[1,2] 汤莉莉[3] 夏俊荣[4] 陆建刚[1,2] 刘刚[1,2] 杨孟[1,2] 李凤英[1,2] 盖鑫磊[1,2] 

机构地区：[1]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 [2]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 [3]江苏省环境监测中心,南京210036 [4]中国气象局气溶胶与云降水重点开放实验室,南京210044

出　　处：《环境科学》2016年第9期3268-3279,共12页Environmental Science

基　　金：江苏省自然科学基金项目(BK20130998);南京信息工程大学基金预研项目(2014x003);国家自然科学基金项目(41301581;91544220);江苏省普通高校研究生科研创新计划项目(KYLX-0857)

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1.1μm以下;颗粒物粒径呈双峰分布,峰值位于0.43～0.65μm和9～10μm粒径段;中值粒径为1.83μm,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,0.43～2.1μm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0.43μm粒径段颗粒物质量浓度显著降低,而0.43～2.1μm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.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. 1and PM10were（ 65. 6 ± 37. 6）,（ 91. 0 ± 54. 7） and（ 168. 0 ± 87. 0） μg·m^-3respectively; 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 particulateexcept 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

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 

分 类 号：X513[环境科学与工程—环境工程]