Seasonal variations, temperature dependence, and sources of size-resolved PM components in Nanjing, east China  

作　　者：Mingjie Xie Wei Feng Shuyan He Qin’geng Wang 

机构地区：[1]Collaborative Innovation Center of Atmospheric Environment and Equipment Technology,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China [2]State Key Laboratory of Pollution Control and Resources Reuse,School of the Environment,Nanjing University,Nanjing 210023,China

出　　处：《Journal of Environmental Sciences》2022年第11期175-186,共12页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China (No. 2016YFC0208504);the National Natural Science Foundation of China (Nos. 42177211, 41701551)。

摘　　要：Size-segregated ambient particulate matter(PM) samples were collected seasonally in suburban Nanjing of east China from 2016 to 2017 and chemically speciated. In both fine(< 2.1μm, PM2.1) and coarse(> 2.1 μm, PM>2.1) PM, organic carbon(OC) accounted for the highest fractions(26.9% ± 10.9% and 23.1% ± 9.35%) of all measured species, and NO3-lead in average concentrations of water-soluble inorganic ions(WSIIs). The size distributions of measured components were parameterized using geometric mean diameter(GMD). GMD values of NO_(3)^(-), Cl^(-), OC, and PM for the whole size range varied from < 2.1 μm in winter to > 2.1μm in warm seasons, which was due to the fact that the size distributions of semi-volatile components(e.g., NH4NO3, NH4Cl, and OC) had a dependency on the ambient temperature.Unlike OC, elemental carbon(EC), and elements, NH_(4)^(+), NO_(3)^(-), and SO_(4)^(2-)exhibited an increase trend in GMD values with relative humidity, indicating that the hygroscopic growth might also play a role in driving seasonal changes of PM size distributions. Positive matrix factorization was performed using compositional data of fine and coarse particles, respectively. The secondary formation of inorganic salts contributing to the majority(> 70%) of fine PM and 20.2% ± 19.9% of speciated coarse PM. The remaining coarse PM content was attributed to a variety of dust sources. Considering that coarse and fine PM had comparable mass concentrations, more attention should be paid to local dust emissions in future air quality plans.

关 键 词：Particulate matter Size distribution Seasonal variation Semi-volatility Source apportionment 

分 类 号：X513[环境科学与工程—环境工程]