1. Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
Abstract:In order to identify the characteristics of the particle effective density in Shenzhen and the influencing factors, we used a centrifugal particle mass analyzer (CPMA) combined with a differential mobility analyzer (DMA) to simultaneously measure the size-resolved effective density of particles of 50to 500nm at an urban site from September 2020 to February 2021. The median effective density ranged from 1.29 to 1.53g/cm3, increasing with the particle diameter, and the effective density in autumn was slightly lower than that in winter. During the clean period, the effective density of particles was low and a bimodal distribution was observed. The median effective density of a low-density mode was in the range of 0.70~0.80g/cm3, indicating the presence of fresh soot particles. While the median effective density of a high-density mode was in the range of 1.3~1.5g/cm3, which was between the material densities of secondary inorganic particles and organic particles, indicating mixing of them. During the polluted period, the effective density at different particle sizes increased and showed a unimodal distribution, which was a result of internal mixing. In the event of new particle formation, nitrate condensation was found to be the main reason for the subsequent increase in particle size and effective density.
郑锦怡, 彭妍, 魏静, 郭松, 何凌燕, 黄晓锋. 深圳市大气颗粒物分粒径有效密度及影响因素[J]. 中国环境科学, 2022, 42(4): 1526-1533.
ZHENG Jin-yi, PENG Yan, WEI Jing, GUO Song, HE Ling-yan, HUANG Xiao-feng. Study on effective density of size-resolved particles and the influencing factors in Shenzhen. CHINA ENVIRONMENTAL SCIENCECE, 2022, 42(4): 1526-1533.
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