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Impact of reduced anthropogenic emissions on chemical characteristics of urban aerosol by individual particle analysis
Li, Li1,4; Wang, Qiyuan1,2,3; Zhang, Yong1; Liu, Suixin1; Zhang, Ting1; Wang, Shuang1; Tian, Jie1; Chen, Yang5; Ho, Steven Sai Hang6; Han, Yongming1,2,3
2022-09-01
摘要A single particle aerosol mass spectrometer was deployed in a heavily polluted area of China during a corona virus lockdown to explore the impact of reduced anthropogenic emissions on the chemical composition, size distributions, mixing state, and secondary formation of urban aerosols. Ten particle groups were identified using an adaptive resonance network algorithm. Increased atmospheric oxidation during the lockdown period (LP) resulted in a 42.2%-54% increase in the major NaK-SN particle fraction relative to the normal period (NP). In contrast, EC-aged particles decreased from 31.5% (NP) to 23.7% (LP), possibly due to lower emissions from motor vehicles and coal combustion. The peak particle size diameter increased from 440 nm during the NP to 500 nm during LP due to secondary particle formation. High proportions of mixed (NO3-)-N-62 indicate extensive particle aging. Correlations between secondary organic ((C2H3O+)-C-43, oxalate) and secondary inorganic species ((NO3-)-N-62, 97HSO4- and (NH4+)-N-18) versus oxidants (O-x = O-3 + NO2) and relative humidity (RH) indicate that increased atmospheric oxidation promoted the generation of secondary species, while the effects of RH were more complex. Differences between the NP and LP show that reductions in primary emissions had a remarkable impact on the aerosol particles. This study provides new insights into the effects of pollution emissions on atmospheric reactions and the specific aerosol types in urban regions.
关键词COVID-19 Secondary formation Chemical characteristics Mixing state Individual particles
DOI10.1016/j.chemosphere.2022.135013
发表期刊CHEMOSPHERE
ISSN0045-6535
卷号303页码:11
通讯作者Wang, Qiyuan(wangqy@ieecas.cn) ; Cao, Junji(jjcao@mail.iap.ac.cn)
收录类别SCI
WOS记录号WOS:000813019400002
语种英语