Quantitative evaluation for the sources and aging processes of organic aerosols in urban Guangzhou: Insights from a comprehensive method of dual‑carbon isotopes and macro tracers

Fan Jiang; Junwen Liu; Zhineng Cheng; Ping Ding; Sanyuan Zhu; Xin Yuan; Wei Chen; Zhisheng Zhang; Zheng Zong; Chongguo Tian; Weiwei Hu; Junyu Zheng; Sönke Szidat; Jun Li; Gan Zhang

doi:10.1016/j.scitotenv.2023.164182

Quantitative evaluation for the sources and aging processes of organic aerosols in urban Guangzhou: Insights from a comprehensive method of dual‑carbon isotopes and macro tracers

Sci Total Environ. 2023 Aug 25:888:164182. doi: 10.1016/j.scitotenv.2023.164182. Epub 2023 May 16.

Authors

Fan Jiang¹, Junwen Liu², Zhineng Cheng³, Ping Ding⁴, Sanyuan Zhu³, Xin Yuan⁵, Wei Chen³, Zhisheng Zhang⁶, Zheng Zong⁷, Chongguo Tian⁷, Weiwei Hu³, Junyu Zheng⁵, Sönke Szidat⁸, Jun Li³, Gan Zhang³

Affiliations

¹ Institute for Environmental and Climate Research, Jinan University, Guangzhou, China; Department of Chemistry, Biochemistry and Pharmaceutical Sciences and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.
² Institute for Environmental and Climate Research, Jinan University, Guangzhou, China. Electronic address: liu.junwen@jnu.edu.cn.
³ State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, China.
⁴ State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, China.
⁵ Institute for Environmental and Climate Research, Jinan University, Guangzhou, China.
⁶ South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou, China.
⁷ Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
⁸ Department of Chemistry, Biochemistry and Pharmaceutical Sciences and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.

PMID: 37196948
DOI: 10.1016/j.scitotenv.2023.164182

Abstract

Organic carbon aerosol (OC) is a pivotal component of PM_2.5 in the atmospheric environment, yet its emission sources and atmospheric behaviors remain poorly constrained in many regions. In this study, a comprehensive method based on the combination of dual‑carbon isotopes (¹³C and ¹⁴C) and macro tracers was employed in the PRDAIO campaign performed in the megacity of Guangzhou, China. The ¹⁴C analysis showed that 60 ± 9 % of OC during the sampling campaign was associated with non-fossil sources such as biomass burning activities and biogenic emissions. It should be noted that this non-fossil contribution in OC would significantly decrease when the air masses came from the eastern cities. Overall, we found that non-fossil secondary OC (SOC_NF) was the largest contributor (39 ± 10 %) to OC, followed by fossil secondary OC (SOC_FF: 26 ± 5 %), fossil primary OC (POC_FF: 14 ± 6 %), biomass burning OC (OC_bb: 13 ± 6 %) and cooking OC (OC_ck: 8 ± 5 %). Also, we established the dynamic variation of ¹³C as a function of aged OC and the volatile organic compounds (VOCs) oxidized OC to explore the impact of aging processes on OC. Our pilot results showed that atmospheric aging was highly sensitive to the emission sources of seed OC particles, with a higher aging degree (86 ± 4 %) when more non-fossil OC particles were transferred from the northern PRD.

Keywords: Aging processes; Dual carbon isotopes; Organic carbon; Source apportionment.