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You B, Zhang Z, Du A, Li Y, Sun J, Li Z, Chen C, Zhou W, Xu W, Lei L, Fu P, Hou S, Li P, Sun Y. Seasonal characterization of chemical and optical properties of water-soluble organic aerosol in Beijing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172508. [PMID: 38642752 DOI: 10.1016/j.scitotenv.2024.172508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/13/2024] [Accepted: 04/13/2024] [Indexed: 04/22/2024]
Abstract
Water-soluble organic aerosol (WSOA) plays a crucial role in altering radiative forcing and impacting human health. However, our understanding of the seasonal variations of WSOA in Chinese megacities after the three-year clean air action plan is limited. In this study, we analyzed PM2.5 filter samples collected over one year (2020-2021) in Beijing to characterize the seasonal changes in the chemical and optical properties of WSOA using an offline aerosol mass spectrometer along with spectroscopy techniques. The mean mass concentration of WSOA during the observation period was 8.84 ± 7.12 μg m-3, constituting approximately 64-67 % of OA. Our results indicate the contribution of secondary OA (SOA) increased by 13-28 % due to a substantial reduction in primary emissions after the clean air action plan. The composition of WSOA exhibited pronounced seasonal variations, with a predominant contribution from less oxidized SOA in summer (61 %) and primary OA originating from coal combustion and biomass burning during the heating season (34 %). The mass absorption efficiency of WSOA at 365 nm in winter was nearly twice that in summer, suggesting that WSOA from primary emissions possesses a stronger light-absorbing capability than SOA. On average, water-soluble brown carbon accounted for 33-48 % of total brown carbon absorption. Fluorescence analysis revealed humic-like substances as the most significant fluorescence component of WSOA, constituting 82 %. Furthermore, both absorption and fluorescence chromophores were associated with nitrogen-containing compounds, highlighting the role of nitrogen-containing species in influencing the optical properties of WSOA. The results are important for chemical transport models to accurately simulate the WSOA and its climate effects.
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Affiliation(s)
- Bo You
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiqiang Zhang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Aodong Du
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiaxing Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhijie Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chun Chen
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Zhou
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Weiqi Xu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Lu Lei
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Shengjie Hou
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ping Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
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Lei Y, Zhang K, Lu Y, Qin Y, Li L, Li J, Liu X, Wu C, Zhang S, Chen Y, Zhang J, Zhang F, Wang G. Characterization of water-soluble brown carbon in atmospheric fine particles over Xi'an, China: Implication of aqueous brown carbon formation from biomass burning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163442. [PMID: 37059143 DOI: 10.1016/j.scitotenv.2023.163442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/03/2023] [Accepted: 04/07/2023] [Indexed: 06/01/2023]
Abstract
Brown carbon (BrC) aerosols can affect not only the climate but also human health, however, the light absorption, chemical compositions, and formation mechanisms of BrC are still uncertain, which leads to uncertainties in the accurate estimation of its climate and health impacts. In this study, highly time - resolved brown carbon (BrC) in fine particles was investigated in Xi'an using offline aerosol mass spectrometer analysis. The light absorption coefficient (babs365) and mass absorption efficiency (MAE365) at 365 nm of water-soluble organic aerosol (WSOA) generally increased with oxygen-to-carbon (O/C) ratios, indicating that oxidized OA could have more impacts on BrC light absorption. Meanwhile, the light absorption appeared to increase generally with the increases of nitrogen-to-carbon (N/C) ratios and water-soluble organic nitrogen; strong correlations (R of 0.76 for CxHyNp+ and R of 0.78 for CxHyOzNp+) between babs365 and the N - containing organic ion families were observed, suggesting that the N - containing compounds are the effective BrC chromophores. babs365 correlated relatively well with BBOA (r of 0.74) and OOA (R of 0.57), but weakly correlated with CCOA (R of 0.33), indicating that BrC in Xi'an was likely to be associated with biomass burning and secondary sources. A multiple linear regression model was applied to apportion babs365 to contributions of different factors resolved from positive matrix factorization on water-soluble organic aerosols (OA) and obtained MAE365 values of different OA factors. We found that biomass-burning organic aerosol (BBOA) dominated the babs365 (48.3 %), followed by oxidized organic aerosol (OOA, 33.6 %) and coal combustion organic aerosol (CCOA, 18.1 %). We further observed that nitrogen-containing organic matter (i.e., CxHyNp+ and CxHyOzNp+) increased with the increase of OOA/WSOA and the decrease of BBOA/WSOA, especially under high ALWC conditions. Our work offered proper observation evidence that BBOA is oxidized through the aqueous formation to produce BrC in Xi'an, China.
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Affiliation(s)
- Yali Lei
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Ke Zhang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Yeyu Lu
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Yiming Qin
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
| | - Lijuan Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Jianjun Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Xiaodi Liu
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Can Wu
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Si Zhang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Yubao Chen
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Junke Zhang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Fan Zhang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Gehui Wang
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China; Institute of Eco-Chongming, East China Normal University, Shanghai 202162, China.
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Zhang T, Shen Z, Huang S, Lei Y, Zeng Y, Sun J, Zhang Q, Ho SSH, Xu H, Cao J. Optical properties, molecular characterizations, and oxidative potentials of different polarity levels of water-soluble organic matters in winter PM 2.5 in six China's megacities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 853:158600. [PMID: 36089047 DOI: 10.1016/j.scitotenv.2022.158600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/29/2022] [Accepted: 09/04/2022] [Indexed: 06/15/2023]
Abstract
Humic-like substances (HULIS) accounted for a great fraction of water-soluble organic matter (WSOM) in PM2.5, which efficiently absorb ultraviolet (UV) radiation and pose climate and health impacts. In this study, the molecular structure, optical properties, and oxidative potential (OP) of acid- and neutral-HULIS (denoted as HULIS-a, and HULIS-n, respectively), and high-polarity WSOM (HP-WSOM) were investigated in winter PM2.5 collected at six China's megacities. For both carbon levels and optical absorption coefficients (babs_365), HULIS-a/HULIS-n/HP-WSOM showed significant spatial differences. For each city, the carbon levels and babs_365 follow a similar order of HULIS-n > HULIS-a > HP-WSOM. Besides, the babs_365 of HULIS-n and HULIS-a showed the same order of Harbin > Beijing ≈ Wuhan > Xi'an > Guangzhou > Chengdu, while HP-WSOM exhibited an order of Wuhan > Chengdu > Xi'an > Harbin > Beijing > Guangzhou. Both HULIS-a and HULIS-n were abundant in aromatic and aliphatic compounds, whereas HP-WSOM was dominated by a carboxylic acid group. The OP (in unit of nmol H2O2 μg-1C) followed the order of HP-WSOM > HULIS-a > HULIS-n in all the cities. The OPs of HULIS-a, HULIS-n, and HP-WSOM in Harbin and Beijing were much higher than those of other cities, attributing to the high contribution from biomass burning. Highly positive correlations between reactive oxygen species (ROS) of HULIS-a and MAE365 were obtained in Chengdu, Wuhan, and Harbin, but ROS of HULIS-n had stronger correlation with MAE365 in Harbin, Chengdu, and Xi'an.
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Affiliation(s)
- Tian Zhang
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China; Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Zhenxing Shen
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China; Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
| | - Shasha Huang
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yali Lei
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yaling Zeng
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jian Sun
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qian Zhang
- Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Steven Sai Hang Ho
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, United States
| | - Hongmei Xu
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Junji Cao
- Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
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