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Ma H, Liu D, Deng J, Zhao J, Zhang Q, Zhang Z, Hu W, Wu L, Fu P. Compositions and sources of fluorescent water-soluble and water-insoluble organic aerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174627. [PMID: 38986712 DOI: 10.1016/j.scitotenv.2024.174627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2024] [Revised: 07/06/2024] [Accepted: 07/07/2024] [Indexed: 07/12/2024]
Abstract
Brown carbon (BrC), the light-absorbing component of organic aerosols, plays a significant role in climate change and atmospheric photochemistry. However, the water-insoluble fractions of BrC have not been extensively studied, limiting the assessment of the overall climate effects of BrC. In this study, water-soluble and -insoluble organic carbon (i.e., WSOC and WIOC) in wintertime aerosols in Hefei were subsequently fractionated, and their fluorescence properties were comparatively investigated with the excitation-emission matrix method. WIOC contributing 57.1 % was the major component of organic carbon. WSOC with the largest contribution from humic-like regions exhibited a redshift compared to WIOC. Three humic-like substances (HULIS) with different oxidation degrees and one protein-like substances (PRLIS) were identified as the major fluorescent components by the parallel factor analysis. WSOC had more highly oxygenated HULIS, whereas low-oxygenated HULIS dominated WIOC. Nighttime WIOC contained more less-oxygenated species. The positive matrix factorization analysis suggested that biomass burning (43 %) was the largest source of both fluorescent WSOC and WIOC. Coal combustion contributed much more to fluorescent WIOC (40 %), whereas secondary formation contributed more to fluorescent WSOC (12 %). During aerosol pollution episodes, the increase in fluorescence efficiency was much greater for WIOC (25 %) than for WSOC (12 %), and WSOC and WIOC experienced a redshift and blueshift in emission wavelength, respectively. WSOC had more highly oxygenated HULIS, while WIOC had more less-oxygenated HULIS in aerosol episodes than the non-episodic periods. In addition, aerosol pollution was accompanied by the increased contributions of biomass burning and coal combustion to both fluorescent WSOC and WIOC, while the decreased relative contribution of secondary formation to fluorescent WSOC. Our findings highlighted the different fluorescence properties, compositions and sources of fluorescent WSOC and WIOC, providing a comprehensive view of BrC aerosols.
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Affiliation(s)
- Hao Ma
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Dandan Liu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Junjun Deng
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
| | - Jiaming Zhao
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Qiang Zhang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Zhimin Zhang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China; School of Material Engineering, Shanxi College of Technology, Shuozhou 036000, China
| | - Wei Hu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Libin Wu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
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2
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Zhang P, Du B, Xu J, Wang J, Liu Z, Liu B, Meng F, Tong Z. Identification and Removal of Pollen Spectral Interference in the Classification of Hazardous Substances Based on Excitation Emission Matrix Fluorescence Spectroscopy. Molecules 2024; 29:3132. [PMID: 38999084 PMCID: PMC11243737 DOI: 10.3390/molecules29133132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 06/21/2024] [Accepted: 06/27/2024] [Indexed: 07/14/2024] Open
Abstract
Sensitively detecting hazardous and suspected bioaerosols is crucial for safeguarding public health. The potential impact of pollen on identifying bacterial species through fluorescence spectra should not be overlooked. Before the analysis, the spectrum underwent preprocessing steps, including normalization, multivariate scattering correction, and Savitzky-Golay smoothing. Additionally, the spectrum was transformed using difference, standard normal variable, and fast Fourier transform techniques. A random forest algorithm was employed for the classification and identification of 31 different types of samples. The fast Fourier transform improved the classification accuracy of the sample excitation-emission matrix fluorescence spectrum data by 9.2%, resulting in an accuracy of 89.24%. The harmful substances, including Staphylococcus aureus, ricin, beta-bungarotoxin, and Staphylococcal enterotoxin B, were clearly distinguished. The spectral data transformation and classification algorithm effectively eliminated the interference of pollen on other components. Furthermore, a classification and recognition model based on spectral feature transformation was established, demonstrating excellent application potential in detecting hazardous substances and protecting public health. This study provided a solid foundation for the application of rapid detection methods for harmful bioaerosols.
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Affiliation(s)
| | | | | | | | | | | | | | - Zhaoyang Tong
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; (P.Z.); (B.D.); (J.X.); (J.W.); (Z.L.); (B.L.); (F.M.)
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3
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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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4
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Dey S, Sarkar S. Compositional and optical characteristics of aqueous brown carbon and HULIS in the eastern Indo-Gangetic Plain using a coupled EEM PARAFAC, FT-IR and 1H NMR approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:171084. [PMID: 38382603 DOI: 10.1016/j.scitotenv.2024.171084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/30/2024] [Accepted: 02/17/2024] [Indexed: 02/23/2024]
Abstract
This study provides insights into the fluorophoric composition of aqueous brown carbon (BrCaq) and chemically-separated humic-like substances (HULIS): neutral HULIS (HULIS-n; at pH = 7) and acidic HULIS (HULIS-a; at pH = 2) on a seasonal and day-night basis in the eastern Indo-Gangetic Plain (IGP), India. A coupled approach including excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) model, Fourier-transformed infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy was employed to understand the links between structural, compositional and fluorophoric characteristics of BrCaq and HULIS fractions. HULIS fluorophores (HULISfluoro) with varying oxidation states transported from the northwest IGP were dominant during biomass burning seasons (post-monsoon and winter), while protein-like fluorophores (PRLISfluoro) from marine emissions showed large contributions during summer. HULIS-n moieties were mostly primary in nature with higher conjugation, while HULIS-a were associated with secondarily formed and aged species with a larger contribution from degradation products. A substantial presence of tyrosine-like proteins in both chemically-separated HULIS fractions indicated that atmospheric HULIS is not entirely humic or fulvic-like in the eastern IGP. Finally, the dominance of H-C-O groups across seasons suggested consistent fossil fuel signatures along with season-specific influence of photodegradable cellulose from marine organisms in the summer and biomass burning in the post-monsoon and winter.
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Affiliation(s)
- Supriya Dey
- School of Civil and Environmental Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh 175075, India
| | - Sayantan Sarkar
- School of Civil and Environmental Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh 175075, India.
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5
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Rana A, Sarkar S. The role of nitroaromatic compounds (NACs) in constraining BrC absorption in the Indo-Gangetic Plain (IGP). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170523. [PMID: 38296066 DOI: 10.1016/j.scitotenv.2024.170523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/09/2024] [Accepted: 01/26/2024] [Indexed: 02/04/2024]
Abstract
We present here the first measurements of nitroaromatic compounds (NACs) including nitrophenols (NPs), nitrocatechols (NCs) and nitrosalicylic acids (NSAs) from the Indian subcontinent and their role in constraining brown carbon (BrC) absorption. NACs at a rural receptor site in the eastern Indo-Gangetic Plain (IGP) (annual average: 185 ± 94 ng m-3) was dominated by NSAs (135 ± 77 ng m-3), followed by NPs (29 ± 11 ng m-3) and NCs (17 ± 16 ng m-3), with notable enrichments during nighttime and during the biomass burning seasons. An equilibrium absorption partitioning model estimated that >90 % of NSAs and NCs were in the particle-phase, suggesting lower degradation rates via oxidation and photolysis potentially due to year-round high relative humidity. While the contribution of NACs to organic aerosol mass was only 0.42 ± 0.23 %, their contribution to BrC absorption in the 300-450 nm range was higher by an order of magnitude (8 ± 4 %), with NCs and NSAs contributing almost equally in the low-visible (400-450 nm) range as at 365 nm. Despite having mass concentrations lower than NPs by factors of ∼2, contribution of NCs to BrC absorption at λ ≥ 400 nm was comparable to that by NPs, indicating the importance of the absorption efficiency of chromophores. The receptor model positive matrix factorization (PMF) quantified three major NAC sources: fossil fuel combustion (49 ± 15 %; annual average), secondary formation (40 ± 12 %), and biomass burning (11 ± 9 %), with variable contributions on seasonal and day-night bases. In summary, the study uncovered the significant role of NACs in constraining BrC absorption in the IGP, which stresses the importance for molecular-level characterization of BrC chromophores.
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Affiliation(s)
- Archita Rana
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India
| | - Sayantan Sarkar
- School of Civil and Environmental Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh, 175005, India.
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6
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Tang J, Li J, Zhao S, Zhong G, Mo Y, Jiang H, Jiang B, Chen Y, Tang J, Tian C, Zong Z, Hussain Syed J, Song J, Zhang G. Molecular signatures and formation mechanisms of water-soluble chromophores in particulate matter from Karachi in Pakistan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169890. [PMID: 38190909 DOI: 10.1016/j.scitotenv.2024.169890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/30/2023] [Accepted: 01/01/2024] [Indexed: 01/10/2024]
Abstract
Excitation-emission matrix (EEM) fluorescence spectroscopy is a widely-used method for characterizing the chemical components of brown carbon (BrC). However, the molecular basics and formation mechanisms of chromophores, which are decomposed by parallel factor (PARAFAC) analysis, are not yet fully understood. In this study, we characterized the water-soluble organic carbon (WSOC) in aerosols collected from Karachi, Pakistan, using EEM spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We identified three PARAFAC components, including two humic-like components (C1 and C2) and one phenolic-like species (C3). We determined the molecular families associated with each component by performing Spearman correlation analysis between FT-ICR MS peaks and PARAFAC component intensities. We found that the C1 and C2 components were associated with nitrogen-enriched compounds, where C2 with the longest emission wavelength exhibited a higher level of aromaticity, N content, and oxygenation than C1. The C3 associated formulas have fewer nitrogen-containing species, a lower unsaturation degree, and a lower oxidation state. An oxidation pathway was identified as an important process in the formation of C1 and C2 components at the molecular level, particularly for the assigned CHON compounds associated with the gas-phase oxidation process, despite their diverse precursor types. Numerous C2 formulas were found in the "potential BrC" region and overlapped with the BrC-associated formulas. It can be inferred that the compounds that fluoresce C2 contributed considerably to the light absorption of BrC. These findings are essential for future studies utilizing the EEM-PARAFAC method to explore the sources, processes, and compositions of atmospheric BrC.
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Affiliation(s)
- Jiao Tang
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Jun Li
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
| | - Shizhen Zhao
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Guangcai Zhong
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Yangzhi Mo
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Hongxing Jiang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Bin Jiang
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Yingjun Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Jianhui Tang
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
| | - Chongguo Tian
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
| | - Zheng Zong
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Jabir Hussain Syed
- Department of Meteorology, COMSATS University Islamabad (CUI), Islamabad 45550, Pakistan
| | - Jianzhong Song
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
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7
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Devaprasad M, Rastogi N, Satish R, Patel A, Dabhi A, Shivam A, Bhushan R, Meena R. Dual carbon isotope-based brown carbon aerosol characteristics at a high-altitude site in the northeastern Himalayas: Role of biomass burning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169451. [PMID: 38143007 DOI: 10.1016/j.scitotenv.2023.169451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/10/2023] [Accepted: 12/15/2023] [Indexed: 12/26/2023]
Abstract
PM2.5 samples (n = 34) were collected from January to April 2017 over Shillong (25.7°N, 91.9°E; 1064 m amsl), a high-altitude site situated in the northeastern Himalaya. The main aim was to understand the sources, characteristics, and optical properties of local vs long-range transported carbonaceous aerosols (CA) using chemical species and dual carbon isotopes (13C and 14C). Percentage biomass burning (BB)/biogenic fraction (fbio, calculated from 14C) varied from 67 to 92 % (78 ± 7) and correlated well with primary BB tracers like f60, and K+, suggesting BB as a considerable source. Rain events are shown to reduce the fbio fraction, indicating majority of BB-derived CA are transported. Further, δ13C (-26.6 ± 0.4) variability was very low over Shillong, suggesting it's limitations in source apportionment over the study region, if used alone. Average ratio of absorption coefficient of methanol-soluble BrC (BrCMS) to water-soluble BrC (BrCWS) at 365 nm was 1.8, indicating a significant part of BrC was water-insoluble. A good positive correlation between fbio and mass absorption efficiency of BrCWS and BrCMS at 365 nm with the higher slope for BrCMS suggests BB derived water-insoluble BrC was more absorbing. Relative radiative forcing (RRF, 300 to 2500 nm) of BrCWS and BrCMS with respect to EC were 11 ± 5 % and 23 ± 16 %, respectively. Further, the RRF of BrCMS was up to 60 %, and that of BrCWS was up to 22 % with respect to EC for the samples with fbio ≥ 0.85 (i.e., dominated by BB), reflecting the importance of BB in BrC RRF estimation.
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Affiliation(s)
- M Devaprasad
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India; Indian Institute of Technology, Gandhinagar, Gujarat 382355, India
| | - N Rastogi
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India.
| | - R Satish
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - A Patel
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - A Dabhi
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - A Shivam
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - R Bhushan
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - R Meena
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
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8
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Paraskevopoulou D, Kaskaoutis DG, Grivas G, Bikkina S, Tsagkaraki M, Vrettou IM, Tavernaraki K, Papoutsidaki K, Stavroulas I, Liakakou E, Bougiatioti A, Oikonomou K, Gerasopoulos E, Mihalopoulos N. Brown carbon absorption and radiative effects under intense residential wood burning conditions in Southeastern Europe: New insights into the abundance and absorptivity of methanol-soluble organic aerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 860:160434. [PMID: 36427708 DOI: 10.1016/j.scitotenv.2022.160434] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/04/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Biomass burning is a major source of Brown Carbon (BrC), strongly contributing to radiative forcing. In urban areas of the climate-sensitive Southeastern European region, where strong emissions from residential wood burning (RWB) are reported, radiative impacts of carbonaceous aerosols remain largely unknown. This study examines the absorption properties of water- and methanol-soluble organic carbon (WSOC, MeS_OC) in a city (Ioannina, Greece) heavily impacted by RWB. Measurements were performed during winter (December 2019 - February 2020) and summer (July - August 2019) periods, characterized by RWB and photochemical processing of organic aerosol (OA), respectively. PM2.5 filter extracts were analyzed spectrophotometrically for water- and methanol-soluble BrC (WS_BrC, MeS_BrC) absorption. WSOC concentrations were quantified using TOC analysis, while those of MeS_OC were determined using a newly developed direct quantification protocol, applied for the first time to an extended series of ambient samples. The direct method led to a mean MeS_OC/OC of 0.68 and a more accurate subsequent estimation of absorption efficiencies. The mean winter WS_BrC and MeS_BrC absorptions at 365 nm were 13.9 Mm-1 and 21.9 Mm-1, respectively, suggesting an important fraction of water-insoluble OA. Mean winter WS_BrC and MeS_BrC absorptions were over 10 times those observed in summer. MeS_OC was more absorptive than WSOC in winter (mean mass absorption efficiencies - MAE365: 1.81 vs 1.15 m2 gC-1) and especially in summer (MAE: 1.12 vs 0.27 m2 gC-1) due to photo-dissociation and volatilization of BrC chromophores. The winter radiative forcing (RF) of WS_BrC and MeS_BrC relative to elemental carbon (EC) was estimated at 8.7 % and 16.7 %, respectively, in the 300-2500 nm band. However, those values increased to 48.5 % and 60.2 % at 300-400 nm, indicating that, under intense RWB, BrC forcing becomes comparable to that of soot. The results highlight the consideration of urban BrC emissions in radiative transfer models, as a considerable climate forcing factor.
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Affiliation(s)
- D Paraskevopoulou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece.
| | - D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece.
| | - G Grivas
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - S Bikkina
- CSIR-National Institute of Oceanography, Dona Paula, Goa 403 004, India
| | - M Tsagkaraki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
| | - I M Vrettou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - K Tavernaraki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
| | - K Papoutsidaki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
| | - I Stavroulas
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece; Climate and Atmosphere Research Center, The Cyprus Institute, 2121 Nicosia, Cyprus
| | - E Liakakou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - A Bougiatioti
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - K Oikonomou
- Climate and Atmosphere Research Center, The Cyprus Institute, 2121 Nicosia, Cyprus
| | - E Gerasopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - N Mihalopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
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9
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Sharma B, Jia S, Polana AJ, Ahmed MS, Haque RR, Singh S, Mao J, Sarkar S. Seasonal variations in aerosol acidity and its driving factors in the eastern Indo-Gangetic Plain: A quantitative analysis. CHEMOSPHERE 2022; 305:135490. [PMID: 35760126 DOI: 10.1016/j.chemosphere.2022.135490] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/30/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
This study employs ISORROPIA-II for the evaluation of aerosol acidity and quantification of contributions from chemical species and meteorological parameters to acidity variation in the Indian context. PM2.5 samples collected during summer (April-July 2018), post-monsoon (September-November 2018), and winter (December 2018-January 2019) from a rural receptor location in the eastern Indo-Gangetic Plain (IGP) were analyzed for ionic species, water-soluble organic carbon (WSOC), and organic and elemental carbon (OC, EC) fractions. This was followed by estimation of the in situ aerosol pH and liquid water content (LWC) using the forward mode of ISORROPIA-II, which is less sensitive to measurement uncertainty compared to the reverse mode, for a K+-Ca2+-Mg2+-NH4+-Na+-SO42--NO3--Cl--H2O system. Aerosol pH was moderately acidic (summer: 2.93 ± 0.67; post-monsoon: 2.67 ± 0.23; winter: 3.15 ± 0.34) and was most sensitive to SO42- and total ammonium (TNH3) variation. The LWC of aerosol showed an increasing trend from summer (16.6 ± 13.6 μg m-3) through winter (32.9 ± 10.4 μg m-3). With summer as the baseline, the largest changes in aerosol pH during the other seasons was driven by SO42- (ΔpH: -0.70 to -0.82 units), followed by TNH3 (ΔpH: +0.25 to +0.38 units) with K+ and temperature being significant only during winter (ΔpH: +0.51 and + 0.46 units, respectively). The prevalent acidity regime provided three major insights: i) positive summertime Cl- depletion (49 ± 20%) as a consequence of SO42- substitution increased aerosol pH by 0.03 ± 0.20 units and decreased LWC by 2.4 ± 5.9 μg m-3; ii) the rate of strong acidity (H+str) neutralization and the [H+str]/[SO42-] molar ratio suggested the existence of bounded acidity in ammonium-rich (winter) conditions; and iii) significant correlations between LWC, WSOC, and secondary organics during post-monsoon and winter pointed towards a possible indirect role of WSOC in enhancing LWC of aerosol, thereby increasing pH. Given the inability of proxies such as H+str and charge ratios to accurately represent aerosol pH as demonstrated here, this study emphasizes the need for rigorous thermodynamic model-based evaluation of aerosol acidity in the Indian scenario.
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Affiliation(s)
- Bijay Sharma
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India; School of Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh, 175075, India
| | - Shiguo Jia
- Guangdong Provincial Field Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, Guangzhou, 510275, PR China; School of Atmospheric Sciences, Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519082, PR China
| | - Anurag J Polana
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Md Sahbaz Ahmed
- Department of Environmental Science, Tezpur University, Tezpur, Assam, 784028, India
| | - Raza Rafiqul Haque
- Department of Environmental Science, Tezpur University, Tezpur, Assam, 784028, India
| | - Shruti Singh
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Jingying Mao
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 510632, PR China
| | - Sayantan Sarkar
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India; School of Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh, 175075, India.
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