Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes
<p>Knowledge of the chemical structures and optical properties of water-soluble organic carbon (WSOC) is critical considering its involvement in many key aerosol-associated chemical reactions and its potential impacts on climate radiative forcing. This study investigates the coupled effects of...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-10-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/13845/2022/acp-22-13845-2022.pdf |
| _version_ | 1811335902116446208 |
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| author | Y. Qin J. Qin J. Qin X. Wang K. Xiao T. Qi T. Qi Y. Gao X. Zhou S. Shi J. Li J. Gao Z. Zhang J. Tan Y. Zhang R. Chen |
| author_facet | Y. Qin J. Qin J. Qin X. Wang K. Xiao T. Qi T. Qi Y. Gao X. Zhou S. Shi J. Li J. Gao Z. Zhang J. Tan Y. Zhang R. Chen |
| author_sort | Y. Qin |
| collection | DOAJ |
| description | <p>Knowledge of the chemical structures and optical properties of
water-soluble organic carbon (WSOC) is critical considering its involvement
in many key aerosol-associated chemical reactions and its potential impacts
on climate radiative forcing. This study investigates the coupled effects of
pH and particle size on the chemical structures (functional groups) and
optical properties (UV/fluorescence properties) of WSOC and further
explores the source and aging of WSOC constituents. The results showed that
the specific UV absorbance at a wavelength of 254 nm (SUVA<span class="inline-formula"><sub>254</sub></span>) and mass
absorption efficiency at a wavelength of 365 nm (MAE<span class="inline-formula"><sub>365</sub></span>) were higher in
smaller than larger particles, revealing the relatively higher
aromaticity/molecular weight and more freshness of WSOC in smaller
particles. A decrease in aromaticity/molecular weight of WSOC in larger
particles was caused by the degradation reaction that occurred during the
aging process. The carboxylic groups tend to be enriched in larger
particles, whereas the contribution of phenolic groups was generally higher
in smaller particles. The changes in the fluorescence peak position
suggested that hydroxyl groups play a leading role in pH-responsive
fluorescence in summer, while carboxylic and nitro groups play a dominant
role in winter. Overall, the chromophores in smaller particles showed a more
pronounced pH dependence, which might be related to the higher content of
aromatic species in WSOC in these particle size ranges. Specifically, the
climate impact of WSOC would be enhanced with increasing pH. The pH- and
particle-size-dependent chemical and optical properties of WSOC provide
insights into the structure, source, and aging of WSOC, which will
ultimately improve the accuracy of assessing the climate effects of WSOC.</p> |
| first_indexed | 2024-04-13T17:31:32Z |
| format | Article |
| id | doaj.art-87cec6f91f5f42bf904d0e04153638b7 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-13T17:31:32Z |
| publishDate | 2022-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-87cec6f91f5f42bf904d0e04153638b72022-12-22T02:37:33ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242022-10-0122138451385910.5194/acp-22-13845-2022Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processesY. Qin0J. Qin1J. Qin2X. Wang3K. Xiao4T. Qi5T. Qi6Y. Gao7X. Zhou8S. Shi9J. Li10J. Gao11Z. Zhang12J. Tan13Y. Zhang14R. Chen15College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaGuangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaSchool of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaFaculty of Earth Resources, China University of Geosciences, Wuhan, 430074, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaSchool of Materials and Environmental Engineering, Shenzhen Polytechnic, Shenzhen, 518055, ChinaInstitute of Urban Meteorology, China Meteorological Administration, Beijing, 100089, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, ChinaCollege of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China<p>Knowledge of the chemical structures and optical properties of water-soluble organic carbon (WSOC) is critical considering its involvement in many key aerosol-associated chemical reactions and its potential impacts on climate radiative forcing. This study investigates the coupled effects of pH and particle size on the chemical structures (functional groups) and optical properties (UV/fluorescence properties) of WSOC and further explores the source and aging of WSOC constituents. The results showed that the specific UV absorbance at a wavelength of 254 nm (SUVA<span class="inline-formula"><sub>254</sub></span>) and mass absorption efficiency at a wavelength of 365 nm (MAE<span class="inline-formula"><sub>365</sub></span>) were higher in smaller than larger particles, revealing the relatively higher aromaticity/molecular weight and more freshness of WSOC in smaller particles. A decrease in aromaticity/molecular weight of WSOC in larger particles was caused by the degradation reaction that occurred during the aging process. The carboxylic groups tend to be enriched in larger particles, whereas the contribution of phenolic groups was generally higher in smaller particles. The changes in the fluorescence peak position suggested that hydroxyl groups play a leading role in pH-responsive fluorescence in summer, while carboxylic and nitro groups play a dominant role in winter. Overall, the chromophores in smaller particles showed a more pronounced pH dependence, which might be related to the higher content of aromatic species in WSOC in these particle size ranges. Specifically, the climate impact of WSOC would be enhanced with increasing pH. The pH- and particle-size-dependent chemical and optical properties of WSOC provide insights into the structure, source, and aging of WSOC, which will ultimately improve the accuracy of assessing the climate effects of WSOC.</p>https://acp.copernicus.org/articles/22/13845/2022/acp-22-13845-2022.pdf |
| spellingShingle | Y. Qin J. Qin J. Qin X. Wang K. Xiao T. Qi T. Qi Y. Gao X. Zhou S. Shi J. Li J. Gao Z. Zhang J. Tan Y. Zhang R. Chen Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes Atmospheric Chemistry and Physics |
| title | Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes |
| title_full | Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes |
| title_fullStr | Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes |
| title_full_unstemmed | Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes |
| title_short | Measurement report: Investigation of pH- and particle-size-dependent chemical and optical properties of water-soluble organic carbon: implications for its sources and aging processes |
| title_sort | measurement report investigation of ph and particle size dependent chemical and optical properties of water soluble organic carbon implications for its sources and aging processes |
| url | https://acp.copernicus.org/articles/22/13845/2022/acp-22-13845-2022.pdf |
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