Insights into dissolved organics in non-urban areas - Optical properties and sources

Feng Yu; Xiaofei Li; Rui Zhang; Jingning Guo; Wen Yang; Lekhendra Tripathee; Lang Liu; Yuqin Wang; Shichang Kang; Junji Cao

doi:10.1016/j.envpol.2023.121641

Insights into dissolved organics in non-urban areas - Optical properties and sources

Environ Pollut. 2023 Jul 15:329:121641. doi: 10.1016/j.envpol.2023.121641. Epub 2023 Apr 24.

Authors

Feng Yu¹, Xiaofei Li², Rui Zhang¹, Jingning Guo¹, Wen Yang¹, Lekhendra Tripathee³, Lang Liu⁴, Yuqin Wang¹, Shichang Kang⁵, Junji Cao⁶

Affiliations

¹ School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
² School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China; Key Laboratory of Aerosol Chemistry and Physics, State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China. Electronic address: lixiaofei@ieecas.cn.
³ State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
⁴ School of Public Policy and Administration, Northwestern Polytechnical University, Xi'an, 710129, China.
⁵ State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
⁶ Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.

PMID: 37100371
DOI: 10.1016/j.envpol.2023.121641

Abstract

Brown carbon aerosols show obvious light absorption properties in the ultraviolet-visible (UV-Vis) range, which has an important impact on photochemistry and climate. In this study, experimental samples originated from the North slope of the Qinling Mountains (at two remote suburb sites) to study the optical properties of water-soluble brown carbon (WS-BrC) in PM_2.5. The WS-BrC of TY (a sampling site on the edge of Tangyu of Mei county) has a stronger light absorption ability than CH (a rural sampling site, near the Cuihua Mountains scenic spot). The direct radiation effect of WS-BrC relative to elemental carbon (EC) is 6.67 ± 1.36% in TY and 24.13 ± 10.84% in CH in the UV range, respectively. In addition, two humic-like and one protein-like fluorophore components in WS-BrC were identified by fluorescence spectrum and parallel factor (EEMs-PARAFAC). Humification index (HIX), biological index (BIX) and fluorescence index (FI) together showed that the WS-BrC in the two sites may originate from fresh aerosol emissions. Potential source analysis of Positive Matrix Factorization (PMF) model show that the combustion process, vehicle, secondary formation and road dust are the main contributors to WS-BrC.

Keywords: Fluorescence components; Optical properties; Qinling mountains; Source resolution; Water-soluble brown carbon.

MeSH terms

Aerosols / analysis
Air Pollutants* / analysis
Carbon / analysis
Climate
Environmental Monitoring
Particulate Matter / analysis
Seasons
Water / chemistry

Substances

Air Pollutants
Carbon
Aerosols
Water
Particulate Matter