Spectroscopy and Spectral Analysis, Volume. 43, Issue 12, 3937(2023)

Spectroscopic Characterization of Dissolved Organic Matter in Fresh Snow From Harbin

CUI Song, BU Xin-yu, and ZHANG Fu-xiang
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  • [in Chinese]
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    The study of the Spectroscopic characterization of dissolved organic matter (DOM) in fresh snow is conducive to exploring its response to atmospheric pollutants. In this research, ultraviolet-visible absorption spectroscopy (UV-Vis) three-dimensional excitation-emission matrix spectroscopy (3DEEMs) combined with parallel factor analysis (PARAFAC) were applied to analyze the spectral characteristics and sources of DOM in fresh snow samples from Harbin. Chromophoric dissolved organic matter (CDOM) content in fresh snow showed the same trend as the intensity of fluorescent dissolved organic matter (FDOM), CDOM content was different from that in other environmental media due to different DOM sources, atmospheric cloud transport, air pollution and chromophore photobleaching properties, however, the intensity of FDOM was lower than that of soil and ocean owing to the differences in salt content and DOM degradation kinetics. The absorption spectroscopy of DOM in the fresh snow showed an exponentially decreasing trend, similar to the absorption spectroscopy of water-soluble organic chromophores in atmospheric particles in winter. Obviously absorption peaks at 200~220 nm (affected by water molecules and dissolved oxygen) indicated that DOM had more unsaturated double-bond conjugated structures. E2/E3 values (the ratio of absorbance at 250 and 365 nm) indicated that DOM in fresh snow possessed the characteristics of simple structure, small molecular weight and weak aromaticity. Furthermore fulvic-like acid was the main component of DOM in fresh snow. PARAFAC obtained two types of fluorescent components (humic-like and protein-like), and their contributions to fluorescence intensity were 66.78% and 33.22%, respectively. Fluorescence parameters analysis showed that DOM in fresh snow in the present research was affected by both terrestrial input and microbial activity and had strong autogenic characteristics (BIX>1) and weak humification characteristics (HIX<0.8). The correlation analysis between fluorescence components and atmospheric pollutants revealed that the sources of components of fresh snow in Harbin are similar, the sampling time is during the heating period, and the sampling point is near the factory and the railway. Thus fine particulate matter (PM2.5) emitted from fossil fuels, biomass combustion, transportation, and industry were the main sources of DOM in fresh snow. The maximum fluorescence intensity of humic-like components preliminarily established the concentration prediction equation of PM2.5. The analysis of DOM spectral characteristics in fresh snow provided a reference value for revealing its source composition and further exploring its carrier behavior mechanism. Meanwhile, it provided a new research idea and technical support for rapid diagnosis and identification of atmospheric environmental pollution.

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    CUI Song, BU Xin-yu, ZHANG Fu-xiang. Spectroscopic Characterization of Dissolved Organic Matter in Fresh Snow From Harbin[J]. Spectroscopy and Spectral Analysis, 2023, 43(12): 3937

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    Paper Information

    Received: Jun. 30, 2022

    Accepted: --

    Published Online: Jan. 11, 2024

    The Author Email:

    DOI:10.3964/j.issn.1000-0593(2023)12-3937-09

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