Optical and molecular indices of dissolved organic matter for estimating biodegradability and resulting carbon dioxide production in inland waters: A review.

Autor: Begum MS; Department of Environment and Energy, Sejong University, Seoul 05006, South Korea., Park JH; Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea., Yang L; College of Environment and Safety Engineering, Fuzhou University, Fuzhou, Fujian, China., Shin KH; Department of Marine Science and Convergence Engineering, Hanyang University, Ansan, Gyeonggi do 15588, South Korea., Hur J; Department of Environment and Energy, Sejong University, Seoul 05006, South Korea. Electronic address: jinhur@sejong.ac.kr.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2023 Jan 01; Vol. 228 (Pt A), pp. 119362. Date of Electronic Publication: 2022 Nov 14.
DOI: 10.1016/j.watres.2022.119362
Abstrakt: Biodegradable dissolved organic carbon (BDOC) constitutes the most labile fraction of dissolved organic matter (DOM), which also functions as a source of CO 2 emissions from inland waters. However, no systematic review is available on DOM indicators of BDOC and CO 2 production potential. Optical and molecular indices can be used to track small changes in DOM composition during biodegradation. In this review, we identified four different methods for measuring BDOC together with their strengths and limitations. In addition, we discuss the potential of using documented optical indices based on absorption and fluorescence spectroscopy and molecular indices based on Fourier transform ion cyclotron mass spectrometry as proxies for estimating BDOC and biodegradation-induced CO 2 production based on previously reported relationships in the literature. Many absorbance- and fluorescence-based indices showed inconsistent relationships with BDOC depending on watershed characteristics, hydrology, and anthropogenic impacts. Nevertheless, several indices, including specific UV absorbance at 254 nm (SUVA 254 ), humification index (HIX), and terrestrial humic-like fluorescent DOM (FDOM) components, tended to have negative relationships with BDOC in tropical and temperate watersheds under baseflow or drought periods. Protein-like FDOM exhibited the strongest correlation with BDOC in different systems, except during storms and flood events. Despite the limited number of studies, DOM molecular indices exhibited consistent relationships with BDOC, suggesting that the relative abundance of aliphatic formulas and the molecular lability index could act as reliable proxies. The DOM optical indices explain up to 96% and 78% variability in BDOC and CO 2 , respectively; nonetheless, there were limited studies on molecular indices, which explain up to 74% variability in BDOC. Based on literature survey, we recommend several sensitive indices such as SUVA 254 , HIX, and terrestrial humic- and protein-like FDOM, which could be useful indicators of BDOC and dissolved CO 2 in inland water. Future research should incorporate a wider range of geographic regions with various land use, hydrology, and anthropogenic disturbances to develop system- or condition-specific DOM optical or molecular proxies for better prediction of BDOC and CO 2 emissions.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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