Dataset Information

Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin.

ABSTRACT: Fly ash-the residuum of coal burning-contains a considerable amount of fossilized particulate organic carbon (FOCash) that remains after high-temperature combustion. Fly ash leaks into natural environments and participates in the contemporary carbon cycle, but its reactivity and flux remained poorly understood. We characterized FOCash in the Chang Jiang (Yangtze River) basin, China, and quantified the riverine FOCash fluxes. Using Raman spectral analysis, ramped pyrolysis oxidation, and chemical oxidation, we found that FOCash is highly recalcitrant and unreactive, whereas shale-derived FOC (FOCrock) was much more labile and easily oxidized. By combining mass balance calculations and other estimates of fly ash input to rivers, we estimated that the flux of FOCash carried by the Chang Jiang was 0.21 to 0.42 Mt C⋅y-1 in 2007 to 2008-an amount equivalent to 37 to 72% of the total riverine FOC export. We attributed such high flux to the combination of increasing coal combustion that enhances FOCash production and the massive construction of dams in the basin that reduces the flux of FOCrock eroded from upstream mountainous areas. Using global ash data, a first-order estimate suggests that FOCash makes up to 16% of the present-day global riverine FOC flux to the oceans. This reflects a substantial impact of anthropogenic activities on the fluxes and burial of fossil organic carbon that has been made less reactive than the rocks from which it was derived.

SUBMITTER: Li GK

PROVIDER: S-EPMC8166106 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature

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Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin.

Li Gen K GK Fischer Woodward W WW Lamb Michael P MP West A Joshua AJ Zhang Ting T Galy Valier V Wang Xingchen Tony XT Li Shilei S Qiu Hongrui H Li Gaojun G Zhao Liang L Chen Jun J Ji Junfeng J

Proceedings of the National Academy of Sciences of the United States of America 20210501 21

Fly ash-the residuum of coal burning-contains a considerable amount of fossilized particulate organic carbon (FOCash) that remains after high-temperature combustion. Fly ash leaks into natural environments and participates in the contemporary carbon cycle, but its reactivity and flux remained poorly understood. We characterized FOCash in the Chang Jiang (Yangtze River) basin, China, and quantified the riverine FOCash fluxes. Using Raman spectral analysis, ramped ...[more]

PMID: 34001595

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Dataset Information

Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin.

Publications

Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin.

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