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Tytuł:
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Effects of C/Mn Ratios on the Sorption and Oxidative Degradation of Small Organic Molecules on Mn-Oxides.
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Autorzy:
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Li H; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina27695, United States.; Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States.
Reinhart B; X-ray Science Division, Argonne National Laboratory, Lemont, Illinois60439, United States.
Moller S; Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware19716, United States.
Herndon E; Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States.
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Źródło:
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Environmental science & technology [Environ Sci Technol] 2023 Jan 10; Vol. 57 (1), pp. 741-750. Date of Electronic Publication: 2022 Dec 19.
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Typ publikacji:
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Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, Non-U.S. Gov't
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Język:
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English
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Imprint Name(s):
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Publication: Washington DC : American Chemical Society
Original Publication: Easton, Pa. : American Chemical Society, c1967-
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MeSH Terms:
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Oxides*/chemistry
Oxides*/metabolism
Manganese Compounds*/chemistry
Oxidation-Reduction ; Minerals ; Citrates ; Oxidative Stress
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Contributed Indexing:
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Keywords: Mn−OC interaction mechanisms; OC immobilization; OC oxidation; OC/Mn molar ratio; phase transformation
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Substance Nomenclature:
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6O7F7IX66E (phthalic acid)
64J2OA7MH3 (manganese oxide)
0 (Oxides)
0 (Manganese Compounds)
0 (Minerals)
0 (Citrates)
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Entry Date(s):
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Date Created: 20221219 Date Completed: 20230111 Latest Revision: 20230115
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Update Code:
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20240104
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DOI:
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10.1021/acs.est.2c03633
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PMID:
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36535081
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Manganese (Mn) oxides have a high surface area and redox potential that facilitate sorption and/or oxidation of organic carbon (OC), but their role in regulating soil C storage is relatively unexplored. Small OC compounds with distinct structures were reacted with Mn(III/IV)-oxides to investigate the effects of OC/Mn molar ratios on Mn-OC interaction mechanisms. Dissolved and solid-phase OC and Mn were measured to quantify the OC sorption to and/or the redox reaction with Mn-oxides. Mineral transformation was evaluated using X-ray diffraction and X-ray absorption spectroscopy. Higher OC/Mn ratios resulted in higher sorption and/or redox transformation; however, interaction mechanisms differed at low or high OC/Mn ratios for some OC. Citrate, pyruvate, ascorbate, and catechol induced Mn-oxide dissolution. The average oxidation state of Mn in the solid phase did not change during the reaction with citrate, suggesting ligand-promoted mineral dissolution, but decreased significantly during reactions with the other compounds, suggesting reductive dissolution mechanisms. Phthalate primarily sorbed on Mn-oxides with no detectable formation of redox products. Mn-OC interactions led primarily to C loss through OC oxidation into inorganic C, except phthalate, which was predominantly immobilized in the solid phase. Together, these results provided detailed fundamental insights into reactions happening at organo-mineral interfaces in soils.