Contribution of dissolved organic carbon to total alkalinity in Enhanced Weathering experiments
Rattachement africain : de, nl, se, in, be. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Total Alkalinity (TA) is widely used as a proxy for captured CO 2 in enhanced weathering (EW) applications. However, organic anions can also contribute to TA. To improve carbon accounting in EW, which is often simplified to that TA equals carbonate alkalinity, their contribution should be taken into account. In this study, we tested how dissolved organic carbon (DOC) contributes to non-carbonate alkalinity (A NC ) using microcosm experiments with artificial organo-mineral mixtures. We used different combinations of rock powder with straw, microbes and earthworm additions, under ambient air conditions. The microcosms were flow-through columns placed in a climate chamber at 25 °C, which were irrigated with groundwater at rates between 1200 and 3600 mm/yr. The concentrations of several low-molecular-weight organic acids (oxalate, citrate, acetate, gluconate) were quantified to assess which conjugate base anions impact the measured TA. Results revealed a ratio of 3.5 mol DOC per A NC equivalent. In the overall experiment the median contribution of A NC to TA was around 5.5 %. A positive correlation between DOC and charge-balance error suggests that some organic acid anions remained deprotonated during TA titration. Acetate anions found in DOC-rich water samples further support a substantial contribution of organic anions to TA. To investigate the relevance of A NC for natural EW systems, we also quantified A NC contributions in natural waters and leachates from soil EW experiment mesocosms. Because DOC levels were lower, A NC contributions were smaller, ranging from a median of 4.1 % in soil mesocosm leachates down to 0.9 % in Elbe estuary water samples. This A NC contribution, despite seeming small, is relevant for carbon accounting in terrestrial EW practices, where TA is often assumed to be solely carbonate alkalinity.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Contribution of dissolved organic carbon to total alkalinity in Enhanced Weathering experiments
- Date Crossref
- 01/02/2026
- Éditeur
- Elsevier BV
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Universität Hamburg pays non établi dans la noticeUniversité ou école supérieure
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Wageningen University & Research Soil Chemistry Group pays non établi dans la noticeUniversité ou école supérieure
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Uppsala University Department of Earth Sciences pays non établi dans la noticeUniversité ou école supérieure
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Swedish University of Agricultural Sciences Department of Molecular Sciences pays non établi dans la noticeUniversité ou école supérieure
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Ganpat University pays non établi dans la noticeUniversité ou école supérieure
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Province of Antwerp pays non établi dans la noticeOrganisme public
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University of Antwerp Biobased Sustainability Engineering (SUSTAIN) pays non établi dans la noticeUniversité ou école supérieure
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University of Hamburg Department of Earth System Sciences pays non établi dans la noticeUniversité ou école supérieure
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Faculty of Agriculture pays non établi dans la noticeUniversité ou école supérieure
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Carbon Drawdown Initiative Carbdown GmbH pays non établi dans la noticeEntreprise
Universität Hamburg, Soil Chemistry Group — Wageningen University & Research et Department of Earth Sciences — Uppsala University, avec 7 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.