Jordan et al. (2026): On the pH-dependent export of anthropogenic alkalinity in pore water through soil: Implications for enhanced rock weathering

Jacob S Jordan, Mohammad Afzal Shadab, Valentina Prigiobbe, Yoshiki Kanzaki, Noah Planavsky and Chris Reinhard,IN: CDRxiv, https://doi.org/10.70212/cdrxiv.2026489.v1

Enhanced rock weathering (ERW) is a highly scalable carbon dioxide removal (CDR) strategy. In ERW deployments, pulverized mineral feedstock is spread on agricultural or managed lands. Upon the dissolution or weathering of the feedstock while exposed to the elements, cations are released, altering the charge balance of the pore water in the soil. The introduction of the divalent cations calcium (Ca²⁺) and magnesium (Mg²⁺) catalyzes the conversion of CO₂ to dissolved inorganic carbon (DIC), principally bicarbonate (HCO₃⁻). The efficacy of ERW hinges on the maintenance and export of HCO₃⁻ through the soil. To explore the mechanistic underpinnings of ERW, the authors develop a theoretical framework for the pH-dependent adsorption and desorption of cation solutes onto charged mineral surfaces in a porous medium.

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