Rieder et al. (2026): Contribution of dissolved organic carbon to total alkalinity in Enhanced Weathering experiments
Lukas Rieder, Mathilde Hagens, Reinaldy Poetra, Alix Vidal, Tullia Calogiuri et al., IN: Applied Geochemistry, https://doi.org/10.1016/j.apgeochem.2026.106685
In this study, the authors tested how dissolved organic carbon (DOC) contributes to non-carbonate alkalinity (ANC) using microcosm experiments with artificial organo-mineral mixtures. They 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.