Amann et al. (2022): Enhanced weathering potentials—the role of in situ CO2 and grain size distribution

Thorben Amann, Jens Hartmann, Roland Hellmann, Elisabete Trindade Pedrosa, Aman Malik IN: Frontiers in Climate, Sec. Negative Emission Technologies,

To elucidate the effects of grain size distribution and soil partial pressure of carbon dioxide (pCO2) levels on CO2 uptake rates, two simple column experiments were designed and filled nearly daily with an amount of water that simulates humid tropical conditions, which prevail in areas known for being hotspots of weathering. Multiple materials (dunite, basanite, agricultural oxisol, a combination of the latter two, and loess) were compared under ambient and 100% CO2 atmosphere. In a second series, single material columns (dunite) were filled with three different grain size distributions. Total alkalinity, pH, major ions, and dissolved silica were determined in the outflow water of the columns for about 300 days.