Single Calcite Particle Dissolution Kinetics: Revealing the Influence of Mass Transport

Calcite dissolution kinetics at the single particle scale are determined. It is demonstrated that at high under-saturation and in the absence of inhibitors the particulate mineral dissolution rate is controlled by a saturated calcite surface in local equilibrium with dissolved Ca2+ and CO32- coupled with rate determining diffusive transport of the ions away from the surface. Previous work is revisited and inconsistencies arising from the assumption of a surface-controlled reaction are highlighted. The data have implications for ocean modeling of climate change.

Automated summary

The kinetics of calcite dissolution at the single particle scale are determined, showing that the dissolution rate of particulate minerals is controlled by the saturated calcite surface in local equilibrium with dissolved Ca2+ and CO32- ions, and further influenced by the diffusive transport of these ions away from the surface. Previous research assumptions are revisited and inconsistencies due to surface-controlled reactions are emphasized. These findings have implications for simulating climate change in the ocean.