InterPore2026

Pore-Scale Reactive Transport Modeling of Mineral Dissolution with a New Roughness-Based Surface Reactivity Parameterization

21 May 2026, 15:35

1h 30m

Poster Presentation (MS09) Pore-Scale Physics and Modeling Poster

Speaker

Sina Parsa (Eberhard Karls University of Tübingen)

Description

Accurate modeling of mineral dissolution plays a key role in many geochemical processes. Previous studies have demonstrated the need for parameterizing the intrinsic surface reactivity in reactive-transport models (Agrawal et al., 2021). Recent surface nanotopographic parameterization methods are based on the nanoroughness of the surface (Yuan et al., 2021) and the surface slope (Karimzadeh and Fischer, 2021; Schabernack and Fischer, 2022). However, surface-slope calculations are difficult in three-dimensional (3-D) systems because minerals have several faces with different orientations, requiring a separation of surface faces and slope calculations in coordinates aligning with the faces. This limits the applicability to complex geometries containing edges, corners, and arbitrarily oriented surfaces. In this study, we propose a new roughness-based method using the micro-continuum approach (Soulaine, 2024). We suggest a rotation-invariant roughness factor Rq, computed at each surface point from the covariance matrix of coordinates of that point and its neighbors on the surface. The smallest eigenvalue measures the variance normal to the local tangent plane, providing our orientation-independent roughness factor Rq. This metric is then used to parameterize surface reactivity in the pore-scale reactive-transport model for arbitrarily oriented surfaces. We demonstrate the approach in three numerical experiments of calcite dissolution using different geometries with distinct surface orientation: (i) a two-dimensional (2-D) rough channel, (ii) a complex 3-D polycrystalline calcite marble surface, and (iii) a 3-D calcite crystal. The model results show that the calculated Rq consistently identifies highly reactive edges and corners versus weakly reactive flat faces. The resulting heterogeneous dissolution patterns and orientation-independent surface evolution are validated with published experimental data, confirming the general applicability of the proposed methods for modeling mineral dissolution with complex geometry. The proposed parameterization improves the predictability of reactive-transport models at the pore scale, thus contributing to an enhanced prediction of mineral dissolution at the Darcy scale and beyond.