# Parametric Analysis for 3D Modeling of Consolidation-Induced Solute Transport Using OpenFOAM
## 4 Results and Discussion
### Effect of the Partitioning Coefficient on Solute Transport  
To investigate the influence of the linear partitioning coefficient (\(K_{d}\)) on solute transport behavior, a sensitivity analysis was conducted, comparing three representative cases. **Case 1** serves as a reference scenario where no adsorption occurs, allowing solute to migrate unhindered. In contrast, **Case 10** introduces a small \(K_{d}\), signifying weak adsorption and moderate retardation of solute migration. Finally, **Case 11** highlights the impact of strong adsorption, with a large \(K_{d}\) significantly hindering solute transport. Figure 31 illustrates the impact of varying partition coefficients on the behaviour of solute transport over time at two distinct locations: the centre and the edge. At the center, where solute migration is more concentrated, clear differences in transport rates are observed between the three cases. For **Case 1**, with no partitioning effect, the concentration at the top layer (Figure 31a) reaches approximately 0.8 within 20 years. By comparison, **Case 10** shows a reduced concentration of about 0.5, while **Case 11** exhibits a significantly lower concentration of around 0.18. This trend demonstrates how increasing \(K_{d}\) values correspond to greater retardation effects, with higher partition coefficients dramatically slowing solute mobility. At the edge (Figure 31b), where advection is weaker, and flow pathlines are more dispersed, concentration growth is slower across all cases. For **Case 1**, the concentration at the top layer reaches approximately 0.15 within 20 years, while **Case 10** reduces this value to around 0.06 and **Case 11** to just 0.03. The sharper decline in concentrations at the edge is due to the combined effects of diffusion and retardation, particularly in areas farther from the solute source. This highlights the interplay between transport processes in different regions. Vertical concentration variations are explored further in Figure 32. In the center, the differences between the top and bottom layers are pronounced: in **Case 1**, this difference is approximately 0.5 after 20 years, while for **Case 10** and **Case 11**, it reduces to 0.45 and 0.3, respectively. At the edge, the differences are significantly smaller, remaining below 0.1 for all cases. These observations highlight the dominant role of adsorption in slowing the migration of the solute into deeper layers and reducing vertical transport. The partition coefficient has a significant impact on the horizontal variation of the solute concentration (Figure 33). Spatially, the concentration in the center region changes gradually, indicating relatively sufficient solute migration, while in the peripheral region, the concentration decreases rapidly, suggesting limited diffusion effects and migration hindrance at the edges. In **Case 1**, where there is no partition effect, the concentration remains the highest, indicating the fastest solute migration and the ease of reaching higher concentrations. **Case 10** exhibits moderate concentration levels, suggesting that weak partition effects slow the solute migration rate to some extent. In contrast, **Case 11** shows  
Figure 30: Concentration contour plots in the \(x\)-\(y\) plane at \(z=1.5\) m under varying Poisson ratios over 10 years. the lowest concentration with the slowest increase, indicating that strong partition effects significantly hinder solute migration speed. Figure 34 illustrates that \(K_{d}\) has a significant impact on the concentration distribution. Under non-adsorption conditions (**Case 1**), solute accumulation is the strongest, resulting in the highest center concentration. As adsorption becomes stronger (**Cases 10 and 11**), the accumulation of solute in the centre region gradually decreases. This indicates that adsorption significantly influences the spatial distribution characteristics of solutes by controlling their retention capacity within the soil.