## 3 Results
### Kinetic Analysis
Figure 5 shows that the slope of the straight lines (k) is consistently higher when using the BL medium, aligning with the results presented in Section 3.1. The values of k obtained for all metals are displayed in Figure 6, where only the values for the treatments using the BL medium are plotted for simplicity. Previous studies [16] have used correlation coefficients (R\({}^{2}\)) to differentiate which model best fits the experimental data, suggesting that the primary controlling mechanism would correspond to the model with the best mathematical correlation. In the present work, the differences in R\({}^{2}\) are minimal (which could be due to the small number of experimental data used in the mathematical fitting), making it difficult to definitively identify the rate-controlling mechanism. Figure 6 shows that the kinetic constants obtained for the EK treatments are higher than those obtained for the AS ones, for all metals except Zn and Mn (with a very small difference for Mn). These results are consistent with those shown in Figure 4. Additionally, the k values range approximately between 10\({}^{-3}\) and 10\({}^{-2}\) d\({}^{-1}\), whereas [PERSON] [28] reported k values for biologicaling in the range 10\({}^{-4}\)-10\({}^{-3}\) d\({}^{-1}\). It can be suggested that the values obtained in this study are somewhat higher because chemical leaching has been used, which may be faster than biological leaching. Overall, the efficiency and rate of the EK-percolation treatments do not appear to be lower than those of the classical agitated slurry system, suggesting a promising potential for the viability of electrokinetic-assisted percolation. [PERSON] et al. [29] observed similar sphalerite bioleaching rates when comparing shake flasks to percolators; they attributed these similar rates to the comparable available surface area in both systems, indicating that the kinetics of bioleaching were controlled by the solid particle surface area. A similar situation could be considered in the present work. Additional factors should be considered to evaluate the potential advantages of using EK-percolation. Electrokinetics is particularly recommended for water percolation in low-permeability soils, as it facilitates water flow through mineral ores with small particle sizes. This results in a high availability of particle surface area and increased reaction rates. [PERSON] et al. [30] reported limitations in vertical percolation flow by gravity, necessitating the agglomeration of fine-grained ore samples to facilitate percolation. Additionally, water consumption in EK-percolation and the requirements of the BL medium appear to be very low compared to conventional agitated systems. However, pH control in the soil zone near the cathode compartment is crucial to remove leached metals and prevent metal  
Figure 6: Kinetic constant values for the leaching of all metals using BL medium (AS: agitated slurry; EKP: EK-percolation tests). The two proposed models have been considered: (a) Equation (1) and (b) Equation (2). precipitation. Furthermore, the rise in temperature due to ohmic heating when using higher voltage gradients can lead to significant energy losses. Beyond the current analysis, which focuses on the comparative influence of various factors on the rate and efficiency of both systems, future pilot and full-scale studies should consider other factors such as the cost of excavation, transport, soil washing and separation, or electricity consumption.