## 3 Results
### Solid-Liquid Separation Dynamics  
A settling test was performed under varying operational conditions to evaluate the effectiveness of solid-liquid separation following EC processes (Figure 8). For the first set of experiments, the most efficient settling was observed in the ECZ-MAG processes conducted for 10 min at both 250 and 350 rpm, where most of the sludge settled within the first two min. However, due to the high turbidity of the supernatant above the sludge layer, the turbidity removal percentages were negative (as shown in Figure 3). In the second set of experiments (20 min duration), the best settling performance was also achieved after hybrid ECZ-MAG processes at 250 and 350 rpm. For the experiments with a duration of 30 min,the most effective settling occurred in the ECZ process at 350 rpm. The settling curves indicate a positive impact of the magnetic field on the separation performance during the 10 and 20 min experiments, while its presence did not enhance settling efficiency in the 30 min processes. Based on results of the treatment of compost-derived wastewater using magneto-assisted EC (ECZ-MAG) shown in Figure 7, the presence of a magnetic field demonstrated several notable effects on the process performance. While the total mass loss of the anode remained comparable to that in non-magnetic plants (Figure 6)--indicating that the magnetic field does not significantly affect the dissolution of the aluminum anode--it still led to significant changes in sludge sedimentation dynamics. In particular, shorter duration experiments (10 and 20 min) showed evidence of enhanced electrochemical activity in ECZ-MAG assemblies, not necessarily through increased anode dissolution, but likely through enhanced mass transfer and magnetically induced micro-mixing. These effects accelerate the formation and aggregation of Al\({}^{3+}\) species, which are crucial for coagulation, leading to faster flake formation. Moreover, ECZ-MAG processes led to faster sludge formation and settling, particularly evident in the first few minutes of sedimentation, where most of the sludge settled rapidly. This behavior was especially prominent in the 10 min ECZ-MAG treatments at both 250 and 350 rpm, even though the supernatant remained highly turbid--indicating fast agglomeration but incomplete clarification. Overall, the magnetic field positively influenced the EC performance for shorter treatment times, improving both coagulant availability and solid-liquid separation kinetics. However, in 30 min treatments, the magnet did not show significant advantages, possibly due to electrode passivation or the saturation of removal capacity over prolonged operation. In contrast to our previous findings using Fe electrodes [29], where the settling curves demonstrated a clearly defined slope and efficient sludge settling at longer contact times (20 and 30 min), while showing poor settling performance at 10 min in hybrid (magnet-assisted) systems, the present results with Al electrodes exhibit an inverse trend. Here, the magnetic field notably enhanced sludge settling during shorter treatment durations (10-20 min) by promoting particle aggregation and floc formation. However, at 30 min, the settling efficiency in non-magnetic systems slightly surpassed that of magnet-assisted ones, likely due to natural floc stabilization over time. These differences highlight the crucial  
Figure 8: Settling test results after ECZ and ECZ-MAG processes at different mixing speeds (250 and 350 rpm), categorized according to process duration: (**a**) 10 min, (**b**) 20 min, (**c**) 30 min. The parameter h represents the height of the solid–liquid interface. Note: standard deviation from the average h-values is in the range \(\pm\)(0.099–0.270) cm. role of electrode material in determining the system's response to magnetic assistance.