## 3 Results
### Quantifying Energy Input and Electrode Loss  
Operational costs encompass all expenses incurred during the procurement of materials used in the process, throughout the treatment and post-treatment phases. Specifically, in the ECZ process, operational costs include the consumption of electrode materials, electrical energy, zeolite, disposal of sludge, and magnetic materials. In the following, only the costs related to electrical energy and electrodes will be considered. Electrode costs were estimated both theoretically using [PERSON]'s law and experimentally by measuring the electrode mass loss before and after hybrid ECZ and ECZ-MAG. Electrode loss (kg/m\({}^{3}\)), Faraday efficiency (%), and Energy input, i.e., the electrical energy requirement (kWh/m\({}^{3}\)), were determined according to Equations (2)-(5). Table 2 summarizes the Electrode loss (kg/m\({}^{3}\)), Faraday efficiency (%), and Energy input, i.e., the electrical energy requirement (kWh/m\({}^{3}\)), for the conducted experiments of hybrid ECZ and ECZ-MAG. These observations correlate with earlier results, where enhanced removal efficiencies for COD and turbidity were found in magnet-assisted processes (ECZ-MAG) at longer durations and moderate mixing speeds. The magnetic field seems to act as a complex modulator, improving pollutant removal and settling performance in certain conditions while sometimes increasing energy input due to altered electrochemical dynamics. This trade-off between improved treatment efficiency and energy input should be carefully considered when optimizing hybrid EC processes for practical application. When comparing the theoretical electrode mass loss calculated via [PERSON]'s law and the actual mass loss measured during the experiments, it was observed that the values derived from [PERSON]'s law were consistently higher; thus, the percentage values of Faraday efficiency (FE) calculated in Table 1 according to Equations (2)-(5) are below 100% (FE in the range 50.89-65.82%). This indicates that the theoretical calculation tends to overestimate electrode consumption. Such discrepancies are often linked to factors like electrode passivation, formation of surface films, or gas evolution, which reduce the effective electrode dissolution during the process. Unlike many studies reporting Faradaic efficiencies (FE%) exceeding 100%--a phenomenon referred to as super-Faradaic efficiency [34; 35; 36]--our results revealed FE% values signifi  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Experiment Mark** & **U\({}_{\textbf{r}}\)** & **C\({}_{\textbf{energy}}\),** & **C\({}_{\textbf{theor}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\  
cantly below this threshold. This can be attributed to the high organic load of the initial compost-derivate wastewater. Elevated concentrations of organic matter may interfere with electrochemical surface reactions, promoting the formation of passivating layers or fouling on the electrode surface. Such effects can hinder electrode dissolution, resulting in an actual mass loss lower than that predicted by [PERSON]'s law. Taguchi-Based Process Optimization: Unraveling Interactions Between Physico-Chemical Process Efficiency, Electrode Dissolution, and Settling Behavior  
The Taguchi method represents an approach that enables investigation of the influence of various parameters on desired characteristics of a process or product. Orthogonal arrays for designing experiments and the signal-to-noise ratio (S/N) for quality evaluation are two key ideas that form the basis of this methodology. Orthogonal arrays represent an arrangement that allows the examination of the influence of several factors simultaneously, without the need to conduct all possible combinations of experimental conditions. An experiment designed in this way reduces the number of required experiments while keeping the results statistically relevant. This research applied an L8 experimental design.