## 1 Introduction  
The increasing generation of complex and highly loaded wastewater, driven by rapid industrialization and population growth, poses a significant environmental challenge. Inadequate treatment and uncontrolled discharge of such wastewater contribute to the deterioration of the water quality of natural water systems and affect the global scarcity of clean water resources [1]. Therefore, there is a need to develop and optimize efficient, sustainable, and cost-effective treatment technologies aligned with the principles of circular water use and environmental protection [2, 3]. Among the various technologies investigated, electrocoagulation (EC) has attracted attention as a promising electrochemical technique for wastewater treatment due to its simplicity of operation, short reaction time, low amount of sludge production, and efficient and wide range of pollutant removal [4, 5, 6, 7]. In EC, metal coagulants are generated in situ by the anodic dissolution of sacrificial electrodes(typically iron or aluminum), forming hydroxide flocs and polymeric complexes that destabilize colloidal and dissolved contaminants, facilitating their removal via sedimentation or flotation [8; 9; 10]. However, standalone EC processes can face limitations such as electrode passivation, high energy consumption, and incomplete removal of certain dissolved species [11]. To address these challenges, hybrid approaches combining EC with sorptive or functional materials have been increasingly investigated [12; 13; 14]. One such approach incorporates natural zeolite (ECZ), which acts as an ion exchanger and adsorbent, improves pollutant capture, reduces electrode fouling through mechanical abrasion, and allows zeolite regeneration and reuse [15; 16; 17]. Another enhancement strategy involves the application of a magnetic field during EC. Magnetic fields introduce magnetohydrodynamic (MHD) effects, which modify ion transport pathways, reduce the thickness of the diffusion layer, and can enhance electrochemical reaction kinetics [18; 19]. Several studies have reported improved turbidity and suspended solids removal when magnetic fields were applied [20; 21; 22]. Beyond that, the application of magnetic fields in water and wastewater treatment has shown broader potential benefits, including reduced formation of scale [23; 24; 25], as well as changes in the physico-chemical properties of water (i.e., surface tension and conductivity) [26]. Moreover, magnetized water has been reported to positively affect microbial activity and biological growth, suggesting possible applications in bio-based treatment systems [27; 28]. In a previous study [29], a novel configuration combining EC, zeolite, and magnetic field assistance (ECZ-MAG) was investigated using carbon steel (Fe) electrodes for the treatment of compost leachate. While chemical oxygen demand (COD) reduction up to 91% was achieved, the magnetic field did not significantly enhance pollutant removal compared to ECZ alone and was associated with increased electrode fouling after extended treatment times. In light of these findings, the present study explores using aluminum (Al) electrodes in a similarly configured ECZ-MAG system to evaluate whether different electrode materials can mitigate fouling, improve energy efficiency, and enhance treatment performance. Compost-derived wastewater was again used as a model of high-strength wastewater, this time with a significantly higher initial organic load (high COD concentrations). The study aims to provide deeper insight into the interplay between the electrode material and magnetic field application in hybrid EC systems. The novelty of this work lies in the systematic evaluation of magnetically assisted EC with zeolite (ECZ-MAG) using aluminum electrodes for the treatment of highly loaded compost-derived wastewater. This area has not been previously explored.