Electrocoagulation, Zeolite and Magnetic Assistance for Wastewater Treatment: Assessing the Role of Electrode Material

Efficient wastewater treatment is essential for environmental protection and sustainable water resource management, particularly when dealing with complex wastewater streams. Hybrid processes that combine electrochemical and physicochemical methods are increasingly explored due to their potential to enhance pollutant removal efficiency and reduce operating costs. This study evaluates the performance of hybrid treatment methods for complex compost wastewater by integrating electrocoagulation (EC), zeolite and magnetic assistance using aluminium (Al) and iron (Fe) electrodes. The influence of different electrode materials on magnetically assisted hybrid treatment process was assessed with respect to key treatment indicators, including chemical oxygen demand (COD) and turbidity reduction, as well as electrode mass loss, surface morphology, suspension settling, and EC sludge amount. Energy consumption and electrode usage were also considered to evaluate process economics. The results show that the application of a magnetic field in Al electrode systems slightly improves COD and turbidity removal, enhances anodic dissolution, and contributes to a more homogeneous surface morphology. In contrast, Fe electrodes exhibit a partially opposite response – the magnetic field accelerates floc settling and increases EC sludge production but reduces pollutant removal efficiency due to decreased dissolution intensity. Ferromagnetic Fe electrodes respond more strongly to the magnetic field, promoting aggregation and compaction of Fe-hydroxide flocs and partial surface stabilisation, which leads to lower anode mass loss. Weakly paramagnetic Al electrodes, on the other hand, are not directly affected by the magnetic field, but experience an indirect influence through magnetohydrodynamic (MHD)-induced micro-mixing and improved mass transfer. This leads to more uniform and intensive dissolution and a slightly higher pollutant removal efficiency. These findings provide a deeper understanding of the interactions between electrochemical and magnetic effects in hybrid electrocoagulation and offer guidance for optimising electrode material selection and magnetic field parameters to achieve more efficient and sustainable treatment of complex wastewater.