Impact of High-Intensity Static Magnetic Field on Chemical Properties and Anaerobic Digestion of Sewage Sludge

Abstract The increasing production of sewage sludge at global level has addressed the search for technical solutions to take advantage from it, reducing environmental burden originating its disposal. Anaerobic digestion is a suitable option handle in accordance with circular economy principles, as it generates methane-rich biogas and digestate potential fertilizing properties. Several techniques have been proposed enhance anaerobic performances and, among these, application static magnetic field (SMF) recently gained attention. Nonetheless, effects high-intensity SMF on destined impact process not evaluated yet. This study aims determine 1.5 T chemical composition well methane generation during digestion. main parameters influencing (i.e., flow rate, mixing ratio magnetized non-magnetized sludge, number pumping cycles, total solid content) were varied evaluate different exposure conditions characteristics sludge. An extensive applied resulted 24% decrease production, reduced concentration monitored ionic species NH 4 + , NO 3 ? PO 3? SO 2? Mg 2+ ) liquid phase promoted precipitation compounds valuable properties, e.g., struvite. These outcomes suggest that SMF, although negatively generation, can promote precipitation, possibly recovery/recycle enhancing proper management perspective. Graphical abstract