Enhancing activated sludge process efficiency using static magnetic fields: Implications for microbial growth and...

The application of static magnetic fields (SMFs) has emerged as a promising, non-chemical strategy to enhance the performance of activated sludge processes (ASPs) in wastewater treatment. This review synthesizes current research on the effects of SMFs on microbial growth, sludge settling, and overall treatment efficiency, providing critical insights into the underlying mechanisms and practical implications. Evidence indicates that SMF intensities below 1 T stimulate microbial proliferation, while higher intensities are generally inhibitory. Optimal enhancement of biological activity and sludge compaction occurs within the 15-50 milli-Tesla (mT) range, particularly in aeration zones and secondary clarifiers. Furthermore, SMFs contribute to improved sludge dewaterability, reduction of bulking episodes, and removal of toxic compounds, all without the need for chemical additives. The review also explores the integration of SMFs with adsorption and advanced oxidation processes (AOPs), highlighting their synergistic roles in pollutant removal. By evaluating Monod kinetic coefficients and biokinetic responses, this work provides a framework for optimizing SMF-assisted ASPs in real-world wastewater treatment facilities. The findings support the use of SMFs as a sustainable and energy-efficient approach for enhancing environmental performance and resource management in wastewater systems.