Electromagnetic fields for scaling mitigation in water treatment: Mechanisms, challenges, and optimization strategies

Mineral scaling remains a persistent challenge in water treatment systems. Electromagnetic field (EMF) treatment provides a modular and chemical-free alternative to traditional antiscalants, with minimal environmental impact. EMF systems reduce common scales (e.g., CaCO₃, gypsum, silica), but performance is application-dependent, such as ∼15–79 % fouling reduction in bench heat-exchanger/membrane-distillation tests and ∼40–45 % lower scaling propensity in reverse osmosis pilot/field studies. This variability limits large-scale applications. This review synthesizes recent theoretical and experimental advances in EMF-based scale control. EMFs influence both homogeneous nucleation and heterogeneous crystal growth, reducing scale adhesion. The relative contribution of these mechanisms depends on water chemistry and system configuration, leading to varying levels of treatment efficiency. This variability also presents an opportunity: by modulating the balance between homogeneous and heterogeneous effects, EMF systems can be tailored to specific treatment needs, thereby broadening their applicability. The effectiveness of EMF treatment can be further enhanced through optimization of operational parameters such as field intensity, frequency, waveform, and flow velocity. These factors are examined through simulation studies and pilot-scale experiments, offering insights into EMF device design and tuning. The review concludes by identifying key research gaps and proposing integration strategies, such as combining EMF with low-dose antiscalants, to improve cost-effectiveness and scaling control efficiency. By clarifying underlying mechanisms and practical challenges, this review aims to reduce uncertainty and support broader adoption of EMF as a reliable, scalable, and sustainable solution for mineral scaling control.