The Effect of Magnetic Fields on Ion Exchange Processes

The article provides a comprehensive analysis of the influence of magnetic fields on ion exchange processes in water demineralization technologies. It considers the physicochemical mechanisms that determine the behavior of ions in the presence of magnetic fields and their influence on the kinetics, thermodynamics, and efficiency of sorption processes. Particular attention is paid to the role of electromagnetic forces, in particular the Lorentz force, which determines the motion of charged particles in a magnetic field, and the Kelvin force, which manifests itself in inhomogeneous magnetic fields and causes local redistribution of ions in the surface layers of the liquid. It is shown that the individual drift of separate ions under the action of the Lorentz force is practically insignificant due to the predominance of Brownian motion. However, in systems with a large number of ions, the total motion creates local electric currents, whose interaction with an external magnetic field leads to the emergence of volumetric magnetohydrodynamic (MHD) flows. These effects reduce the thickness of the diffusion layer near the surface of ionites, increase the mass transfer coefficient and the intensity of sorption. The Stern–Gui–Chapman model allows describing the influence of magnetic fields on the structure of the double electric layer, reducing the effective potential at the phase boundary and changing the kinetics of ion exchange. In addition to micro-level effects, thermodynamic aspects of magnetic activation are considered. It has been established that the effect of the magnetic field depends on temperature: at temperatures around 25 °C, there is an intensification of the formation of finely dispersed and amorphous sediment structures, which reduces their adhesive capacity and slows down the transition of aragonite to calcite. Thus, taking into account the action of the Lorentz and Kelvin forces and magnetohydrodynamic effects creates a scientific basis for explaining the influence of the magnetic field on ion exchange processes and deepens the understanding of the mechanisms of magnetic activation. A comprehensive analysis of the interaction of magnetic fields with ion motion, the structure of the double electric layer, and local convective flows allows us to more clearly determine how the kinetics of ion exchange change under conditions of magnetic activation. The results show that the magnetic field not only affects individual particles through the Lorentz force, but also stimulates the formation of collective electric microcurrents, which, in turn, enhances mass transfer due to magnetohydrodynamic convection and local Kelvin effects. The integration of theoretical understanding of the influence of Lorentz forces, Kelvin forces, and magnetohydrodynamic effects into the modeling and practical application of ion exchange processes opens up new opportunities for optimizing water treatment technologies and in-depth research into the mechanisms of magnetic activation in physicochemical systems.