Magnetic Field Effects on pH and Electrical Conductivity: Implications for Water and Wastewater Treatment

Abstract

Manipulation of water chemistry plays an important role in water and wastewater treatment. Much effort has been directed at accomplishing such changes in ways that require less energy and material consumption to reduce treatment costs and improve process sustainability. Magnetic fields have been shown to affect the properties of water and its constituents. In this study, theoretical assessments of changes in electrical conductivity and proton concentration, as a function of flow velocity through a magnetic field, were developed and experimentally verified. Experiments were done using a flow-through system consisting of permanent neodymium magnets arranged in a helical pattern in a pipe to generate a constant multidirectional magnetic field (1.350 T). In accordance with increasing flow velocity (8–6 cm/s), the proton concentration decreased from 10⁻⁷ to $6\times 10^{-8}$ mol/L (pH 7–7.22). The model developed in this study indicated that pH would increase from 7 to 14 at a velocity of 100 cm/s. Change of electrical conductivity increased by 100 to 250 μS/cm with increasing flow velocity. The decrease in proton concentration was due to an increase in hydrogen bonding between water molecules and protons. Electrical conductivity was increased due to weakening of the hydration shells around the constituent ions and an increase in the internal electrical field.

Graphical abstract