Electroinduced drift of solvated ions in salt solution of Ce and Ni

This paper shows the selective drift of cationic aqua complexes of chloride salts of metal ions in aqueous solutions under the exposure an asymmetric electric field (100 Hz, 750/150 V). The spatial distribution of ${\text{Ce}}^{3+}$ and ${\text{Ni}}^{2+}$ cations was demonstrated, and the maximum cation separation coefficients in the longitudinal section of the inter-electrode space were calculated for the stationary and circulating solution for different exposure durations of the electric field and solution circulation rates. A decrease in the relative concentration of cations was observed when moving from top down of the experimental cell, while the direction of cation drift along the sectional plane was independent of the distance from electrodes, the solution circulation rate, and nature of metal. It was established that while the solution moved from the grounded electrode to the potential electrode along the bottom and top parts of the sections, there was a decrease of concentrations of both cations in the central part of the cell and an increase near the electrodes. On the basis of the obtained data, the optimal points of sampling and drop were determined. The calculated maximum separation coefficients of ${\text{Ce}}^{3+}$ and ${\text{Ni}}^{2+}$ ions were $1.200\pm 0.108$ and $1.036\pm 0.025$, for the stationary and circulating solution at a rate of $7\text{ L}\cdot {\text{h}}^{-1}$, respectively.

Graphical Abstract

SYNOPSIS Drift of ${\text{Ce}}^{3+}$ and ${\text{Ni}}^{2+}$ ions in aqueous solution may be subjected to asymmetric electric field. As a result, the spatial distribution and, consequently, separation coefficients of the cations are determined by the distance from the electrodes, solution circulation rate, metal nature, duration of the electric field exposure, and rates of the solution circulation. .