Transport of acetate and chloroacetate weak electrolytes through a thin porous membrane in counter-current electrolysis

Abstract

The transport of weak electrolytes through a porous membrane during counter-current electrolysis has been studied both theoretically and experimentally. The theoretical model is based on the Nernst–Planck equations and the obtained transport equations for the ion constituents are used to solve the fluxes of the ion constituents. Expressions for the diffusion coefficients and transport numbers are also presented. Experiments and calculations for two binary systems (acetic acid in water and monochloroacetic acid in water) and for three ternary systems (acetic acid and sodium acetate in water, monochloroacetic acid and sodium monochloroacetate in water and acetic acid and monochloroacetic acid in water) were performed at a total concentration of 0.01 mol dm–3 or less. The theoretically obtained fluxes of the ion constituents are compared with the experimental fluxes and it is shown that the theoretical model is able to predict the transport phenomena.