Transport of Dicarboxylic Acids across Ion-Exchange Membranes

Regularities governing mass transfer of three members of the homologous series of dicarboxylicacids, namely, oxalic, malonic, and succinic acids under the action of concentration gradients and electricalpotential are studied. The integral coefficient of diffusive permeability of oxalic acid across anionite membranesdiminishes with growing solution concentration. This coefficient for cationite membranes is much smaller thanthat for anionite membranes. The permeability of anionite membranes is found to decrease linearly as molarmass increases and the acidity constant of dicarboxylic acids by the first stage decreases. Mass transport acrossionite membranes is studied during electrodialysis of solutions of oxalic acid as a function of its concentrationand the charge passed. Electroosmotic transport of the solvent across ion-exchange membranes is shown to risewith increasing molar mass and decreasing mobility of anions of dicarboxylic acids in the membrane. Coefficients of electroosmotic permeability of solution in the process of electrodialytic transport of the acids are calculated.