Ion Exchange Resin Membranes Research Articles

Preferential Ion Transport in Electrodialysis through Ion-exchange Resin Membranes

Abstract Because of the great difficulties encountered when describing preferential ion transport in electrodialytic demineralisation from first principles, an empirical approach is more attractive. Preferential ion transport can be described as a simple separation process with a separation factor which is constant for a certain membrane pair under certain conditions, namely, a constant voltage drop per compartment pair at a constant flow velocity in the compartments, high enough to avoid any serious polarisation. Exceptions occur when one counterion is immobilised to a great extent in the resin, when specific strong binding forces are operative (e. g., ionpair formation), and also when the preferential absorption of a counterion is based on the preferential exclusion of the other counterion. The latter appears to be the case in the separation of Cl− and SO42− at high total electrolyte concentrations. The order and magnitude of preference are, in the first instance, governed by the same factors which govern ion-exchange equilibrium. The separation of ions has been shown to decrease with an increase in the applied electric potential (current density). It has been demonstrated that heterogeneous membranes cause a concentration polarisation at lower current densities than homogeneous membranes and that this early polarisation can be detected from the preferential ion transport data before it can be measured in terms of the resistance of the membrane pack.

Electrodialytic demineralization using permselective membranes—II. An anomaly in the permselectivity of some ion-exchange resin membranes

When a certain type of ion-exchange resin membrane is placed between electrolyte solutions of different concentrations, the permselectivity shows an anomalous relationship with electrolyte concentration. The effect is strong at high mass-transfer rates (electrodialysis), but weak in a system with very low mass-transfer rates (membrane potential). One possible application of the anomaly is proposed.

On the Concentration of Dilute Sodium Sulfite Solution by Using Ion-Exchange Resin Membrane

In order to investigate the suitability of using ion-exchange resin membrane for the recovering of sodium sulfite from the spent liquor of semichemical pulp, we experimentally concentrated dilute sodium sulfite solution by using the ion-exchange resin membrane under various conditions. The apparatus used there had 10 rooms separated with 5 sheets of cation-exchange membrane and 4 sheets of anion-exchange membrane, whose effective area was 9×9 cm. The most effective concentration was carried under the condition of following : 30 volts for the electric pressure between the two electrodes, 22°C for the temperature of the dilute sodium sulfite liquor, 0.7 cm/second for the speed of current of the dilute liquor. Under the best condition, 1% sodium sulfite solution was concentrated to about 20% solution, and the total current efficiency was 85.2%. Any damages of the resin membrane were not observed.

Neutrality Disturbance Phenomenon Observed in the Electrodialysis Using Ion-Exchange Resin Membranes

Neutrality Disturbance Phenomenon Observed in the Electrodialysis Using Ion-Exchange Resin Membranes

On the Transport Number for Ion-exchange Resin Membranes

On the Transport Number for Ion-exchange Resin Membranes

X-Ray Emission Spectrography using Ion Exchange Membranes

THE spot-test technique of X-ray emission Spectrography1 for microgram amounts of elements has been extended to lower concentrations of metal ions by using ion-exchange resin membranes to concentrate the elements present as ions in dilute solution, and to act as a carrier for the sample in the spectrograph.

Ion Exchange Resin Membranes and Resin-Impregnated Filter Paper

MARSHALL1 has prepared zeolite membranes and has used them, as electrodes for the determination of ionic activities in solution in a manner analogous to the use of the glass electrode for the measurement of hydrogen ion activities. It is a logical step to attempt to use ion exchange resins in the form of membranes for similar purposes. However, the difficulties of preparing these are considerable.