Reduction of polarization in electrodialysis by ion-conducting spacers

✍ Scribed by Ora Kedem

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 738 KB
• Volume: 16
• Category: Article
• ISSN: 0011-9164
• DOI: 10.1016/s0011-9164(00)84095-3

✦ Synopsis

105-l 1s @ Elsevicr Scientific Publishing Company, Amsterdam -Printed in The Netherlands

REDUCTION OF POLARIZATION IN ELECTRODIRLYSIS BY ION-

CONDUCTING SPACERS

A new method to decrease polarization in electrodialysis is suggested, with the aid of ion-conducting spacers.

Spacers were prepared and tested. It \vas found that high current eficiency can bc preserved at high current densities, in the present esprimcnts up to 30 mA/cm* for a 0.011 N dialysate. Resistance of the dialysate compartment \a5 lower than that corresponding to a homogeneous layer of solution for dilute dialysates. An open stack design made possible by the spacer is discussed.

SY VBOLS

A.1 -Membrane area, cm2 cd -Concentration of dialysate. mo! lit-' i -Current density, amp cm-7, 'II -Useful current ib = -(r,,/~l) jdcjjdr) F JS -Salt flow, mol cm-25ec-' F -Faraday R R:" -Resistance of brine and membranes, R cm2 -Resistance of dialysatc cell, R cm' R* -Total resistance, R cm' 1, -Transport number of cation in the solution V -Voltage across cell Vd -Volume of dialysate, lit t+ -Transport number of cation in the membrane 9 -current efficiency t] = id/i l This work was initiated during leave at the Department of Pharmacology, Biozcntrum, Unitersity of Basel, Su-itzerlsnd.