Journal of Applied Electrochemistry

, Volume 13, Issue 4, pp 473–487

Water desalting by means of electrochemical parametric pumping

I. The equilibrium properties of a batch unit cell

Authors

  • Y. Oren
    • Nuclear Research Center
  • A. Soffer
    • Nuclear Research Center
Papers

DOI: 10.1007/BF00617522

Cite this article as:
Oren, Y. & Soffer, A. J Appl Electrochem (1983) 13: 473. doi:10.1007/BF00617522

Abstract

It was shown previously that adsorption of ions at the electrical double layer of a high specific surface area carbon electrode can serve for water desalination. This is effected by assembling two such electrodes in a cell, cycling electronic charge between them and applying periodic synchronous pumping of the liquid through the cell. This process has been termed Electrochemical Parametric Pumping (ECPP). In the present article, modified charge coordinates, desalting efficiencies, isopotentiograms (analogous to adsorption isotherms) and optimization considerations of the two adsorptive electrode batch unit of the ECPP were derived and analysed on the basis of the propterties of each single electrode separately.

Nomenclature

a0,a0+,a,a+

ionic activities at the inlet and outlet solutions.

c1,c2

specific double layer capacities of electrodes 1 and 2 (μF g−1)

Ce

specific cell capacitance (μF g−1)

C

solution concentration (mol cm−3)

E1,E2

potential of electrodes 1 and 2 versus a reference electrode

ΔE

potential difference between the two electrodes (V)

E0

potential attained by the electrodes after short-circuiting

F

Faraday constant

g1,g2

weights of electrodes 1 and 2 (g)

i

denotes electrode 1 or 2 in a two electrode system

K

dielectric constant of the solution at the double layer region

ΔnS

change in salt content in the solution in one electrode system (moles)

Δn+, Δn

total amount of adsorbed cations and anions in one electrode system (moles)

nst

total amount of salt adsorbed on the electrodes (moles)

ns

amount of salt adsorbed per unit weight of electrode material (moles g−1)

ni,ni+

amount of anions and cations adsorbed on unit weight of electrodei (wherei=1, 2) (mol g−1)

Δq

the change in total electrode charge in one electrode system (C)

qi

total charge per unit weight of electrodei (C g−1)

qi+,qi

cationic and anionic charges per unit weight of electrodei (C g−1)

qe,qd

independent charge coordinates (C g−1)

R

gas constant

T

absolute temperature

w

electrical work of charging the double layer (eV)

ε0

free space permittivity

μ1,μ2

relative weights or elelctrode 1 and 2 respectively

Download to read the full article text

Copyright information

© Chapman and Hall Ltd 1983