A study of ionic transfer in electrodialysis process with laminar flow

Abstract

The concentration profile in a laminar flow of the diluent of a parallel-plate electrodialysis stack is derived by assuming operation at the limiting current density. The Nusselt mass transfer number is found to depend on the Reynolds number, the Schmidt number and the dimensionless hydraulic equivalent diameter according to = 3.7 . (Re . Sc . de/L)'/3. An empirical correlation of the Reynolds number, the Schmidt number, and the shape factor of the electrodialysis cell, with the ionic mass transfer rate in ion exchange membrane electrodialysis is obtained by measuring the limitin current densities at various conditions. The resulting empirical mass-transfer correlation,

Selective transport of metal ions through cation exchange membrane in the presence of a complexing agent

“…The membrane diffusion coefficient was obtained from the Blaedel-Haupert-Evenson equation (Blaedel et al, 1969;Kojima et al, 1982). On the basis of the Yamabe-Seno equation, the stagnant liquid film thickness was estimated from the limiting current method (Huang and Wang, 1989).…”

Preferential Transport of Cupric and Ferric Ions Through Ion Exchange Membranes With Electrodialysis in the Presence of Citric Acid

“…The diffusion coefficients of metal ions in the membrane, Dj , have been measured experimentally in an earlier paper (Huang and Lin, 1989). Based on the Yam abe and Seno equation, the stagnant diffusion film thickness, 8, was estimated by measuring the values of the steady state current for different effective applied voltages (Huang and Wang, 1989) and plotting I-V curves shown in Figure 1. These parameters used in numerical calculation were tabulated in Table I. In general, a permselectivity coefficient, T~, used to describing the competitive transport behavior between ion A and ion B, can be defined as (11) The permselectivity coefficient can be also determined experimentally from the following equation T~= In(~.o/C~.,)/ln(C~.o/C~./)…”