The feasibility of an ED (electrodialysis) application to a drinking water softening process has been assessed
using a mathematical model. A one-dimensional analytical model was built to describe the steady state
ionic transport in an ED system by solving the Nernst-Planck equations with the electroneutrality
assumption. The model simulates three ions (one anion and two cations with different charges) through a
diluate boundary layer, cation exchange membrane, and concentration boundary layer. The model study
found that the relatively low ionic concentration required for the effluent of the softening process causes
the ED system to operate near the limiting current density. Near the limiting current density, the ionic
transport is rate-limited at the diluate boundary layer, and it has been shown that the relative calcium flux
can be accelerated by shrinking the diluate boundary layer. The preference of the cation exchange
membrane to divalent ions is proven not to affect the relative calcium flux when the ED softening is
operated near the limiting current density. Includes 7 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1000 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 9 |
| Published : | 11/01/2009 |
