1998 Volume 23 Issue 5 Pages 266-272
Our proposal is that over a certain range of the solute concentration of multi-component electrolyte mixtures, it is possible to assume that each ion can transport independently through a membrane without interaction between the ions and between each ion and the membrane charge. In this paper, the results of experiments obtained using a commercial nanofiltration membrane with 8 kinds of underground brackish water are reported; the results are then used to obtain ion permeabilities using transport equations. From these results it is possible to estimate each ion concentration and pH in the permeate. The effect of osmotic pressure can be estimated from the calculated ion concentrations. Finally, it is shown that the mass transfer coefficients obtained can be correlated to the similar equation previously reported for the spiral-wound type module.
Although assumptions made in this paper have a certain limit in application, with this method it is simple to estimate permeate water qualities.
