Book - Applets -

The model consists of 30 effective plates.

Each plate corresponds to certain amount of the exchanger. The material in each plate is surrounded by the solution. Two single-charged ions A and B are exchanged.

A batch equilibrium distribution of ions between the exchanger and solution is calculated for each effective plate in each step.

The column performance is represented by a series of discrete actions (shifts or discrete movements of the solution). At the step number n, each effective plate is equilibrated with surrounding solution. A solution shift is considered after the equilibration, i.e., at step number n+1, the solution moves from one plate to the next one along the column. After the shift, equilibria are established again.

Concluding: continuous flow of the solution is modelled as a number of discrete shifts along a number of batch ion exchange reactors (effective plates).

K is the ion exchange constant, see equation (11.1) in the book.

Capacity is the total capacity of one effective plate.

Volume is volume of the solution surrounding one effective plate.

[A] is concentration of the ion A in the feed solution.

[B] is concentration of the ion B in the feed solution.

Graphical representation is:

**Left column** represents the ratio between concentrations of A (red) and
B (blue) ions in the solution located between the exchanger beads.

**Right column** represents the ratio between contents of A (red) and
B (blue) ions in the exchanger.

Each **square** represents one effective plate in the column.

The **square at top-left corner** represents the feed solution composition.

The **square at bottom-left corner** represents the effluent.

One step can be executed pressing the button [+1 step]. Several steps at once can be executed pressing the button [+ steps]. The number of steps to perform can be introduced in the text field above the button. To start a new experiment, change the characteristics and press the button [reset]. The column will be reset to A form equilibrated with solution containing only A.