6. Membranes

6.1 Membrane separation categories

The usual types of membrane separation can be classified according to two criteria on which the transfer mechanism is based:

• the type of membrane permeability and, particularly in the case of water-permeable membranes, its separating capacity (see also , figure 1 ), also known as the cut-off point;

• the nature of the driving force.

Based on these parameters, the various processes theoretically applicable to industrial water treatment [18] can be classified as shown...