1. How nanofiltration membranes work

Initially, nanofiltration membranes were reverse osmosis membranes devoid of electrical charge, manufactured in such a way as to have larger pores than usual, in order to increase permeability (hence the name leaky reverse osmosis).

Both pore size and the charge of ionized or ionizable groups limit the passage of substances under the action of the transfer driving force, due to an essentially hydrostatic pressure gradient (see