The paper presents the results of a detailed study upon the equilibriu
m and kinetics of the Ca2+ and Mg2+ ion exchange on NaX zeolite, in th
e presence of lineary alkylbenzene sodium sulphonate (LABS) and nonylp
henylethoxylate (NF8). The experimental exchange isotherms showed that
under the considered working conditions, the Ca2+ and Mg2+ equilibriu
m is not influenced by the neutral or anionic surfactants presence. In
as far as the exchange rate is concerned, a decrease as compared to t
he witness sample - but a differentiated one - is observed for both ca
tions. The Ca2+ ion exchange rate is diminished mom by the NF8, while
the one of the Mg2+ ion is decreased more by the LABS. The surfactants
presence in the system leads to a slight decrease of the exchange act
ivation energy, this being an argument for the good washing behaviour
of the detergents formulated with zeolites.