The metal adsorption by clays is widely studied. The classical method consists in mixing a volume of
metal solution with a mass of clay and making a series of agitation and centrifugation. The supernatant
is analyzed by an atomic absorption method to determine the concentration adsorbed by clay. But this
method has several disadvantages as the extract may contain impurities which are suspensions that
can yield wrong analysis results. This work aims at studying the influence of a new method that uses
membrane filtration to determine the maximum amount of zinc adsorbed by clay. To prove the effectiveness
of such method, several identification techniques are used. The local clay extracted from Oued
Tfal south west Tunisia, has been characterized. The mineralogical and chemical compositions of the
materials have been determined. Gives the adsorption of Zn(II) studies, experimental data demonstrated
a high regression coefficients with the pseudo-second order kinetics. The equilibrium data showed the
best most suitable model fit to Freundlich and Langmuir models.