Yes you can use linear or non-linear Isotherm models. It all depends on the data set available and you requisite skill with both methodology or approach to isotherms.

I know that the Langmuir equation has a form appropriate for multi-component adsorption. Take two components 1,2 as an example:

n1=nmax*K1*p1/(1+K1*p1+K2*p2)

n2=nmax*K2*p2/(1+K1*p1+K2*p2)

The above are for gas adsorption. For liquid please replace the pressure by the concentration.

And you could search for relevant literatures.

Dear Dounya,what exactly are you asking, I don't understand