while plotting the adsorption isotherm for my study i observed both the curve for temkin and freundlich superimposed each other ? the condition was observed for two different adsorbent is such finding is possible. if so why??
These are two different increasing functions: power and logarithmic, but one can choose the values of their parameters so that they have a similar course in a limited range of Ce ("superimposed each other").
I think that is an error in the plot of the two different functions especially when you use the fittings of these functions.
Previously, there was no attached drawing. If you also specify the value of parameters of both isotherms, it will be easy to check if both curves are really superimposed each other.
I think you must check the initial value of both model parameters during Model curve fitting in origin as its more important because mostly people forget to put exact values and then they get graphs as you obtained like superimposed eachother.