The suitability of the adsorbent was tested by fitting the adsorption data with four isotherms, namely Freundlich,
Langmuir and Temkin. The characteristic parameters for each isotherm have been determined. The Freundlich
equation represented the best fit of experimental data for activated banana peel (ABP) than the other isotherm
equations, and Langmuir equation described the adsorption of natural biosorbent (NBP). It was observed that
activated banana peel was a suitable adsorbent than other for removal of methylene blue from aqueous solutions.
Key words: activation treatment, banana peel, isotherms, cationic dye.