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Dyes are used in many industrial sectors such as textile, paper, leather and food and cosmetic industries [1] Dyes are known to be toxic and persistent substances in the environment [2] ; They require physico-chemical techniques to degrade them. Adsorption is often used to treat waste water due to the efficient elimination of organic micropollutants and due to economic considerations [3,4].

Methylene blue, MB, is selected as a model organic compound because it is known to adsorb more easily onto solids and in order to evaluate the behavior of sorbent for the removal of organic pollutants from its aqueous solutions. MB has wider applications, which include textile, leather, pulp and paper, temporary hair colorant, dyeing cottons, wools, coating for paper stock and as analytical reagent [5, 6].

In this work, the potential of adsorption of MB from aqueous solution by agricultural waste   peel bean ( EH,) resulting from the water treatment processes was studied. The adsorption characteristics were explored using well-established and effective parameters including the effect of pH, contact time, adsorbent dosage, initial concentration. Experimental sorption isotherms were fitted to the Langmuir and Freundlich isotherm models. The pseudo first, pseudo-second order models were used to study the sorption kinetics.

The elimination ratio obtained with new adsorbents was in the range from 80%. The time necessary to attain the adsorption equilibrium was 120 min. The EH powder can be used as an effective, low cost, and eco-friendly green adsorbent for the removal of  MB from aqueous solution.