The objective of this work is the valorization of a waste of vegetable origin of the food industry (olive industry) for the obtaining of a Bio-adsorbent which will be used for the elimination of a cationic dye, in this case the Green of Malachite, by a physicochemical process which is the Adsorption.The point of zero charge (pHPZC) of our Powdered Activated Carbon used in this study was determined by the drift equilibrium method and its value was 8.03. The study of the influence of factors, such as initial dye concentration, mass of the support, temperature, agitation and ionic strength for cation salts, indicated that these elements affected the kinetics and adsorption capacity. The adsorption process of our dye on the prepared Bio-adsorbent was well described by an apparent kinetics of order 2. Moreover the different results obtained were modeled using Langmuir, Freundlich and Temkin models and the Langmuir model was the most representative. The calculation of the interaction energy variation DeltaQ from the Temkin isotherm allowed to conclude that this variation is endothermic.