Adsorption of methylene blue and Red195 dyes in aqueous medium by palm bark and sugarcane bagasse: Kinetic and thermodynamic study

In this work,we study the adsorption in aqueous medium of two organic dyes,methylene blue (mb) and red195,on palm bark and sugarcane bagasse. both plant materials have been first characterized. a series of experiments was then conducted to study the influence of different operating conditions on the adsorption capacity. all results obtained show that the cationic dye methylene blue is well adsorbed on the two studied supports than the anionic dye red195 whose adsorption is low. the study of the effect of ph shows that the adsorption of mb dye is affected by too acidic medium. the second-order kinetic model is perfectly applicable in the case of adsorbent/adsorbate systems studied. the adsorption isotherms of mb dye on palm bark and sugarcane bagasse are described satisfactorily by the langmuir model. the palm bark proved to be the most efficient support for removing mb dye. the maximum adsorption capacity of palm bark and sugarcane bagasse is about 111.11 mg/g and 17.54 mg/g,respectively. furthermore,the thermodynamic study of the adsorption of mb dye on the two studied plant materials shows that process is spontaneous,exothermic and physical in nature.