Adsorption of Methylene Blue on raw and activated Clay: case study of Benguerir clay

The experiments of adsorption of methylene blue (MB) on raw and activated Moroccan clay from Benguerir are reported. It is characterized by X-ray diffraction and Infrared spectroscopy (IR). This clay has been utilized as the adsorbent for the removal of a cationic dye, methylene blue (MB), from aqueous solution by the batch adsorption technique under different conditions such as initial dye concentration, solution pH, temperature, and adsorbent mass. The experimental results showed that adsorption of the dye on the raw and activated clay was pH and temperature dependent. The equilibrium data were well fitted by the Langmuir isotherm. Thermodynamic parameters suggested that the adsorption involved a physical process, spontaneous, and endothermic in nature. The kinetic study showed that the second-order model gives a better description of the kinetics of the adsorption reaction. (author)