Pre-treated Moroccan natural clays: application to the wastewater treatment of textile industry

The current study was carried out to examine the pre-treated Moroccan natural clays for the removal of methylene blue dye by the adsorption method. The adsorbent was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy. After performing the experiment and analyzing the data, it was found that the optimum conditions for fixing yellow marl and kaolinite (0.05 mm) are 93%–98%. The adsorption kinetics of methylene blue on kaolinite (C = 300 ppm, 50 μm) and on yellow marl (C = 500 ppm, 50 μm) is very efficient. Kaolinite adsorbed better towards basic pH. The equilibrium adsorbed amounts reached 27.5 mg g–1 for yellow marl and 16 mg g–1 for kaolinite. Application of the membranes developed in the treatment of dyes shows that the rejection rates obtained depend on the charge of the ions, their sizes, the charge of the membrane linked to the pH of the filtered solution. The difference in adsorption capacity between the two clays studied is due to the percentage of the clay phase in each and its composition.