Applicability and characterization of the natural Moroccan clay for cationic dye removal: Kinetic, isotherms studies, and application on effluent treatment for textile dyeing

Textile industries, among others, constitute significant contributors to the release of large quantities of intensely colored wastewater. The aim of this study was to investigate the adsorption of methylene blue (MB) using Natural Moroccan clay (NMC). The NMC was characterized by, Brunauer-Emmett-Teller (BET), Point of Zero Charge (pHPZC), Fourier-Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) was determined. Adsorption key variables, including dosage of adsorbent dose, solution pH, and initial concentrations, effect of ionic strength, contact time and temperature were inspected for determining their impacts on MB dye removal. The adsorption process of MB onto NMC was examined using various isotherm models, such as Langmuir, Temkin and Freundlich. The results indicate that the adsorption process is characterized by the Langmuir isotherm, which is confirmed by the fitting data and the comparison of the correlation coefficient (R2). This suggests the highest adsorption capacity of 32.14 mg/g. The pseudo-second order kinetic model provides a good fit for the kinetic data, achieving an R2 value of 0.997. From these results, the method is employed for textile wastewater treatment primarily composed of methylene blue. By effectively treating textile wastewater, the natural Moroccan clay offers a sustainable and eco-friendly solution. Furthermore, it can be utilized as an economical alternative to expensive commercial clay.