Évaluation des performances d’une smectite pour la dépollution des effluents industriels par l’adsorption conjointe de deux colorants textiles

Abstract

A study was conducted on the simultaneous adsorption of the cationic dyes methylene Blue (MB) and rhodamine B (RhB) onto the fine fraction of a natural clay. Chemical analysis and X-ray diffraction revealed that this fraction is primarily composed of beidellite. Examination of the adsorption of MB and RhB under different experimental conditions (contact time, pH, sorbent mass, and initial dye concentration) showed that: (1) the adsorption kinetics for both dyes are rapid and follow a pseudo-second-order model, (2) pH strongly influences adsorption efficiency, with maximum uptake under acidic conditions, and (3) the adsorption capacities, estimated using the Langmuir model, reached about 0.70 mmol g⁻¹ for MB and 0.12 mmol g⁻¹ for RhB, confirming the higher affinity of the clay for MB.