Résumé
Research on dye removal from wastewater using adsorbents is increasing. However, the development of suitable adsorbents and the assessment of their adsorbing capacities are still insufficient. Here, Citric Acid-modified Clay (CAC), a promising adsorbent, was prepared for removing the Rhodamine B (RhB) dye. Many techniques (X-ray diffraction, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller method, scanning electron microscopy, and thermogravimetric analyses) were employed to characterize the as-prepared adsorbent. The Brunauer-Emmett-Teller analysis showed that the surface area increased from 89 m2 g-1 in purified clay to 114.50 m2 g-1 in CAC. The effects of several operating parameters, including pH, temperature, adsorbent amount, contact time, and initial RhB concentration, were evaluated. Linear fitting favored Langmuir, while non-linear analysis indicated Freundlich, evidencing heterogeneous adsorption. The kinetic analysis demonstrated that the pseudo-second-order model best described RhB adsorption onto CAC. The thermodynamic parameters showed that RhB adsorption onto CAC was endothermic and spontaneous. These findings indicated that CAC is an efficient adsorbent for removing cationic dyes and could play a potential role in wastewater treatment by adsorption.