This study investigates the potential of Libyan bentonite as an eco-friendly and sustainable adsorbent for the removal of Congo red (CR) dye from aqueous solutions. Natural and acid-activated bentonite samples were collected from the Umm al-Razm region of Libya. Experimental conditions, such as initial CR concentrations (10-60 ppm), pH values (5-10), contact times (5-120 min), temperatures (25°C-55°C), and adsorbent doses (0.001-0.007 g), were applied to natural and acid-activated bentonite samples drawn from Umm al-Razm, Libya, using a batch adsorption approach. Acid activation significantly improved the adsorption performance compared to the natural material. The Freundlich isotherm model describes the adsorption of the CR onto both materials, according to equilibrium data. This conformance highlights the heterogeneous adsorption process involving multilayer formation. Furthermore, thermodynamic analysis definitively proved the process to be endothermic and spontaneous, confirming that increasing the temperature enhances the adsorption capacity. These results offer critical insights into the physicochemical modifications induced by acid activation and illustrate the basic concepts of the mechanism governing CR uptake. The findings offer important insights for developing targeted surface engineering strategies that effectively tackle the inherent electrostatic challenges faced in the design of adsorbent materials.
Aghila et al. (Thu,) studied this question.