Évaluation de l'efficacité d'un charbon actif pour l'adsorption d'un polluant, Optimisation par plan d'expérience de Box-Behnken.

Abstract

This study aimed to evaluate the efficiency of activated carbon (CAP), prepared from date palm stem, in removing Congo red (CR) dye from aqueous solutions. To achieve this, a Box-Behnken design (BBD) was applied to optimize operating conditions and study the effects of three key factors: sorbent dosage (X1), initial dye concentration (X2), and solution pH (X3). The physicochemical properties of the activated carbon showed a zero-charge (pHPZC) value of 10, and Bohm analysis indicated that the activated carbon surface contained a basic group. Kinetic analysis showed that the pseudo-second-order (PSO) model was the most appropriate for describing the adsorption process, with a high correlation coefficient (R2 = 0.99). The equilibrium data were applied to the Langmuir and Freundlich models, with the Langmuir model showing the best fit (R2 > 0.98), indicating monolayer adsorption on a homogeneous

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surface. The maximum adsorption capacity was found to be 142.85 mg/g. Thermodynamic parameters indicated that the adsorption process was endothermic.