Gildas Fiacre Agossou1, Alphonse Sako Avoceffohoun2, Mamatou Gbankoto3, Vincent Prodjinonto4, and Alassane Youssao Abdou Karim5
1 University of Abomey-Calavi (UAC), Polytechnic School of Abomey-Calavi (EPAC), Laboratory of Applied Chemistry Studies and Research (LERCA), Abomey-Calavi, Benin
2 University of Abomey-Calavi (UAC), Polytechnic School of Abomey-Calavi (EPAC), Laboratory of Applied Chemistry Studies and Research (LERCA), Abomey-Calavi, Benin
3 Non-Communicable Diseases and Cancer Research Unit, Laboratory of Applied Biology Research, Polytechnic School of Abomey-Calavi, University of Abomey-Calavi, Abomey-Calavi, Benin
4 University of Abomey-Calavi (UAC), Polytechnic School of Abomey-Calavi (EPAC), Laboratory of Energy and Applied Materials (LEMA), Abomey-Calavi, Benin
5 Laboratoire d’Etude et de Recherche en Chimie Appliquée- Ecole Polytechnique d’Abomey-Calavi, Université d’Abomey-Calavi, 01 BP 2009 Cotonou, Ben, Benin
Original language: English
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Abstract
The objective of this paper is to propose an adsorption isotherm model for methylene blue on composite activated carbons derived from cotton (Gossypium hirsutum) hulls and capsules. The adsorption mechanism involved was described using a three-parameter model that is intermediate between the Langmuir and Frundlich models and is characterized by its ease of use and physical interpretability. The experimental adsorption data were first adjusted using nine classical isotherm models, whose performance was evaluated using five statistical criteria: the adjusted coefficient of determination, the residual sum of squares, the Akaike information criterion (AIC), and the Bayesian information criterion (BIC). The models were best fitted in the following order: Sips˃ Toth˃ Redlich-Peterson˃ Khan˃Langmuir˃ Frundlich˃ Jovanovich˃ Dubinin-Radushkevich. The proposed model provides the best fit with the experimental data for methylene blue adsorption on activated carbons derived from cottonseed shells and cotton (Gossypium hirsutum) capsules, with a determination coefficient of 0.9910 and a theoretical maximum adsorption capacity qm of 820.86 mg.g-1, approximately double that predicted by classical models, illustrating an expected improvement in the predicted performance of the studied activated carbon.
Author Keywords: modeling, isotherm, adsorption, activated carbon, dye, cotton.
