Document Type : Original Research Paper
Authors
1
Laboratory of Materials Sciences, Faculty of Sciences and Technology of Nouakchott, Mauritania, B.P.5026 Nouakchott-Mauritania Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, Materials
2
Laboratory of Materials Sciences, Faculty of Sciences and Technology of Nouakchott, Mauritania, B.P.5026 Nouakchott-Mauritania
3
Unité de Recherche Eau, Pollution et Environnement, Département de Chimie, Faculté des Sciences et Technique, Université de Nouakchott, Nouakchott, Mauritanie
4
Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, Materials for Environment Team, ENSAM, Mohammed V University in Rabat, Morocco
5
Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, Materials for Environment Team, ENSAM, Mohammed V University in Rabat, Morocco.
6
Unité de Recherche Eau, Pollution et Environnement, Département de Chimie, Faculté des Sciences et Technique, Université de Nouakchott, Nouakchott, Mauritanie
10.22059/poll.2025.400874.3083
Abstract
The present research investigated the adsorption of Gold (Au(I)), Copper (Cu(II)) and Zinc (Zn(II)) ions from aqueous solution using a natural clay from Akjoujt region in Mauritania as an low cost adsorbent. The natural Akjoujt clay were characterized by several physical and chemical methods such as X-Ray fluorescence (XRF), X-ray diffraction (XRD), Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), BET surface Area, cation exchange capacity (CEC) and Thermal Gravimetric Analysis (TGA). The removal efficacy of the Akjoujt clay adsorbent for Au (I), Cu(II) and Zn(II ion was studied in batch mode as a function of contact time and temperature. Adsorption kinetics data were modelled using pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetics. The behaviour and the nature of Au (I), Cu (II) and Zn (II) adsorption were analysed by employing the Langmuir, and Freundlich isotherm models. The adsorption kinetics followed the PSO kinetics whereas the adsorption data fitted well with the Langmuir isotherm model. The adsorption capacities (qm) from the Langmuir isotherm for Au(I), Cu(II) and Zn(II) are found as 2.90, 7.93 and 6.45 mg/g respectively. The effectiveness of Akjoujt clay in the adsorption of the three metals from aqueous system was Cu(II) > Zn(II) > Au(I). The thermodynamic calculations suggested the spontaneous nature (ΔG° < 0) of the adsorption process, along with the endothermic characteristics (ΔH° > 0) in all cases. These findings highlight the promising potential of natural clay Akjoujt for efficiently adsorbing Au(I), Cu(II) and Zn(II) from aqueous solutions.
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