Eco-friendly adsorption of Rhodamine B dye using Punica granatum peel from an aqueous medium

This study investigates the development of a low-cost, eco-friendly adsorbent from Punica granatum peel for removing Rhodamine B (RhB) dye from an aqueous medium. The hypothesis was that agricultural waste could be repurposed as an effective adsorbent while minimizing environmental impact. The material was characterized using SEM, FTIR, XRD, TGA, DSC, and pHPZC analysis. Its adsorption performance was evaluated under varying pH, temperature, and ionic strength conditions. The adsorbent achieved a maximum capacity of 44.28 mg/g at neutral pH within 120 min. Adsorption followed the Langmuir isotherm and pseudo-second-order kinetic models, with thermodynamic studies confirming an endothermic and spontaneous process. Regeneration tests identified 1 M citric acid as the most effective eluent, achieving 52.35 % desorption efficiency. The adsorbent preparation cost was $0.00338 /g, reflecting the method's scalability and alignment with green chemistry principles through agricultural waste valorization, minimal energy use, and reduced environmental impact

Exploring Es-sifa clay as a high-performance adsorbent: experimental and density functional theory investigations

The present work explores the effectiveness of Es-sifa clay, located in Morocco, especially in the Draa-Tafilalet region, as an adsorbent. The study focused on methylene blue (MB) as the model contaminant for evaluating adsorption efficiency. The clay was characterized using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, pH at the point of zero charge, and cation exchange capacity measurements. Batch adsorption experiments were conducted under varying conditions, including contact time (5–120 min), stirring speed (100- 400 rpm), initial dye concentration (10–100 mg/L), adsorbent dose (0.25–2.5 g/L), and temperature (25–60 °C), to evaluate and optimize removal efficiency. Results showed that MB removal increased with contact time, adsorbent dose, and agitation speed, but decreased with rising temperature and dye concentration. The adsorption kinetics followed the pseudo-second-order model, and the isotherm data best fit the Langmuir model, with a maximum adsorption capacity of 49.41 mg/g. Thermodynamic parameters confirmed that the process is spontaneous and exothermic. DFT calculations were also performed to provide insight into the adsorption mechanism. MB was found to exhibit a narrow HOMO–LUMO energy gap, low chemical hardness, and high electrophilicity, reflecting strong reactivity and surface affinity. Mulliken charge analysis identified electron-rich heteroatoms and aromatic rings as key interaction sites, with adsorption driven by electrostatic forces, hydrogen bonding, and π-back-donation. These theoretical results are consistent with experimental findings, confirming the strong affinity of MB for Es-sifa clay. This study underscores the potential of Es-sifa clay as a sustainable, low-cost material for eco-friendly wastewater treatment, supporting Morocco’s efforts in waste valorization

Déclaration d'Errachidia et lignes directrices pour le développement durable des écosystèmes oasiens

Les actes de la 1re Rencontre scientifique internationale sur les oasis, ISMO 2023, se sont concentrés sur le thème ''Quel apport de la recherche scientifique pour la sauvegarde et le développement des oasis?'' et ont eu lieu à Errachidia du 20 au 22 novembre 2023. The proceedings of the 1st International Scientific Meeting on Oases, ISMO 2023, focused on the theme ''What contribution does scientific research make to the preservation and development of oases?'' and took place in Errachidia from November 20 to 22, 2023