http://dspace.univ-usto.dz/handle/123456789/30 2026-04-18T09:08:32Z http://dspace.univ-usto.dz/handle/123456789/260 Titre: Caractérisation de la vase de dragage du barrage de l’Oued Fodda et valorisation en tant que matériau de construction Auteur(s): Benasla, Mohamed Résumé: La retenue du barrage de l’Oued Fodda est soumise à une forte Sédimentation en raison des volumes considérables d'apports solides transportés chaque année par les rivières surtout lors des fortes crues. C’est ainsi, qu’un volume de 103.10 6 m 3 de vase s’est déposé réduisant ainsi sa capacité à moins de 45 % [1]. Afin de prolonger la «durée de vie» de cet ouvrage, le dragage de la retenue est devenu une solution indispensable malgré les énormes quantités de vases extraites par les vannes de fond du barrage et qui ne trouvent aucune application et leur stockage pose actuellement un problème qui menace l'environnement. Dans cet article, nous allons faire une étude basée sur des analyses physiques, chimiques et minéralogiques de la vase prélevée dans la retenue du barrage de l’Oued Fodda. Les résultats des analyses obtenus vérifient bien les normes d’une argile utilisée pour la fabrication de céramique. 2015-10-25T00:00:00Z http://dspace.univ-usto.dz/handle/123456789/208 Titre: Desalination and Water Treatment Auteur(s): Azri Yamina, Mounia; Zerouali, Djilali Résumé: In this study, the electrochemical deposition of gold (Au) onto graphite has been performed under different deposition potential conditions. These Au particles electrodeposited on the graphite were used as cathode for O2 electrochemical reduction and H production in acidic solution, and the hydrogen peroxide (H2O) electrogenerated on graphite modified by gold particles was used in electro-Fenton process. Results show firstly that the O2 cathodic reduction on gold particles electrodeposited on the graphite electrode in acidic medium with two well-defined reduction waves at −300 mV/SCE and −1,300 mV/SCE; those waves indicated reduction of two O2 electrons to H2O. Secondly, the optimal cathodic potential condition for H2O 22 generation on cathode modified was −300 mV and unmodified one was −500 mV/SCE. The electrolysis time, dissolved oxygen level, magnetic stirring, and pH were systematically studied; the hydrogen peroxide production increased with the aeration and electrolysis time and then became stationary after 2 h of electrolysis. The maximum Haccumulation increased up to 60 mg/L with air compressed, at −300 mV. Optimized parameters (potential, oxygen level, and concentration of ferrous ions) were also applied to incinerate the Belgard EV2030 sodium salt of polycarboxylic acid. The incineration efficiency onto optimized parameters shows that 74% of Chemical oxygen demand was incinerated in the modified electrode that confirms the positive gold modification effect onto the performance. 2015-05-25T00:00:00Z http://dspace.univ-usto.dz/handle/123456789/207 Titre: Influence of Hydration on the Neutral Complex ( - OH, H 3 O + ) (H 2 O) n Auteur(s): Benyettou, Fatma; S.HIADSI; A.BENDRAOUA Résumé: Density-functional theory (DFT) within local density approximation (LDA) has been carried out for a sequence of hydrated proton clusters. Optimised structures were odtained for n=0, 1 and OH, H3O+)(H2O)n, complex . Hydronium ion H3O+ and hydroxide ion OH are found to be the center of the neutral complex (-OH, H3O+-). The LDA give shorter hydrogen bond lengths O-H, bslightly longer chemical bond lengths O…H as compared with the Post-Hartree-Fock calculations.We found that the distance O...H successively increases with the number of water molecules added to the neutral complex (-OH, H3O). The solvent effects on proton transfer energy barriers in clusters have been studied. The harmonic vibrational frequencies and IR intensities of various modes have been generated for all optimised structures. This study was confirmed by vibrational studies of these complexes, our results give excellent agreement with experimental values. 2015-05-19T00:00:00Z http://dspace.univ-usto.dz/handle/123456789/206 Titre: β-diketone functionalized SBA-15 and SBA-16 for rapid liquid–solid extraction of copper Auteur(s): R. Ouargli; R. Hamacha; N. Benharrats; A. Boos; A. Bengueddach Résumé: b-diketone functionalized SBA mesoporous materials were used successfully for the removal of copper from aqueous solution. SBA-15 and SBA-16 were impregnated with an acid ligand, 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone (HPMSP) via the wet impregnation method. Characterization techniques showed that the highly ordered structure of the functionalized SBA is well retained after impregnation by the HPMSP. The effect of different extraction parameters, such as equilibrium time, extraction rate as a function of pH, nature of the medium (presence of NO 3- or SO4 2-) and the extraction capacity has been studied and discussed. A copper uptake close to 99.99 % for functionalized SBA-15 and SBA-16 was achieved within only 5 min at lower pH values, thus the extraction kinetics are very rapid and instantaneous as attested by the immediate green coloration of the materials when mixed with copper solution. The extraction capacities of copper were determined about 22 and 25 mg/g at pH 3 respectively for SBA-15 CI and SBA-16 CI and fits well to the Langmuir isotherm equation. 2015-05-13T00:00:00Z