http://dspace.univ-setif.dz:8888/jspui/handle/123456789/1418 Tue, 05 May 2026 02:02:42 GMT 2026-05-05T02:02:42Z http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3078 Titre: Adsorption of Cd and Pb metal ions onto chelating resin and their application in removal of lead from battery factory wastewaters Auteur(s): Addala, Abdelhamid; Belattar, Noureddine Résumé: Lead is one of the most used metals in various factory activities. The contamination of soil and water with the metal has become a real or major environmental and public health problem or concern. Therefore, removal this toxic metal from wastewaters is a great challenge to protect environment and people. This study aims to assess adsorbing properties by batch procedure of a chelating ion exchange functionalized by iminodiacetic acid group toward Pb and Cd by varying the concentration of these metals at different contact times and at a given pH. In the second step, this adsorbent support is used in dynamic condition in a column for the removal of Pb particularly from effluents from an industrial unit. Finally, the exchange material, packed in bed, is regenerated in order to establish its reusability and efficiency in removing process. The adsorption rate of Pb and Cd onto the chelating adsorbent increases as the initial content and time contact increase and the maximum adsorption capacity is found to be 137.40 and 90.40 mg/g at the plateau of saturation, respectively. In a column, the adsorbing support or material reduce totally the concentration of loaded Pb in effluents during the two first cycles. During the third cycle, the removal power is still good and the content of Pb in the washing is reduced from 22 mg/L to 0.014 mg/L which is lower than the law's discharge levels. The regeneration of the support is achieved by 10 volume bed of 1 M HCl during thirty minutes at least. These results demonstrate clearly the effectiveness of the chelating adsorbent in removing lead from the effluents of the factory and its reusability in numerous cycles after a regeneration stage Tue, 22 Jan 2019 00:00:00 GMT http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3078 2019-01-22T00:00:00Z http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3077 Titre: On the electrochemical activity ofβ-lead dioxide in sulfuric acid solution: a comparative study between the chemical and electrochemical routes Auteur(s): Derafa, I; Zerroual, L; Matrakova, M Résumé: β-Lead dioxide is prepared by chemical and electrochemical routes. The chemical sample is obtained by dissolving lead tetra-acetate in distilled water at room temperature. The electrochemical sample is prepared by oxidizing cured plates in sulfuric acid with 1.05 g cm −3 specific gravity. The two powders are indexed asβ-PbO2. The sample prepared by chemical route presents smaller crystallite size. When cycling the two powders up to 100 cycles between 0.5 and 1.5 V versus Hg/Hg2SO4reference electrode, the electrochemical sample presents higher values of anodic and cathodic peak current densities and higher discharge capacity. Thermal analysis and electrochemical techniques are used to explain this difference in activity between the two samples. Tue, 22 Jan 2019 00:00:00 GMT http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3077 2019-01-22T00:00:00Z http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3076 Titre: Electrochemical, optical and morphological properties of poly (N-vinylcarbazole/TiO 2) and (N-vinylcarbazole/aniline)/TiO 2 copolymer prepared by electrochemical polymerization Auteur(s): Bouriche, Ouahiba; Bouzerafa, Brahim; Kouadri, Hicham Résumé: Poly (N-vinylcarbazole) (PVK) and a new copolymer, PVK/polyaniline (PANI), have been successfully prepared by electrochemical polymerization of N-vinylcarbazole (NVK) and NVK/aniline from acetonitrile medium and LiClO4 supporting electrolyte. Composite thin films were studied by cyclic voltammetry (CV) in LiClO4/acetonitrile solutions on an indium tin oxide (ITO) electrode. The influences of concentration of titanium dioxide (TiO2) on the electrochemical properties of these composite materials were also investigated. The results of scanning electron microscopy (SEM) confirm the presence of TiO2 in the composite, which consequently modifies the morphology of the film significantly. Topographical analysis has shown that TiO2 nanoparticles (NPs) affect the morphology of thin films (roughness). The analysis of the voltammograms of PVK and of (PVK+PANI) before and after the addition of TiO2 at different concentrations shows a redox couple which was not observed in the absence of TiO2. The impedance spectroscopy study shows that the resistance of the PVK and (PVK+PANI) films decreases with increasing of TiO2 concentration, and this in turn contributes to a good conductivity of the film. The optical characterization of the composites has been carried out by UV-Vis absorption and photoluminescence (PL) spectroscopy and it was noted that the samples (PVK+10⁻² TiO2) exhibited high transmittance (83%) in the visible region and a low gap value (2.69 eV) which confirms that this material can be used in a photovoltaic cell. This is explained by the introduction of the donor levels in the band gap of PVK by the TiO2, due to an effective doping Mon, 21 Jan 2019 00:00:00 GMT http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3076 2019-01-21T00:00:00Z http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3075 Titre: THE INFLUENCE OF TITANIUM DIOXIDE IN THE PVK MATRIX ON ANTI-BACTERIAL PROPERTIES, ELECTRICAL RESISTANCE AND RESISTANCE TO UV RADIATION Auteur(s): BOURICHE, Ouahiba; BOUZERAFA, Brahim; KOUADRI, Hicham; DJAOUT, Ouarda Résumé: In the present study the poly (N-vinylcarbazole) (PVK) is doped with nano-crystalline titanium dioxide (TiO2). The solutions of the PVK-TiO2 and neat PVK in the DMSO were prepared, followed by a gradual evaporation of the solvent until the mixture became viscous. The viscous solution was drop-cast onto a pre-cleaned glass substrate (ITO). A polymer thin film was formed after slow solvent evaporation under ambient conditions for 12h. Thin films of PVK-TiO2 composites show a porous microstructure (SEM). The complexation and the ultraviolet resistance of the composite were confirmed by Fourier transform infrared spectroscopy (FTIR) and UV-Visible studies. The antibacterial activity was tested with various concentrations, 10⁻²M, 3.10⁻²M and 5.10⁻²M of doping, with Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus. The electrical resistance of the samples of PVK and these complexes is based on the Automatic Mapping Four Point Probe System. Moreover, the TiO2 based Poly (N-vinylcarbazole) (PVK) exhibited a remarkable variation at higher concentrations as compared to that of the pure poly (N-vinylcarbazole) film. The antimicrobial activity against gram negative and gram positive bacteria increased with the increase in the concentrations of TiO2 and the maximum inhibition of bacteria growth was observed in PVK-TiO2(5.10⁻²M) composites with Escherichia coli. This is due to the higher concentrations of TiO2, activated surface area and better dispersion of TiO2 on PVK. The results of SEM confirm the presence of TiO2 in the composite, which consequently modifies the morphology of the film significantly. Mon, 21 Jan 2019 00:00:00 GMT http://dspace.univ-setif.dz:8888/jspui/handle/123456789/3075 2019-01-21T00:00:00Z