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Sdiri A.,University of Tsukuba | Higashi T.,University of Tsukuba | Hatta T.,Japan International Research Center for Agricultural science | Jamoussi F.,Center National Of Recherches En Science Des Materiaux Cnrsm | Tase N.,University of Tsukuba
International Journal of Global Environmental Issues | Year: 2012

This study focused on the removal of Pb(II), Cd(II), Cu(II), and Zn(II) using reagent solutions by natural limestone in a batch system. The sorbent, collected from the Late Cretaceous limestone beds, Tunisia, was characterised by X-ray diffraction (XRD), chemical analysis (XRF) and infrared spectroscopy (FTIR). XRF showed that the studied limestone contained high amount of calcium carbonates. XRD confirmed the presence of quartz along with the sharp peaks of calcite. FTIR spectra indicated that limestone was mainly composed of calcite, confirming the results of XRD and XRF analyses. Preliminary adsorption tests indicated that high removal efficiency could be achieved by limestone. The presence of impurities enhanced the adsorption capacity. Kinetic experiments showed that the sorption of metal ions best fitted the second order kinetic model with equilibration time of 60 min. These results suggested that the Campanian-Maastritchian limestone could be used for the removal of toxic metals from wastewaters. Copyright © 2012 Inderscience Enterprises Ltd. Source

Mellah B.,Center National Of Recherches En Science Des Materiaux Cnrsm | Lee Y.H.,University of Ulsan | Kim D.I.,Kyungwoon University | Cho J.H.,Kosin University | Kim Y.,Kosin University
Journal of Inclusion Phenomena and Macrocyclic Chemistry | Year: 2015

A first-generation calix-dendrimer 1 suitable as a multidentate ligand for metal-ion binding was prepared from 1,3,5-tris(aminomethyl)-2,4,6-trimethylbenzene as the dendrimer core and p-tert-butylcalix [4] arene monomethyl ester as a repetitive branch, and characterized by spectroscopic techniques. © 2015 Springer Science+Business Media. Source

Jaouadi M.,University of Tunis | Jaouadi M.,Center National Of Recherches En Science Des Materiaux Cnrsm | Hbaieb S.,University of Tunis | Guedidi H.,University of Savoy | And 3 more authors.
Journal of Saudi Chemical Society | Year: 2016

An activated carbon was prepared by phosphoric activation of olive pomace and further oxidation by nitric acid. Another carbon was obtained from β-cyclodextrin dehydration in concentrated sulfuric acid. A composite of the oxidized activated carbon and the carbon from β-cyclodextrin was prepared. The four materials were characterized by N2 adsorption-desorption measurements, X-ray diffraction, infrared and Raman spectroscopies, elemental analysis, "Boehm" titration and measurements of pH of the point zero charge. The obtained adsorbents were tested for boron adsorption in aqueous solution. Despite their lowest specific surface areas, the composite carbon and the amorphous carbon from cyclodextrin dehydration showed the highest boron adsorption uptake (1.41 and 1.68mg·g-1) compared to the raw (1.05mg·g-1) and oxidized (0.95mg·g-1) activated carbons. The surface chemistry particularly rich in phenolic groups was responsible for the high boron adsorption uptake of the carbon composite and the amorphous carbon, both prepared through cyclodextrin dehydration. © 2016 King Saud University. Source

Akir S.,Center National Of Recherches En Science Des Materiaux Cnrsm | Ghrib T.,University of Dammam | Daoudi K.,University of Sharjah | Gaidi M.,University of Sharjah
Journal of Alloys and Compounds | Year: 2016

In this study, undoped and Fe doped nanostructured Zinc oxide thin films were synthesized by simple and low cost co-precipitation and spin-coating technique. Surface morphology and crystalline structure of the deposited films were investigated by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) techniques. XRD analysis demonstrated that the films were polycrystalline with the hexagonal phase. From SEM investigations, the surface morphology of the deposited films was found to depend on Fe concentration. The obtained optical measurements indicated that Fe doping decreases the optical transmission and shift the optical gap to 3.08 eV for 0.5 at.% Fe content. An optimum Fe concentration of 0.5 at.% was found to lead to the highest photoconduction sensitivity of the ZnO films. The photocurrent enhancement response was explained by a better charge separation and collection efficiency under visible light illumination. © 2016 Elsevier B.V. All rights reserved. Source

Triki M.,Center National Of Recherches En Science Des Materiaux Cnrsm | Ksibi Z.,Tunis el Manar University | Ghorbel A.,Tunis el Manar University | Medina F.,Rovira i Virgili University
Journal of Sol-Gel Science and Technology | Year: 2011

Catalytic wet air oxidation of an aqueous solution of p-hydroxybenzoic acid was conducted over ruthenium catalysts (1 wt%) supported on CeO 2-Al 2O 3 aerogels mixed oxides at 140 °C and 50 bars of air. We study the effect of the amount of CeO 2 in the catalyst. We found that the optimal cerium content in the Al 2O 3 support was 20 wt%. The activity of the Ru/Al 2O 3 and Ru/CeO 2 was also tested for comparison. It was found that the addition of CeO 2 on the alumina support improves the activity of Ru catalysts. The activity of the samples decreases in the following order: Ru/Ce-Al (20) > Ru/Ce-Al (10) > Ru/Ce-Al (5) ≈ Ru/Al 2O 3 > Ru/CeO 2. Samples characterization was performed by means of N 2 adsorption-desorption, XRD, UV-Vis, TPR, SEM and TEM. © 2011 Springer Science+Business Media, LLC. Source

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