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Author: search.filters.author.Derriche, Zoubir

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    Removal of Furfural from Aqueous Solutions by Adsorption Using Organobentonite: Isotherm and Kinetic Studies
    (2015-05-03) Mebrek, Ouassila Rachedi; Derriche, Zoubir
    Lubricant refineries are facing pollution problems associated with the occasional loss of furfural. This constitutes both an economic loss and an environmental hazard, especially for aquatic organisms. Some studies on the removal of furfural by adsorption onto hydrophobic polymeric resins (XAD-4 and XAD-7), activated carbon and the nanoporous material MCM-48 have been published, but none provides information on the adsorption of furfural onto clays. In the present work, we have studied the efficiency of sodium bentonite modified with the cationic surfactant cethyltrimethylammonium bromide (CTAB) in the adsorption of furfural. The structures of both natural and modified bentonites have been examined using XRD and FT-IR analyses. Adsorption studies were performed in a batch system, with the effects of various experimental parameters such as the contact time, the organobentonite concentration, pH, the initial furfural concentration and the temperature being evaluated. Kinetic results showed that furfural could be removed by CTAB–bentonite after contact for 6 h, with the adsorption process being well described by the pseudo-second-order reaction model. Furfural sorption onto CTAB–bentonite was characterized by a linear isotherm, with the adsorption capacity towards furfural being reduced by increasing temperature. A comparison of furfural adsorption capacities revealed that the capacities decreased in the following order: CTAB–bentonite > XAD-4 > XAD-7.
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    Lignosulfonate interleaved layered double hydroxide: A novel green organoclay for bio-related polymer
    (University of sciences and technology in Oran, 2014-04-19) Hennous, Mohammed; Derriche, Zoubir; Privas, Edwige; Navard, Patrick; Verney, Vincent; Leroux, Fabrice
    New organic inorganic layered double hydroxide (LDH) organoclays are assembled through coprecipitation with lignosulfonate (LS) interleaved inorganic host structure sheets. The biopolymer is found to accommodate the interlayer space adopting a bilayer molecular arrangement resulting in a basal spacing of 2.54 nm. However the crystallinity of the resulting bio-organoclay is weak, probably due to the difficulty of the inorganic sheets to be built on amorphous polymer chain, the latter inducing low structural ordering. An organoclay of composition Zn Al/LS is subsequently used as filler in three bio-related polyesters, poly(lactic) acid (PLA), poly(butylene) succinate (PBS) and poly(butylene adipate-co-terephthalate) (PBAT). Melt polymer extrusion using 5 wt.% organoclay loading yields polyester nanocomposite with a nanocomposite structure largely intercalated for both PLA and PBS (Δd (expansion)>6 nm) while a non miscible structure is obtained for PBAT. The incorporation of hydrophilic Zn 2Al/LS platelets decreases the water/polymer contact angle of about 10° for the LDH/LS PBAT composite only. A strong increase of the complex viscosity |η*| is observed for both nanocomposites Zn22Al/LS PLA and PBS compared to the polyester itself. This is explained on the basis of a chain extender behavior of the intercalated Zn Al/LS platelets towards polymer chains as evidenced on the Cole Cole representation showing an increase of the real viscosity in the low-ω region. In opposition a strong decrease in |η*| is observed for PBAT, underlining a plasticizing effect of the organoclay filler. Comparatively, the thermal stability of PLA is slightly enhanced with an increase of T2 value while PBS and PBAT bio-nanocomposites degrade at slightly lower temperature.