Browsing by Author "REHIMI, ZEHOUA"

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    Preparation and characterization of Fe3O4/MWCNTs nanocomposite. Application for the removal of organic dyes from aqueous solution.
    (University of 20 août 1955 Skikda, 2022-01-17) REHIMI, ZEHOUA; Chettah ,Abd Elhak
    Water purification technology is growing every day along with the developing of new nanomaterials in search of effective techniques to eliminate recalcitrant pollutants. This study investigated the efficiency of synthesized magnetic nanocomposite Fe3O4/MWCNTs in wastewater treatment against organic dyes contaminants. This nanomaterial was successfully synthesized via coprecipitation method. The characterization of Fe3O4/MWCNTs with X-ray diffraction (XRD); Fourier transform infrared spectroscopy (FTIR); Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) were carried out, which confirmed the presence of magnetite in the nanocomposite with good dispersion. The adsorption of Bromocresol Purple (BCP) anionic dye from aqueous medium was investigated in order to evaluate the adsorption capacity of the nanocomposite, which was around 296.52 mg.g-1. Kinetic study indicates that the equilibrium time was estimated to 90 minutes and the pseudo second order best suited this process. Isotherm modeling shows that the adsorption was fitted well by the Langmuir model. Thermodynamic study revealed that the sorption mechanism exhibits a spontaneous, exothermic and physisorption nature. The evaluation of the efficiency of Fe3O4/MWCNTs as a catalyst was studied for the removal of Crystal Violet dye (CV). According to the results obtained by rate constants and kinetic studies, the 3:1 weight ratio; the H2O2 concentration of 0.14 mol.L-1 and temperature of 318 K were the optimum conditions for the heterogeneous Fenton degradation of CV. Furthermore, the catalyst exhibited high stability because it can be reused for five successive cycles without any loss in its efficiency since the degradation rate remains almost complete. We also investigated the efficiency of Fe3O4/MWCNTs as a catalyst to eliminate CV in aqueous solution under polychromatic light (300-450 nm). The influence of certain systems on the degradation of CV was verified and compared, by calculating the degradation rate and rate constant. The degradation effect of the different systems is classified in the following order: CV+Fe3O4/MWCNTs+H2O2 > CV+H2O2 > CV+Fe3O4/MWCNTs > CV > CV+Fe3O4+H2O2 The Fe3O4/MWCNT+H2O2 system showed a very high degradation rate (over 90%) compared to the other systems. These results indicate the importance of Fe3O4/MWCNTs catalyst in water treatment, and show the possibility of its use at large scale.