Publications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/13

Browse

Author: search.filters.author.Ghemmit-Doulache, NaimaHas files: Yes

Search Results

Now showing 1 - 7 of 7
  • No Thumbnail Available
    Item
    Insight into the adsorption of acid fuchsin using CoAl layered double hydroxide: Central composite design, kinetics, isotherms and thermodynamic studies
    (Elsevier, 2023) Meguellati, Zineb; Ghemmit-Doulache, Naima; Brahimi, Razika
    Massive amounts of wastewater contaminated by hazardous and synthetic dyes are produced by the textile industry. Therefore, it is crucial to develop innovative techniques for removing these pollutants. In the present study, CoAl- LDH with excellent adsorption ability was synthesized via coprecipitation method at ambient temperature. The surface morphology and composition of the resulted compound were evaluated using several methods including X-ray diffraction (XRD), Fourier Transform Infrared spectrometry (FTIR), scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), differential thermogravimetry (DTG), and Differential scanning calorimetry (DSC). The results given by Brunauer, Emmett and Teller theory (BET) showed that the material has a specific surface area of 48 m2.g−1 and pore volume of 0.42 cm3.g−1. The as-synthesized material was tested for the acid fuchsin removal from an aqueous medium and the impact of several parameters was investigated. The experimental parameters such as the pH, the initial concentration, the adsorbent dose and the time were optimized using the central composite response surface methodology. The optimal adsorption capacity is attained at pH = 4.5, Initial concentration C0 = 96.71 ppm, adsorbent dose d = 0.40 g.L−1 and time t = 180 min. The adsorption process fitted well with the pseudo-second order reaction, and followed Langmuir adsorption isotherm providing a considerable Langmuir adsorption capacity of 384.6 mg. g−1. The effect of different temperatures reveals the thermodynamic parameters, i.e., the free Gibbs energy ΔG° (−4.86 to −1.16 kJ.mol−1), enthalpy change (ΔH° = 79.69 kJ.mol−1) and entropy (ΔS° = 137.61 JK−1.mol−1), the negative ΔG° and positive ΔH° values signify that the fuchsin acid adsorption is spontaneous and endothermic.
  • No Thumbnail Available
    Item
    Study of scale inhibitor SI-4497 effect on calcareous deposit
    (Desalination Publications, 2021) Ghemmit-Doulache, Naima; Bourouis, Douniazed; Bounechache, Foudil
    Calcareous deposits in water desalination generate serious problems and lead to considerable economic losses. The aim of this study is to investigate the inhibition of calcareous deposits using polyphosphonate (scale inhibitor SI-4497), which is an ideal additive for desalination operations. We studied the recovery rate of titanium electrode, in the presence and absence of this inhibitor, using chronoamperometry. A cathodic potential of –1.3 V/SCE (SCE – saturated calomel electrode) is used at 1,000 rpm and at 20°C, 40°C, 60°C, 80°C. Levich’s law is verified before and after 1 h of electrodeposition in presence of an inhibitor. It was found that electrode recovery decreases with the addition of 3.5 ppm polyphosphonate (scale inhibitor SI-4497), resulting in an efficiency of 63.65%
  • No Thumbnail Available
    Item
    The effect of surface treatments on the electrochemical behavior of titanium alloy in seawater by electrochemical impedance spectroscopy (EIS)
    (2015) Ghemmit-Doulache, Naima; Benserradj, S.
    Seawater contains many minerals, dissolved gases, including oxygen O2 cellular organisms, suspended solids and sediments that sometimes impart high turbidity. Chemical and biological characteristics of seawater make it a particularly aggressiv materials in particular titanium. Physico-chemical interactions between a metal material and its environment can lead to corrosion of material. Deterioration of metal due to microbial activity is called biocorrosion or corrosion induced by microorganisms (CIM). Because of its economic and environmental importance, CIM has been extensively over past five decades and several models studies have been proposed to explain the mechanisms biocorrosion observed. Many sectors are a facilities, plant thermal (heat exchangers). Biofilm formation on walls of conduits considerably reduces heat transfer, this is particularly important in case of heat exchanger tubes. We noted that electrode moves corrosion potential to more cathodic values. And more, the short stay of titanium in natural seawater, corrosion potential varies around - 250 mV/Ag/AgCl, and then it reaches less cathodic values to longer residence time. Electrochemical impedance measurements showed the presence of one loop relative to the capacitive charge transfer phenomenon of metal/passive layer. Keywords: Natural seawater, Titanium, OCP, Electrochemical impedance spectroscopy
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Effect of marine biofilm on the electrochemical behavior of stainless steel and titanium
    (International Congress of Chemistry and Environment, 2015) Ghemmit-Doulache, Naima; Azzouni, B.; Meriouli, A.
  • No Thumbnail Available
    Item
    Verification of Levich law. determination of hydrogen currents accoring to temperature and polarization potential during calcareous deposition
    (2011) Ghemmit-Doulache, Naima; Khireddine, H.; Si Salah, D.
    The complexity of calcareous deposits processes in a marine environment results in simultaneous effects of the following parameters: temperature, polarization potential, interfacial pH, chemical composition, etc.. The comprehension of these processes implies studies in artificial seawater and a follow-up of the parameters by voltamperometry and chronoamperometry. Calcareous deposits electrochemically are very often used to follow up the evolution of scale deposition in desalination circuits. Again, the scale formation is brought about by electrochemical reduction of dissolved oxygen. The hydroxyl ions formed on the metallic surface engender a rise of interfacial pH which causes calcareous deposition (CaCO3 and Mg(OH)2). This reaction goes with reaction of hydrogen evolution which could disrupt the formed deposit. A study is carried out in a solution of seawater ASTM without calcium and without magnesium (so that the deposit will not be formed) on a titanium rotating disk electrode monitored between 300 and 1000 rpm. Study shows that Levich criterion is checked for the four values of selected potential on the diffusion plateau and a very cathodic polarization potential and a high temperature favors hydrogen current rate
  • No Thumbnail Available
    Item
    Study of the antideposit effect of 2-Hydroxy-4-methylbenzylphosphonic acid
    (2009) Ghemmit-Doulache, Naima; Khireddine, H.; Bourouina, M.; Boudissa, N.
    The scale inhibitor, 2-hydroxy-4-methylbenzylphosphonic acid (HMBP) appears efficient for desalination plants of sea water. A concentration of 26.5 ppm (131 μmol/L) prevents the calcareous magnesium deposits. The anti-scale effect of this inhibitor is achieved by chronoamperometry at imposed potential and complex impedance. SEM allows observation of the calcareous magnesium deposits with and without inhibitor 2-hydroxy-4-methylbenzylphosphonic acid (HMBP)