Browsing by Author "Ghemmit-Doulache, Naima"

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Caractérisation du pouvoir entartrant de l'eau de mer, étude de l'effet anti - dépôt de l'acide 2 - hydroxy , 4 - méthyl, benzyl, phosphonique par Chronoampérometrie, Impédance complexe et MEB
(2003) Ghemmit-Doulache, Naima
L'eau de mer est riche en calcium et magnésium ainsi son utilisation dans les circuits de dessalement provoque des dépôts néfastes sur les échanges thermiques, débit et même mécanique. Après avoir synthétisé un inhibiteur d'entartrage acide 2-hydroxy, 4-methy, benzyl, phosphonique nous avons suivi avec les méthodes électrochimiques son efficacité. L'utilisation des méthodes électrochimiques : la chronoampérométrie et l'impédance complexe nous ont permis d'étudier les cinétiques de formation de dépôt calcomagnésien en eau de mer, en absence et en présence de l'inhibiteur acide 2-hydroxy, 4-methy, benzyl, phosphonique, sur l'électrode à disque tournant en titane. Cette étude de déposition calcomagnésienne a été menée en imposant un potentiel -1.7 V/ECS, à 1500 rpm et aux températures 25, 55 et 85 °C. La structure de dépôt calcomagnésien sans et avec l'inhibiteur a été étudiée en observant les surfaces des couches de dépôt au MEB et en l'identifiant par analyse qualitative X. Sans l'inhibiteur, le dépôt couvre toute la surface de l'électrode surtout à 85 °C; le dépôt s'est colmaté sur toute la surface du métal. Avec l'addition de 26.5 ppm de l'inhibiteur, la texture de dépôt est totalement modifiée. A 85 °C l'acide 2-hydroxy, 4-methyl, benzyl, phosphonique inhibe totalement le dépôt sur le titane. La faible couche observée présente une dispersion uniforme de macropores avec quelques rares cristaux dégénérés
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.
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
Electrochemical behaviour of the titanium-seawater interface at the Cape-Djinet, Boumerdes thermal station : influence of the potential, temperature, and brine
(Taylor & Francis, 2015) Ghemmit-Doulache, Naima; Remli, Ali
Étude cinétique du dépôt calcomagnésien sur une électrode en Titane et mécanisme de détartrage, comparaison entre la méthode chimique et électrochimique
(2011) Ghemmit-Doulache, Naima
L'élévation de la température ainsi la vaporisation partielle de l'eau de mer sont responsables de l'entartrage des évaporateurs et surtout du réchauffeur de saumure de l'unité de dessalement. En effet, les tartres réduisent les sections de passage, dégradent les états de surface et augmentent les pertes de charge et par conséquent les dépenses énergétiques liées à la circulation de l'eau deviennent importantes. Lors de ce travail, nous avons utilisé différentes techniques chimiques et électrochimiques permettant une étude à la fois thermodynamique et cinétique du phénomène d'entartrage dans une eau de mer artificielle.L'étude de l'entartrage par voie électrochimique nous a permis de fixer le potentiel à -1.3 V/Ag-AgCl qui entraine ainsi des dépôts calcomagnésiens riche en CaCO3 et en Mg(OH)2 sur l'électrode en titane. Il a été démontré que la température peut favoriser prioritairement la formation de l'aragonite ou de la brucite en fonction du potentiel appliqué. L'ajout de fortes quantités en ions sulfate présente un effet d'inhibition sur la déposition calcaire, magnésienne et calcomagnésienne.L'utilisation du dégazage contrôlé a montré que la déposition calcaire est affectée par l'augmentation de la concentration en Ca2+. Les ions magnésium inhibent la déposition calcomagnésienne et l'ajout progressif du magnésium rend la surface de l'aragonite secondaire "ballon de rugby" plus striée. Enfin, l'augmentation de la concentration en ions sulfate a permis de diminuer la quantité du dépôt sur le verre alors que sur le titane le nombre de cristaux est plus important dont les tailles sont plus petites
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.
Olive Leaf Extract as a Potential Anti-Corrosion of Copper-Nickel in Natural Seawater
(Springer Science and Business Media, 2025) Bourouis, Douniazed; Ghemmit-Doulache, Naima; Bounechache, Foudil; Trari, Mohamed
This study investigates the phenolic composition of olive leaves from Skikda region (Northern Algeria), focusing on their therapeutic potential for diabetes and hypertension due to their high content of phenols, particularly oleuropein. The leaves were dried, micronized and characterized by FT-IR spectroscopy. The obtained powder was subjected to various extraction techniques, including microwave, Soxhlet, Ultrasound-Assisted Extraction (USAE) and traditional maceration. The extracted compounds were analyzed by gas chromatography-mass spectrometry (GC/MS) and Ultra-High Performance Liquid Chromatography (UHPLC) coupled with electrospray ionization-quadrature-time-of-flight mass spectrometry (ESI-Q-TOF-MS). The presence of olivetol and two oleuropein isomers, highlighted the rich phenolic profile of the leaves. The study also examines the efficacy of olive leaf extract, particularly from traditional maceration, to prevent corrosion in the Cu-Ni alloy (90/10) seawater, one of the most corrosive environments. The results showed a high inhibitory efficiencies of 96.8% for the highest concentration (S1) by Tafel and 93% for the lower concentration (S3) by Electrochemical Impedence Spectroscopy (EIS). Scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) analyses confirmed that the surface of the treated alloy remains free of corrosion, unlike the untreated alloy, which shows significant deterioration with a black corrosion layer attributed to the cuprite Cu2O. The study focuses on the identification of olivetol in olive leaf extract and its remarkable properties, for potential and preventive applications against corrosion
Recuperation of silver from wastewater of miroiterie of thenia (Algeria)
(2015) Ghemmit-Doulache, Naima; Morsli, Nassima; Slimani, Nadia
In Algeria, the nonexistence of silver mines makes it particularly rarer than its classification among the precious metals imposes its metal recuperation. The objective of this study is electrodeposition of silver ions of sludge from wastewater of miroiterie of SOMIVER Thenia. The process applied in this case is electrolysis of sludge formed in a glass cell containing two electrodes: a cathode made of aluminum and a graphite anode. An adjustable continue current source capable of delivering from 1 to 10 Amps, this causes the cathode reaction electrodeposition of silver. Therefore, we lead to precede by comparison determinations under the effect of weight of cathode. Its weighing before and after electrolysis, and weight difference, means that amount of silver accumulated. Second, we determined the characteristics of sludge by electrochemical aluminum interface (OCP linear voltammetry and electrochemical impedance spectroscopy) before and after electrolysis, this is made possible by Potentiostat PGZ 301. In the electrolysis of silvering solution it has proved that low currents from 0.5 to 4 A can get a good yield of deposit silver where ∆m increases linearly with increasing intensity of electrolysis current for a period of 30 minutes. By against, for electrolysis currents higher than 4 A we recorded decrease in the amount of silver
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%
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)
Transition-metal complexes of N,N′-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide : synthesis, characterization, biological activities, ADMET and drug-likeness analysis
(Elsevier, 2021) Belkhir-Talbi, Drifa; Ghemmit-Doulache, Naima; Terrachet-Bouaziz, Souhila; Makhloufi-Chebli, Malika; Rabahi, Amal; Ismaili, Lhassane; Silva, Artur M.S.
Coordination compounds of N,N’-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide (L1) were synthesized via the reaction of Cu (II), Co (II) and Zn (II) salts in molar ratio 1 : 1 in the presence of ammoniac as basic media. The Ligands and the complexes formed were characterized using FT-IR, UV–visible and fluorescence spectrophotometric analyses, mass spectrometry, elemental analyses and NMR spectroscopy. It was concluded that N,N’-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide (L1) coordinated as a mono ligand for all the complexes; it also coordinated via the –OH and –NH groups. The electrochemical behaviour of these compounds was determined by cyclic voltammetry. The synthesized compounds were screened for their antimicrobial and antioxidant activities. All the complexes except that of copper show good activities against the S. aureus and those of cobalt and zinc have very interesting diameters of inhibition but lower antioxidant activity than the ligand L1. Parameters drug-likeness and ADMET (Absorption, Distribution, Metabolism, and Excretion) properties have been calculated
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
Water quality control of three sites at kedarra barrage
(University of El Oued, 2021) Ghemmit-Doulache, Naima; Ouslimani, N.
Study aim is to monitor water quality at three sites at Keddara barrage witch located on territory of Boumerdes-Algeria. Physico-chemical, bacteriological and heavy metal analyses were carried out on waters feeding barrage site A, within barrage site B and those leaving barrage corresponding to pumping waters site C. Physical qualities of all three waters largely meet WHO standards. Chemical qualities Results showed that hardness is greater at site C. A mineralization with low nitrate, chloride, phosphate and ammonium contents. DCO/DBO5 ratio < 3 (for all three sites), indicating that source of water pollution is of organic origin. Analysis results of all three samples by SAA revealed traces of heavy metals which confirm good water quality. Keddara barrage waters are charged with total coliform bacteria, enterococcus and Escherichia-coli, so these waters require bacteriological treatment.