Publications Internationales
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Item Thermodynamic and kinetics studies on adsorption of Indigo Carmine from aqueous solution by activated carbon(Elsevier, 2019) Harrache, Zahia; Abbas, Moussa; Aksil, Tounsia; Trarib, MohamedThe kinetic and equilibrium parameters of the quantitative adsorption for Indigo Carmine (IC) removed by commercial activated carbon (AC) were studied by UV–visible absorption spectroscopy. AC with a high specific surface area (1250.320 m2/g) was characterized by the Brunauer–Emmett–Teller (BET) method and point of zero charge (pzc). The effect of the initial dye concentration (10–60 mg/L), contact time (0–90 min), pH (1−12), agitation speed (0–600 rpm), adsorbent dose (1–10 g/L) and temperature (298–323 K) were determined to find the optimal conditions for a maximum adsorption. The adsorption mechanism of Indigo Carmine onto AC was studied using the first pseudo order, second pseudo order and Elovich kinetics models. The adsorptions kinetic were found to follow a pseudo second order kinetic model with a determination coefficient (R2) of 0.999. To get an idea on the adsorption mechanism, we applied the Webber-Morris diffusion model. The equilibrium adsorption data for Indigo Carmine on AC were analyzed by the Langmuir, Freundlich, Elovich, Dubinin and Temkin models. The results indicate that the Langmuir model provides the best correlation at 25 °C (qmax = 79.49 mg/g) and Dubinin at 40 °C (qmax = 298.34 mg/g). The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters such as free energy (ΔG° = −0.071 to −1.050 kJ/mol), enthalpy (ΔH° = 28.11 kJ/mol), entropy (ΔS° = 0.093 kJ/mol·K) and activation energy (Ea) of 51.06 kJ/mol of adsorption. The negative ΔG° and positive ΔH° values indicate that the overall adsorption is spontaneous and endothermic.Item Oxygen diffusion and migration in clean and defective uranium nitride UN (0 0 1) surfaces(Elsevier, 2018) Zergoug, T.; Abaidia, Seddik-El-Hak; Nedjar, A.This study focuses on the diffusion of atomic and molecular oxygen through the uranium mono-nitride UN (0 0 1) surface. The adsorption of oxygen at the most favorable sites has been checked on different surface states namely: clean surface and surfaces containing defects such as inclusion atoms. Inclusions atoms are positioned at a uranium U atom vacancy or at a nitrogen N atom vacancy location of the UN (0 0 1) surface. Neptunium, plutonium, protactinium, silver and neodymium which are the most probable nuclear reactions (n, U) products have been selected as U atom substitute. Some light elements such as carbon, chromium and silicon were used to replace an N atom. The first principle calculation, based on Density Functional Theory (DFT) was used, taking into account the Generalized Gradient Approximation (GGA) and the Projector-Augmented Wave (PAW) to describe the exchange-correlation functional. The purpose of this work is to verify the oxygen adsorption energy variations performed across all the studied surfaces. The most favorable sites of UN (0 0 1) clean and defective surfaces to oxygen O atom diffusion were preliminary identified. In the second step, atomic dynamical Potential Energy Surface (PES) was used to study the interaction between O atom and UN (0 0 1) surfaces at these sites. Finally, Nudged Elastic Band (NEB) method was used in order to investigate the migration of O atom through the UN (0 0 1) surfaces. The results show that at the bridge site, the adsorption and incorporation energies of oxygen atom on and in the UN (0 0 1) surfaces respectively, do not substantially vary with the type and position of the studied impurities. But, at the N vacancy site, the adsorption energy of the O atom decreases practically when UN (0 0 1) surfaces contain inclusion atoms compared to the clean surface case. Furthermore, the NEB calculations show discrepancies for the Minimum Energy Path (MEP) during the migration of the O atom at the bridge site through the studied UN (0 0 1) surfaces and depending on the type and position of the added impurities. Among the studied MEPs, protactinium is found to be the most suitable barrier to the diffusion of oxygen through the UN surface as an inclusion on UN (0 0 1)Item An enhanced immobilization of BSA biomolecule on anionic hydrogels: Swelling and adsorption modeling(Springer International Publishing, 2017) Angar, Nour Elhouda; Aliouche, DjamelThe three-dimensional structure of hydrogels plays a leading role in several areas of applications. The hydrogels are more and more used as systems of immobilized and controlled release of biomolecules in biotechnology and bio-pharmacy industries. To improve protein adsorption capacity in poly(acrylamide) hydrogels, maleic acid co-monomer was included into the reaction mixture during hydrogel synthesis. So, hydrogels of poly(acrylamide) and its copolymers with diprotic maleic acid were prepared by copolymerization and chemical crosslinking with N,N′-methylene bis-acrylamide. Swelling behavior in distilled water, in physiological saline and in bovine serum albumin (BSA) solutions was studied. Influence of initial BSA concentration on hydrogel swelling and BSA adsorption was investigated. The high amount of maleic acid present in the hydrogels has a significant effect on the swelling behavior and BSA adsorption. Results showed that the pH sensitivity of hydrogels resulted in the high amount of adsorbed BSA. The adsorption isotherms were described by Langmuir and Freundlich models. The thermodynamic parameter (ΔG ads 0) was determined for all obtained hydrogels. We demonstrated the favorable character and reversibility of the BSA adsorption processItem Removal of toxic methyl green (Mg) in aqueous solutions by apricot stone activated carbon – equilibrium and isotherms modeling(Taylor & Francis, 2018) Abbas, Moussa; Aksil, Tounsia; Trari, MohamedApricot stone activated carbon (ASAC), was powdered, activated and to be used as effective adsor-bent to remove the dyes from aqueous solutions through batch experiments under operational factors namely, pH, contact time, adsorbent dose, initial dyes concentration and temperature. The physico-chemical, morphological and structural properties of the adsorbents were characterized by scan-ning electron microscope (SEM) and X-ray diffraction (XRD) instruments. Different kinetic modelsindicated that the adsorption is well described by the pseudo-second order model. The isotherms of methyl green (MG) adsorption on ASAC were obtained and correlated with various models. The smaller RMSE values for the Langmuir and Dubinin-Radushkevic models indicated the best fitting; the mono layer adsorption capacity of MG was found to be 148.478 mg g–1 at 21°C and 88.11 mg g–1 at 46°C at pH 10. The thermodynamic functions showed spontaneous and endothermic MG adsorption. In conclusion, the adsorbent prepared from apricot stone (ASAC) was found to very effective and suitable adsorbent for reactive dyes removal from aquatic environment, due to its simple and cheap preparation, easy availability and good adsorption capacity.Item Removal of gentian violet in aqueous solution by activated carbon equilibrium, kinetics, and thermodynamic study(SAGE Publications, 2019) Abbas, Moussa; Harrache, Zahia; Trari, MohamedThe quantitative kinetic and equilibrium adsorption parameters for chlorure de méthylrosaniline (gentian violet, crystal violet) removed by commercial activated carbon were studied by UV–visible spectroscopy.Activated carbon with a high specific surface area 1250 m2/g was characterized by the Brunauer, Emmett et Teller (BET) method and the zero charge point pH (pzc). The adsorption properties of both activated carbon with gentian violet were conducted at variable stirring speed 100–700 trs/min, adsorbent dose 1–8 g/l, solution pH 1–14, initial gentian violet concentration 5–15 mg/l, contact time 0–50 min, and temperature 299–323 K using batch mode operation to find the optimal conditions for a maximum adsorption. The adsorption mechanism of gentian violet was studied using the pseudo-first-order, pseudo-second-order, and Elovich kinetic models. The adsorption kinetics was found to follow a pseudo-second-order kinetic model with a determination coefficient (R2) of 0.999. The Weber–Morris diffusion model was applied for the adsorption mechanism. The equilibrium adsorption data of gentian violet were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation (qmax = 22.727, 32.258 mg/g at 26 and 40°C, respectively). The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters, i.e. free energy (ΔG° = − 2.30 to −5.34 kJ/mol), enthalpy (ΔH° = 36.966 kJ/mol), entropy (ΔS° = 0.131 kJ/mol K), and activation energy (Ea) 40.208 kJ/mol of gentian violet adsorption. The negative ΔG° and positive ΔH° indicate that the overall adsorption is spontaneous and endothermic in natureItem Adsorption and dissociation of H2S on the anatase TiO2 (100) surface: DFT + U study(Iop science, 2018) Nehaoua, N.; Belkada, R.; Tala-Ighil, RazikaThis paper discusses the adsorption and dissociation of the hydrogen sulfide (H2S) molecule on the titanium dioxide surface. They were studied by density function theory (DFT). The GGA + U approach was used to analyze the adsorption behavior of the H2S molecule on the TiO2 anatase (100) surface. The results presented include adsorption energies, structural and electronic properties, charge transfer and work function. Different adsorption configurations are considered with coordination of H2S at the surface (Ti5c, (Ti5c)2, O2c and O3c sites). The calculated adsorption energies are -0.31, -0.28, -1.14 and -5.66 eV. The most favorable adsorption sites lead to the dissociation of H2S into HS and H, where the S atom of HS binds to Ti5c or O2c atoms, leaving a dissociated H atom bonded to another O2c site. Analysis of Bader's charges reveals a significant charge transfer between the molecule and the surface of the TiO2 anatase. The adsorption process reduces the work function and bandgap of the system, which improves the photocatalytic properties of TiO2Item Kinetic and thermodynamic studies of the ammonium ions adsorption onto natural Algerian bentonite(Taylor & Francis, 2016) Angar, Yassmina; Djelali, Nacer-Eddine; Kebbouche-Gana, SalimaAdsorption processes are the most recommended complementary techniques applied in the wastewater treatment owing to their low economic cost, recyclability, efficiency and low power consumption. Clays known for this treatment are aluminosilicate minerals which contain different exchangeable ions on their surfaces. In the structure of bentonite surface, several cations have the exchange ability such as calcium, sodium, magnesium and potassium. This propriety is responsible for the adsorption of several cationic water pollutants. In this study, natural bentonite particles of 80 μm in diameter were considered and kept stirring at 200 RPM in a contaminated solution with ammonium ions. The effect of contact time and temperature showed that at an optimal temperature of 30°C and during a short stirring time of 50 min, the removal efficiency could reach its maximum of 53.36%. The kinetic study of the ammonium adsorption reaction on natural bentonite allowed concluding that the reaction is obeyed to the first-order model. Determination of various thermodynamic parameters suggests that the reaction is spontaneous and exothermicItem Preparation and characterization study of an olive pomace - polyaniline composite conductor in the recovery of heavy metals by electrosorption and adsorption(Aljest, 2018) Babakhouya, Naouel; Abdouni, M.; Louhab, K.In this work, we have prepared a new composite material based on olive pomace (OP) and polyaniline (PANI) by the in situ-polymerization chemical method, demonstrated the ability of our material to conduct current through electrical conductivity tests.We used the spectral analysis techniques to characterize the material as well as Laser Particle Size and scanning electron microscopy to show that the PANI was successfully attached to OP.We have applied our new material in the recovery of Hexavalent Chromium by carrying out electrosorption tests at a positive potential imposed. We compared the recovery with chemical adsorption under the same conditionsItem Valorization of peach stones to high efficient activated carbon : synthesis, characterization, and application for Cr(VI) removal from aqueous medium(Taylor & Francis, 2018) Khemmari, Fariza; Benrachedi, KhaledItem Comparative study of the adsorption of paracetamol from aqueous solution on olive stones and date pits(Taylor & Francis, 2018) Medjdoub, Fatma; Louhab, Krim; Hamouche, Aksas