Publications Internationales
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Item Engineering of Natural Clay-Based Materials to Eliminate Toxic Pb(II): Kinetic, Thermodynamic, and Adsorption Mechanism(PHYSICOCHEMICAL PROCESSES AT THE INTERFACES Published, 2025) Abbas, Moussa; Trari, MohamedClimate change poses a threat to the water security by altering the precipitation patterns and other weather variables, which affect stream flow and freshwater availability. In this study, a soil and water assessment tool was used for the scarcity of blue and green water for future periods for sustainable management of freshwater resources away from lead pollution. Indeed, the presence of Pb2+ is an environmental problem and we have explored the use of natural phosphates (NP) as adsorbents for its elimination. The adsorbent NP was characterized by FTIR spectroscopy, scanning electron microscopy (SEM) and BET analysis. Batch adsorption experiments were performed to examine the effects of physical parameters namely the contact time, pH, stirring speed, temperature, adsorbent dose and initial Pb2+ concentration on the uptake capacity. Different models were used to fit the experimental data and to evaluate the kinetics, isotherms and thermodynamics of the Pb2+ adsorption. A high adsorption capacity of 66.66 mg/g was reached at 25°C and pH 6 and follows the Langmuir isotherm with a pseudo-second order kinetic. The adsorption is spontaneous and endothermic, indicating a structural exchange between NP and Pb2+ ions. Such results suggest that NP is a promising adsorbent for Pb2+ removal from wastewaterItem Engineering of Natural Clay-Based Materials to Eliminate Toxic Pb(II): Kinetic, Thermodynamic, and Adsorption Mechanism Study(PHYSICOCHEMICAL PROCESSES AT THE INTERFACES, 2025) Abbas, Moussa; Trari, MohamedClimate change poses a threat to the water security by altering the precipitation patterns and other weather variables, which affect stream flow and freshwater availability. In this study, a soil and water assessment tool was used for the scarcity of blue and green water for future periods for sustainable management of freshwater resources away from lead pollution. Indeed, the presence of Pb2+ is an environmental problem and we have explored the use of natural phosphates (NP) as adsorbents for its elimination. The adsorbent NP was characterized by FTIR spectroscopy, scanning electron microscopy (SEM) and BET analysis. Batch adsorption experiments were performed to examine the effects of physical parameters namely the contact time, pH, stirring speed, temperature, adsorbent dose and initial Pb2+ concentration on the uptake capacity. Different models were used to fit the experimental data and to evaluate the kinetics, isotherms and thermodynamics of the Pb2+ adsorption. A high adsorption capacity of 66.66 mg/g was reached at 25°C and pH 6 and follows the Langmuir isotherm with a pseudo-second order kinetic. The adsorption is spontaneous and endothermic, indicating a structural exchange between NP and Pb2+ ions. Such results suggest that NP is a promising adsorbent for Pb2+ removal from wastewaterItem Synthesis and characterization of MoO3: application to the photo production of oxygen under visible light(Springer, 2024) Koriche, Nesrine; Abbas, Moussa; Trari, MohamedOne of the most striking features of molybdenum oxide is the versatility of its catalytic properties, which are determined by the valence states of molybdenum and its coordination. It may be anticipated that MoO3 surface must contain catalytic sites which are active in different types of elementary steps. MoO3 was successfully synthesized by hydrothermal route at 400 °C, acquiring n-type conduction, due to oxygen deficiency. The single phase, elucidated by X-ray diffraction, crystallizes in an orthorhombic unit cell (Space Group (SG) Pbnm, N° 62) with a crystallite size of 12 nm. MoO3 is a direct band gap semiconductor with a forbidden band value of 2.93 eV where the electrical conduction occurs by low polaron hopping between mixed valences Mo+6/+5 with an activation energy of 0.14 eV. The thermo-power indicates n-type conduction, and confirmed by the capacitance-potential measurement; the latter gives an electrons density of 1.87 × 1020/cm3and a mobility of 1.77 × 10−6 m2/V.s. The flat band potential Vfb (0.11 VSCE) is determined from the capacitance measurement. The physical and chemical characterizations are correlated for the construction of the potential diagram in order to assess the photo electrochemical properties of MoO3 for the oxygen evolution. The valence band, is located above the O2/H2O potential ( ~ 1.3 VSCE), allowing O2 evolution upon visible light and the oxide is photocathodically protected against corrosion. An evolution rate of 0.13 mL/(mg. h) is obtained within 20 min. at optimal conditions (100 mg of catalyst and 50 °C).Item Elaboration of a new Activated Carbon derived from the Crown of Oak (ACOW) to removal the toxic Iodine: Kinetic, Isotherms modelling and Thermodynamics Study(Taylor & Francis, 2024) Aksil, Tounsia; Abbas, Moussa; Trari, MohamedThe current study aims to develop a new adsorbent material using oak crown and explore its effectiveness in removing I2 ions through a series of batch experiments. ACOW was characterised by zero charge (pHpzc) and FTIR spectroscopy. The impact of the initial I2 concentration (20-100 mg/L), temperature (25-55 °C), pH (2-14), adsorbent dosage (2-10 g/L), Stirring speed (100-900 rpm), particle size (100-2000μm) and contact time (0-30 min) on I2 adsorption was examined. The adsorption kinetic obeys the pseudo-second order model with a determination coefficient (R2) equal to 0.999. Adsorption follows the Langmuir equation well, with the best fit to the experimental data at equilibrium. A qmax value (= 103.606 mg/g) at 25°C and 120.773 mg/g at 55°C were eliminated under the optimised conditions, indicating homogeneous adsorption on the surface of the adsorbent. The thermodynamic parameters gave a negative free energy ΔGo (-3.445 to -5.629 kJ/mol), a positive enthalpy ΔHo (18.406 kJ/mol) and an activation energy Ea (= 22.599 kJ/mol), thus confirming the spontaneous and endothermic nature of adsorption of iodine on ACOW. The positive entropy ΔSo (0.0733 kJ/mol K) show increased randomness of the solid-liquid interface during the adsorption.Item Contribution of zeolite to remove malachite green in aqueous solution by adsorption processes : kinetics, isotherms and thermodynamic studies(SAGE, 2023) Abbas, Moussa; Trari, MohamedThe textile industry produces huge amounts of wastewaters containing synthetic dyes. In the textile industry, acid, basic, reactive, dispersed chemicals are widely used for dyeing. The aim of this study was to evaluate the adsorption of malachite green onto zeolite from aqueous solutions was realized in batch system. The adsorbent was characterized by the Fourier transform infrared spectroscopy, X-ray analysis, and zero point charge (pHzpc = 10.42). However, some examined factors were found to have significant impacts on the adsorption capacity of zeolite such as the initial malachite green concentration (Co), solution pH, adsorbent dose, agitation speed, particles size, and temperature. The best capacity was found at pH 8 with an adsorbent dose 0.2 g/l, an agitation speed 200 rpm and a contact time of 40 min. The kinetic adsorptions were found to follow rather a pseudo-second order kinetic model with a determination coefficient (R2) of 0.999. The equilibrium adsorption data for the malachite green adsorption onto the zeolite were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with a capacity qmax of 83.33 mg/g at 25°C. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters, namely the free energy (ΔG°); enthalpy (ΔH°) and entropy (ΔS°) to predict the nature of adsorption. The positive values of ΔG° and ΔH° indicate that the overall adsorption is not spontaneous and endothermic with a physisorption process. The adsorbent elaborated from the zeolite was found to be efficient and suitable for the elimination of reactive dyes from aqueous solutions, due to its availability of adsorption sites, low cost preparation, and good uptake capacityItem Synthesis, characterization and application of tetragonal BaTiO3-δ in adsorption and photocatalysis of congo red(Elsevier, 2023) Merrad, S.; Abbas, Moussa; Brahimi, R.; Bellal, B.; Trari, M.The synthesis by a simple approach of the deficient Barium Titanate BaTiO3-δ (BTO) crystallizing in a perovskite structure is reported along with the physicochemical properties. Thermal analysis (TG/DSC) was performed to elucidate the synthesis process. The X-ray diffraction (XRD), BET analysis, scanning electron microscopy (SEM-EDS) and electrochemistry were investigated. The catalyst revealed a single phase with a tetragonal symmetry obtained by treatment at 650 °C. The direct band gap (3.34 eV), obtained from diffuse reflectance spectroscopy (DRS), is assigned to the charge transfer O2-: 2p-Ti4+: 3d. The electrical characterization indicated a non-degenerate conductivity due to oxygen vacancies with an activation energy of 0.33 eV. The capacitance measurements indicated n-type behavior with a flat band potential (Efb) of − 0.43 V and a carrier concentration (ND) of 3.90 1018 cm−3. The photocatalytic process was elucidated by the electrical impedance spectroscopy (EIS). The performance of BTO was assessed by a combination of the adsorption of Congo Red (CR) followed by its degradation under UV light. The photodegradation kinetic was well fitted by a pseudo-first-order model with an abatement of 50% and 91% under UV and solar lights respectively. Different scavengers were used to evaluate the reaction mechanism and the radicals O2•- are the main reactive species of the CR oxidation. Four regeneration cycles demonstrated the catalyst stability. A degradation mechanism was established based on the scavengers effectItem Adsorption of malachite green onto walnut shells : kinetics, thermodynamic, and regeneration of the adsorbent by chemical process(Korean Fiber Society, 2023) Merrad, Samiya; Abbas, Moussa; Trari, MohamedThe textile industry produces huge amounts of wastewaters containing synthetic and toxic dyes. The aim of this study was to evaluate the adsorption of Malachite green (MG) onto Activated Carbon from Walnut Shells (ACWS) realized in a batch system. The effects of contact time, initial pH, stirring speed, particle size, temperature, adsorbent dose, and initial MG concentration on the adsorption capacity were investigated graphically for determining optimum conditions. The experimental isotherm data were analyzed by the Langmuir, Freundlich, Temkin, and Elovich models. The adsorption follows well the Langmuir equation, providing a better fit of the equilibrium adsorption data. Under optimized conditions, up to 154.56 mg/g at 25 °C and 370.37 mg/g at 45 °C were removed from the solution. The adsorption mechanism of MG onto ACWS was studied using the first-pseudo-order, second-pseudo-order, Elovich and Webber–Morris diffusion models. The adsorptions’ kinetic was found to follow rather a pseudo-second-order kinetic with a determination coefficient (R2) of 0.999. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters, i.e., the free energy ΔGo (0.802 to − 2.123 kJ/mol), positive enthalpy change ΔHo(18.547 kJ/mol), entropy (ΔSo = 0.064 kJ/molK), and activation energy (Ea = 14.813 kJ/mol). The negative ΔGo and positive ΔHo values indicate that the overall MG adsorption is spontaneous and endothermicItem Study of Congo Red removal from aqueous solution by using the deficient perovskite SrTiO3-δ under solar light(Elsevier, 2022) Merrad, S.; Abbas, Moussa; Brahimi, R.; Trari, M.The deficient perovskite SrTiO3-δ (STO) synthesized by nitrate route was identified by X-ray diffraction (XRD) and characterised by BET analysis, Attenuated Total Reflectance (ATR) and X-ray photoelectron spectroscopy (XPS). The latter enables us to determine the valence states of Sr2+, Ti4+ and O2−. A band gap of 3.32 eV was determined from the diffuse reflectance, assigned to the charge transfer O2−: 2p → Ti4+: 4s and white coloration of STO. The conduction band (−0.60 VSCE) and the valence band (2.72 VSCE) derived respectively from O2−: 2p and Ti4+: 4s orbitals are within the gap region of STO, thus generating O2·− and ·OH radicals responsible for the photo oxidation of Congo Red (CR), a hazardous dye. The photo-catalytic efficiency of STO was confirmed by the CR adsorption and degradation under solar light. Various physical parameters like the catalyst dose, dye concentration, initial pH, irradiation source and inhibitory effect of anions were studied. The synergetic effect of the electron injection from Congo Red into the STO-conduction band was confirmed by the electrochemical measurements through the photocurrent-potential plots and contribute to the photoactivity. An abatement of 62% and 97% are obtained under UV light and solar irradiation respectivelyItem Mass transfer processes in the adsorption of Lead (Pb2+) by apricot stone activated carbon (ASAC) : isotherms modeling and thermodynamic study(Springer, 2021) Abbas, MoussaIn the present study, batch experiments were carried out to elucidate the potential of apricot stone activated carbon ASAC to remove Pb2+ ions from aqueous solution. ASAC was characterized by Bruanauer, Emmett and Teller surface area S = 80.08 (m2/g), Fourier transform infrared spectroscopy and scanning electron microscopy. The effects of various process parameters such as initial pH (2–14), adsorbent dose (5–45 g/L) initial metal ion concentration (20–0 mg/L), contact time (0–90 min), agitation speed (100–700 rpm) and temperature (298–323 k) were investigated in their respective range and their optimum conditions were ascertained. The adsorption kinetics were analyzed by the pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion kinetic models. It was found that the adsorption of the metal ions followed pseudo-second-order kinetic model. The Adsorption isotherms were modeled with Langmuir, Freundlich, Temkin, Hasley and Harkins models and their isotherm constants were calculated. The Freundlich model fits the data with a monolayer adsorption capacity of 166.813 mg/g at pH 8. The thermodynamic parameters such as the Gibbs free energy, enthalpy and entropy were calculated to predict the nature of adsorption process. The calculated thermodynamic parameters showed that the adsorption of Pb2+ ions on ASAC is endothermic (ΔH0 = 121.38 kJ/mol) and not spontaneous (ΔG0 > 0) in natureItem Contribution of the electrocoagulation method in the removal of fluorine ions from aqueous solutions(2021) Abbas, MoussaPhotovoltaic technology has experienced a huge global economic boom in recent decades and a growing trend is expected in the future. This technology consists of the application of a number of processes including growth, oxidation, doping, metallization, etc. In order to reduce the fluo- ride content in the water below a threshold value that complies with the standards of industrial discharges or water intended for human consumption, various treatment techniques have been implemented. In this respect, electrocoagulation (EC) has been chosen in this study because of its performance compared to other methods. Wastewaters from surface treatment of silicon wafers are rich in fluoride and the lime precipitation is insufficient to comply with environmental standards. In this work, the EC technique, with Fe anodes, was used as an alternative for water purification. By coupling electroflotation to the electrocoagulation in the same cell, the separation of solid/liquid was significantly improved. To study the process performance, tests on the effect of the operational parameters such as current intensity, initial pH, nature of supporting electrolyte and its concentra- tion were carried out on synthetic solutions. The optimal values are: pHo = 4; current = 1.4 A and [NaCl] = 2 g/L. The removal efficiency of 62% was reached starting from an initial concentration of 35 mg/L. A total clarification of the synthetic solution was also obtained