Publications Scientifiques

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    Adsorption Behavior of Methylene Blue Onto Activated Coconut Shells: Kinetic, Thermodynamic, Mechanism and Regeneration of the Adsorbent
    (SAGE, 2024) Abbas, Moussa; Trari, Mohamed
    Adsorption techniques are widely used to remove some classes of pollutants from waters, especially those which are not easily biodegradable. The removal of Methylene blue (MB), as a pollutant, from waste waters of textile, paper, printing and other industries has been addressed by the researchers. The aim of this study is to eliminate MB by Activated Coconut Shells (ACS) produced at low cost by adsorption in batch mode. The ACS was characterized by the FTIR spectroscopy and point of zero charge (pHpzc: 5.06). Some examined factors were found to have significant impacts on the MB uptake of ACS like the initial dye concentration Co (40-120 mg/L), solution pH (2-8), ACS dose (1-12 g/L), agitation speed (50-500 r/min), particles size (1.0- 1.2 mm) and temperature (298-333 K). The best capacity was found at pH 6 with an adsorbent dose 8 g/L, an agitation speed 200 r/min and a contact time of 60 min. Modeling Kinetics and Isotherms shows that the pseudo-second-order kinetic model with R2 (0.935 -0.998) and Langmuir adsorption isotherm model provide better fitness to the experimental data with the maximum adsorption capacity of 30.30 mg/g at 25°C. The separation factor R L (0.933-0.541) in the concentration range studied (10-120 mg/L) shows a favorable adsorption. The isotherms at different temperatures have been used for the determination of the free energy ΔG ° (198-9.72 kJ/mol); enthalpy ΔH ° (82.082 kJ/mol) and entropy ΔS o (245.689 J/K mol) to predict the nature of MB adsorption process. The positive values of (ΔG o ) and (ΔHo ) indicate a non-spontaneous and endothermic MB adsorption with a chemisorption. The adsorbent elaborated from Coconut Shells was found to efficient and suitable for the removal of MB dye from aqueous solutions, due to its availability, low cost preparation and good uptake capacity.
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    Removal of Amoxicillin From Wastewater Onto Activated Carbon: Optimization of Analytical Parameters by Response Surface Methodology
    (SAGE Publications Inc., 2024) Abbas, Moussa; Trari, Mohamed
    Antibiotics are widely used in veterinary and human medicine, but these compounds, when released into the aquatic environment, present potential risks to living organisms. In the present study, the activated carbon (AC) used for their removals is characterized by FT-IR spectroscopy, BET analysis and Scanning Electron Microscopy (SEM) to determine the physicochemical characteristics. Response surface methodology (RSM) and Box-Behnken statistical design (BBD) were used to optimize important parameters including pH (2-12), temperature (20-45°C), and AC dose (0.05-0.20 g). The experimental data were analyzed by analysis of variance (ANOVA) and fitted to second-order polynomial using multiple regression analysis. The optimal conditions for maximum elimination of Amoxicillin (Amox) are (Dose: 0.124 g, pH 5.03 and 45°C) by applying the desirability function (df). A confirmation experiment was carried out to evaluate the accuracy of the optimization model and maximum removal efficiency (R = 89.999%) was obtained under the optimized conditions. Several error analysis equations were used to measure goodness of fit. Pareto analysis suggests the importance of the relative order of factors: pH > Temperature > AC dose in optimized situations. The equilibrium adsorption data of Amox on Activated Carbone were analyzed by Freundlich, Elovich, Temkin and Langmuir models. The latter gave the best correlation with qmax capacities of 142.85 mg/g (R2 = 0.999) at 25°C is removed from solution. The adsorption process is dominated by chemisorption and the kinetic model obeys a pseudo-second order model (R2 = 0.999).
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    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, Mohamed
    The 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 endothermic
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    Potential of titanium dioxide to remove bromothymol blue (BTB) in aqueous solution by batch mode Adsorption–Kinetic, isotherm and thermodynamic studies
    (Springer, 2023) Abbas, Moussa
    The adsorption is widely used to remove certain classes of pollutants from water, especially those that are hardly biodegradable and dyes represent one of these problematic groups. The removal of bromothymol blue (BTB) from wastewater using TiO2 was studied in batch system. The adsorbent TiO2 has a specific surface area of 400 m2/g, a mean crystallites sizes (5–10 nm), and pHpzc equal to 6.5. TiO2 is stable over the whole pH range and constitutes a good compromise between efficiency and stability (in both acidic and basic media), therefore, the use of other additives is not necessary. Its non-toxicity and low energy required for its activation (E ~ 3 eV) as well as its low cost for most of the applications envisaged make it advantageous. The influence of effective variables such as solution pH (1–10), contact time (0–60 min), initial BTB concentration (5–40 mg/l), adsorbent dose of TiO2 (0.2–2 g/l), and temperature (20–60 °C) on the adsorption efficiency was examined, while the BTB content was determined by UV–Vis spectrophotometry. The optimal pH, adsorbent dose, and contact time for the efficient removal were found to be 10, 0.2 g/l, and 30 min, respectively, and the adsorbent was characterized by the BET analysis and point of zero charge (pHpzc). Among the different kinetic models, the experimental data of the BTB removal are well fitted with the pseudo-first-order kinetic model with a high determination coefficient. The evaluation of the fitness of equilibrium data by various conventional isotherm models, based on the R2 value as criterion, show the successful applicability of the Langmuir model for the interpretation of experimental data with a maximum adsorption capacity (qmax) of 27.02 mg/g at 20 °C and R2 of 0.997. The adsorption isotherms at different temperatures have been used for the determination of the free energy (ΔGo = 2.1808 to—1.0981 kJ/mol), enthalpy (ΔHo = 20.74 kJ/mol), and entropy (ΔSo = 65.58 J/mol/K) indicate that the overall adsorption is spontaneous and endothermic in nature
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    Thermodynamic and kinetics studies on adsorption of Indigo Carmine from aqueous solution by activated carbon
    (Elsevier, 2019) Harrache, Zahia; Abbas, Moussa; Aksil, Tounsia; Trarib, Mohamed
    The 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.
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    Adsorption of methyl green (MG) in aqueous solution by titanium dioxide (TiO2) : kinetics and thermodynamic study
    (Springer, 2021) Abbas, Moussa
    Adsorption techniques are widely used to remove certain classes of pollutants from waters, especially those that are not easily biodegradable. In this respect, the removal of Methyl green (MG) from waste water using TiO2 was studied in batch system. This research was carried out to evaluate the capability of TiO2 toward the water treatment relevant to organic MG at batch conditions. The effects of contact time (0–60 min), initial pH (3–11), agitation speed (100–500 rpm), temperature (25–45 °C), adsorbent dosage (0.02–6 g/L), and MG concentration (50–200 mg/L) on the MG adsorption by TiO2 have been studied. The adsorption kinetics in view of four kinetic models, i.e., the pseudo-first-order Lagergren, pseudo-second-order, intra-particle diffusion and Elovich models, was discussed. The adsorption of MG is well described by the pseudo-second-order equation with the best determination coefficient (R2 = 0.999). The experimental isotherm data were analyzed by different models; the adsorption follows the Langmuir and Temkin models, providing a better fit of the equilibrium data. The batch adsorption experiments were carried out to optimize the physical parameters on the MG removal efficiency, and it has been found that 384.615 mg/g at 25 °C is removed. The positive value of the activation energy (Ea = 14.1813 kJ/mol) indicates the endothermic nature and clearly that the randomness is increased at the solid–solution interface during the MG adsorption onto TiO2, indicating that some structural exchange occurs among the active sites of the adsorbent and the MG species
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    Mass transfer processes in the adsorption of Lead (Pb2+) by apricot stone activated carbon (ASAC) : isotherms modeling and thermodynamic study
    (Springer, 2021) Abbas, Moussa
    In 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 nature
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    Removal in batch mode experiment of Methylene Blue onto trimming Wood of Orange Tree –Equilibrium and Kinetics Studies –
    (ALJEST, 2018) Sifoun, Naima; Abbas, Moussa; Yeddou, A. R.; Nouri, L.; Nadjemi, B.
    In the present study, adsorption of Methylene Blue (MB) from aqueous solution was investigated using an adsorbent derived from Trimming Wood of Orange Tree (WOT). The used adsorbent was analyzed using FT-IR and SEM techniques.The adsorption of MB was carried out using a batch system and the effects of adsorbent dose, initial pH, ionic strength, contact time, initial concentration and temperature on the adsorption capacity of adsorbent were investigated. Kinetic parameters, rate constants, equilibrium adsorption capacities and determination coefficients, for each kinetic equation were calculated and discussed. It was shown that the adsorption of MB onto WOT could be described by the pseudo-second order kinetic. The experimental isotherm data were analyzed using the Langmuir, Freundlich and Temkin models. Adsorption of MB onto WOT followed the Langmuir isotherm for all temperatures studied and the maximum MB uptake was observed as 48.78 mg/g at 293 K. The evaluation of thermodynamics parameters such as the negative Gibbsfree energy and negative enthalpy change indicated respectively the spontaneous and exothermic nature of thesorptionprocess
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    Contribution of photocatalysis for the elimination of Methyl Orange (MO) in aqueous medium using TiO2 catalyst, optimization of the parameters and kinetics modeling
    (Desalination Publications, 2021) Abbas, Moussa; Trari, Mohamed
    The photo degradation of methyl orange (MO) in water onto TiO2 under UV irradiation is investi-gated. The parameters (MO concentration, catalyst dose, time, flux intensity and pH) influencing the degradation kinetics are studied. The equilibrium adsorption time of MO in the presence of TiO2 is reached after 50min of contact. Addition of H2O2 and NaCl at concentrations ranging from 100 to 500ppm shows that the percentage of the photo degradation decreases with increasing the H2O2concentration. The best results are obtained for a concentration of 100mg/L, while NaCl has a neg-ative effect on the MO photo degradation. The photocatalytic degradation rate was favored at high MO concentrations in agreement with the Langmuir–Hinshelwood (L-H) model. The constants krand K for the MO photo degradation are found to be 0.048mgL/min and 16.246L/mg, respectively
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    Photolysis of bromophenol blue in aqueous solution under uv-irradiation: optimization of the parameters influencing the kinetics of degradation
    (Desalination Publications, 2021) Abbas, Moussa
    Although water purification technologies have advanced considerably, they still come up against certain recalcitrant molecules that are difficult to degrade, such as pesticides, dyes and other indus-trial or agricultural residues. The degradation by photolysis of bromophenol blue (BPB), a textile dye, is studied under UV irradiation in the absence of the catalyst. Various parameters which influ-ence the kinetics of degradation have been studied, of which we can cite the pH, photonic intensity, BPB concentration and irradiation time. This study shows that the change in the chemical oxygen demand (COD) as a function of irradiation time and the mineralization of the solution occurs slowly. 4h of irradiation are necessary to observe 20% of COD which is determined by K2Cr2O7 oxidation in the presence of Ag+ as a catalyst, 96% of the organic compounds are oxidized under these con-ditions. The results show that the apparent rate constants of the BPB degradation augment linearly with the light flux. The discoloration rate of BPB solution augments with increasing pH until an optimum pH of 12, the degradation kinetics shows that the Langmuir–Hinshelwood model gives a better correlation. A total disappearance of BPB was observed after 150min of irradiation, indicating the effectiveness of direct photolysis in eliminating the dye. The apparent rate constants are deter-mined for the different parameters to confirm the validity of the model. The measurement of COD is a determination of organic matter which characterizes the amount of chemically oxidized sub-stances present in water. The results show that the apparent rate constants of the BPB degradation increase linearly with the photonic flux applied in the field of study