Publications Scientifiques
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Item Adsorption Behavior of Methylene Blue Onto Activated Coconut Shells: Kinetic, Thermodynamic, Mechanism and Regeneration of the Adsorbent(SAGE, 2024) Abbas, Moussa; Trari, MohamedAdsorption 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.Item Removal of Amoxicillin From Wastewater Onto Activated Carbon: Optimization of Analytical Parameters by Response Surface Methodology(SAGE Publications Inc., 2024) Abbas, Moussa; Trari, MohamedAntibiotics 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).Item Understanding the rate-limiting step adsorption kinetics onto biomaterials for mechanism adsorption control(SAGE Publications Ltd, 2024) Sahmoune, Mohamed Nasser; Abbas, Moussa; Trari, MohamedBiomaterials are a class of porous materials that have been widely exploited over the past two decades. However, the implications of controlling adsorption by rate-limiting steps are still not adequately established. Identifying the rate-limiting step is a promising approach for the design of adsorption systems. In this review, we study in detail the rate-limiting step of the adsorption of dyes in aqueous media on biomaterials to rationalize the factors governing the rate-limiting step involved in the adsorption process using empirical kinetics and mass transfer models. This knowledge is then applied to identify the best fit of these models to study the rate-controlling step involved in the adsorption process, which is crucial for the design of the adsorption system. This review first studies the limiting step of adsorption of dyes in an aqueous medium on biomaterials. Kinetic modeling is used to better understand the rate control step involved in biosorption. Generally, the equations used are empirical models of kinetics and mass transfer and the biomaterials come from the following categories: agricultural and industrial waste, algae, fungi, bacteria, and plants. In most adsorption studies reported in this review, the pseudo second-order model was found to be best suited for fitting the kinetic data of dyes on biomaterials, indicating that chemisorption is the rate-limiting step that controls adsorption. Concerning the diffusion effects of mass transfer, intraparticle diffusion is among the most often used models to examine the rate-limiting step which is controlled by both film diffusion and intraparticle diffusion. The first takes place when the external transfer is greater than the internal transfer while the opposite occurs in the case of porous diffusion. However, the majority of works do not study the real step of controlling the overall adsorption kinetics, namely, film diffusion or intraparticle diffusion.Item 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 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 Kinetic, equilibrium and thermodynamic study on the removal of Congo Red from aqueous solutions by adsorption onto apricot stone(Elsevier, 2015) Abbas, Moussa; Trari, Mohamed