Publications Scientifiques
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Item 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 Adsorption of malachite green (MG) onto apricot stone activated Carbon (ASAC)-Equilibrium, kinetic and thermodynamic studies(2017) Abbas, Moussa; Aksil, TounsiaThe adsorption of malachite green (MG) onto apricot stone activated carbon (ASAC) in a batch adsorber and the effects of contact time, initial pH, agitation speed, adsorbent dosage and initial dye concentration on the MG adsorption by the ASAC have been studied. It was observed that under optimized conditions up to 23.94 mg/g at 25 oC and 88.5 mg/g at 70 oC could be removed from solution. Kinetic parameters; rate constants, equilibrium adsorptin capacities and correlation coefficients, for each kinetic equation were calculated and discussed. It was shown that the adsorption of MG onto ASAC could be described by the pseudo second-order equation. The experimental isotherm data were analyzed using the Langmuir, Freundlich, Temkin, Elovich and Redlich-Peterson equations. Adsorption of MG onto ASAC followed the Langmuir isotherm. The evaluation of thermodynamics parameters such as the negative Gibbs free energy and positive enthalpy change indicated respectively the spontaneous and endothermic nature of the reaction and the chimisorption of the sorption processItem Kinetic and equilibrium studies of coomassie blue G-250 adsorption on apricot stone activated carbon(2015) Abbas, Moussa; Cherfi, Abdelhamid; Kaddour, Samia; Aksil, Tounsia; Trari, MohamedThe preparation of Activated Carbon from Apricot Stone (ASAC) with H3PO4 and its ability to remove the Coomassie Blue (CB) used in textile industry from aqueous solutions are reported in this study. The FTIR spectroscopy is used to get information on interactions between the adsorbent and CB. A series of contact time experiments were undertaken in stirred batch adsorber to assess the effect of the system variables. The results were discussed and showed that ASAC can be used in the wastewater treatment. A comparison of two models on the overall adsorption rate showed that the kinetic of adsorption was better described by the pseudo-second order model. The adsorption isotherms of CB onto ASAC are determined and correlated with common isotherms equations. The smaller RMSE values obtained for the Freundlich model indicate the better curve fitting; the monolayer adsorption capacity of CB is found to be 10.09 mg/g at temperature 22.5 °C and 98.022 mg/g at temperature 50 °C and pH ~ 2. The thermodynamic parameters indicate the spontaneous and exothermic nature of the adsorption process. The positive value of the entropy (ΔS) clearly that the randomness in decreased at the solid-solution interface during the CB adsorption onto ASAC, indicating that some structural exchange may occur among the active sites of the adsorbent and the ions. The activation energy (66.161 kJ/ mol) indicates that the chemical adsorption was predominantItem Adsorption in simple batch experiments of Coomassie blue G-250 by apricot stone activated carbon—Kinetics and isotherms modelling(Taylor & Francis, 2015) Abbas, Moussa; Cherfi, Abdelhamid; Kaddour, Samia; Aksil, TounsiaThe preparation of an activated carbon from apricot stones (ASAC) with H3PO4 activation and its ability to remove the Coomassie blue (CB) from aqueous solutions are reported in this study. The spectroscopy method is used to get information on interactions between the functional groups of the adsorbent and the CB. Batch adsorption experiments were first undertaken to assess the effect of various parameters on the removal efficiency of CB. It was observed that under optimized conditions up to 98.022 mg/g could be removed from solution at 50°C. The equilibrium experimental data were analysed using Langmuir and Freundlich isotherm equations. An error-based statistic study showed that the isotherm data are well described by the Freundlich model. The suitability of the kinetic models for the adsorption of CB onto ASAC was also investigated. It was found that the adsorption kinetics of the dye obeyed pseudo-second-order kinetic model. The evaluation of thermodynamics parameters such as activation energy of adsorption (Ea: 66.161 kJ/mol) predicted the chemisorption nature of the sorption process. The negative Gibbs free energy (−ΔG° = 15.21–19.27 kJ/mol) and negative enthalpy change (ΔH° = −55.088 kJ/mol) indicated, respectively, the spontaneous and exothermic nature of the reaction