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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 Equilibrium and Kinetic Modelling of Astrazon Yellow Adsorption by Sawdust: Effect of Important Parameters(2010) Ouazene, Naima; Sahmoune, Mohamed NasserThis paper aims to investigate the sorption of Astrazon yellow (A.Y.) onto sawdust (Aleppo pine tree), a forest waste as that acts as a low-cost adsorbent. In our experiments, the batch sorption is studied with respect to solute concentration, contact time, adsorbent dose, particle size and pH. The adsorption process attains equilibrium within 300 minutes. The extent of dye removal decreased with increasing particle size and increased with increasing contact time, adsorbent dose and pH. The equilibrium data were analysed by the Langmuir and Freundlich isotherms. The characteristic parameters for each isotherm were determined. By considering the experimental results and adsorption models applied in this study, it can be concluded that equilibrium data were represented well by the Langmuir isotherm equation. Maximum adsorption capacity calculated at 293K was 81.8 mg/g. Five kinetic models (pseudo-first order, pseudo-second order, fractional power, Elovich and intraparticle diffusion kinetic equations) were used to predict the adsorption rate constants. The kinetics of adsorption of the basic dye followed both Elovich and pseudo-second order kinetics, and intraparticle diffusion was not the sole rate-controlling step. The effective diffusion of Astrazon yellow in sawdust according to Boyd Model was 24.22 .1012 m2/S. In order to reveal the adsorption characteristic of sawdust samples, SEM and FTIR spectra analyses were carried out. The results show that sawdust (Aleppo pine tree) can be an alternative low-cost adsorbent for removing cationic dyes from wastewater.Item Mass-transfer processes in the adsorption of cationic dye by sawdust(Wiley, 2012) Sahmoune, Mohamed Nasser; Ouazene, NaimaAdsorption kinetic and equilibrium studies of cationic dye namely, Astrazon Yellow (AY) from aqueous solution at various initial dye concentration (15–50 mg/l), pH (2–9), particle size <1600 μm on Aleppo pine-tree sawdust were studied in a batch mode operation. Batch studies revealed that the potential of Aleppo pine-tree sawdust in dye removal was dependant on initial pH and initial dye concentration. In order to select the main rate-limiting step in the overall uptake mechanism, a single external mass transfer diffusion model, Urano and Tachikawa model and intraparticle diffusion model were used. The external mass transfer rate constant β was found to be 8.5 10-5 m-1 at initial concentration 50 mg/l of AY and 1.14 10-4 m-1 at initial concentration 15 mg/l of AY. It was observed multi-linearity in the shape of the intraparticle diffusion plot. The two phases in the intraparticle diffusion plot suggest that the sorption process proceeds by surface sorption and an intraparticle diffusion stage. The effective diffusion coefficients Di were found to be 3.88 10-11 cm2/s and 4.2 10-11 cm2/s for initial concentration of AY of 15 mg/l and 50 mg/l respectively, indicating a poor intraparticle diffusion into Aleppo pine-tree sawdust . AY sorption onto sawdust was mainly located on the surface. The equilibrium isotherms were analysed using the Langmuir, Freundlich, Temkin and Elovich models. It was seen that the sorption data fitted to Langmuir, Freundlich, Temkin and the Elovich isotherms, but they were very well described by the Langmuir model.Item Evaluation of thermodynamic parameters for adsorption of heavy metals by green adsorbents(Springer, 2019) Sahmoune, Mohamed NasserThermodynamic parameters ΔG°, ΔH° and ΔS° are indicators of the possible nature of adsorption. This review summarizes the thermodynamic properties of metal adsorption by green adsorbents. Conclusively, the adsorption of heavy metals ions by green adsorbents is spontaneous in most cases (ΔG° < 0). Since the thermodynamic parameters were evaluated from very different adsorbent/adsorbate combinations, it is not possible to note a correlation between the corresponding enthalpy change (ΔH°) and entropy change (ΔS°) following adsorptionItem Performance of Streptomyces rimosus biomass in biosorption of heavy metals from aqueous solutions(Elsevier, 2018) Sahmoune, Mohamed NasserThe removal of heavy metals by Streptomyces rimosus has been the subject of many investigations. This review paper focuses on the removal of heavy metals from aqueous solution through Streptomyces rimosus, produced from pharmaceutical industry as solid waste, as adsorbent, and discusses the effect of various process parameters like pH, temperature, metal concentration etc., on the metal removal efficiency of this bacterium. The paper also evaluates the different kinetic, equilibrium, and thermodynamic models used in Streptomyces rimosus sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions are also discussed. The literature revealed that Streptomyces rimosus had a good affinity for binding lead and iron compared with other heavy metals. The adsorption of heavy metals is well described by Langmuir isotherm, which expresses the existence of monolayer adsorption. The kinetic data followed both pseudo first order and pseudo second order models. Thermodynamic studies showed spontaneous and exothermic nature of the sorption processes in most case. Dilute acids (HCl and H2SO4) are quite effective in desorption of heavy metals. Ion exchange played the chief role in the adsorption mechanism of metal, and carboxyl groups are mainly involved in this mechanismItem Adsorption of auramine-O using activated globe artichoke leaves : kinetic and isotherm studies(Chemic Publishing Company, 2017) Laribi, Kahina; Sahmoune, Mohamed NasserItem Adsorption of auramine-O using activated globe artichoke leaves : kinetic and isotherm studies(Chemic Publishing Company, 2017) Laribi, Kahina; Sahmoune, Mohamed NasserThe aim of this work was to study the removal of auramine-O (Au-O) from aqueous solution using powder prepared from globe artichoke leaves chemically activated with NaOH solution. The physico-chemical characteristics of the samples were performed and the characterization by FT-IR analysis has been carried out to examine the structure of globe artichoke leaves before and after activation. Scanning electron microscope was used to analyze the surface change of the globe artichoke leaves before and after adsorption of dye solution. 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 equilibrium data fitted very well to Langmuir model with maximum monolayer adsorption capacity of 344.8 mg g-1 at 298 K. This study shows that the globe artichoke leaves can be used as low cost alternative adsorbent for removal of auramine-OItem Potential of sawdust materials for the removal of dyes and heavy metals : examination of isotherms and kinetics(Taylor and Francis, 2016) Sahmoune, Mohamed Nasser; Yeddou, Ahmed RedaItem Effect of chemical treatment of the biomass fongic on the capacity of adsorption of the chromium(European Journal of Scientific Research, 2006) Sahmoune, Mohamed Nasser; Louhab, K.; Addad, J.; Goma, B.Heavy metals are present in different types of industrial effluent, being responsable for environmental pollution. Biosorption by the biomass fungic is a promising alternative method to treat industrial effluents, mainly because of its low cost and high metal binding capacity. In this paper we studied the effect of treatment at different concentration NaOH of the biomass fungic on the caracteristics of the biomass (morphology of the fungic biomass), and the capacity of adsorption of chromium. The analysis of the thermodynamic, the kinetics of adsorption, the spectra of infra-red spectra and the electron micrographs of the M.E.B. watch that these treatments, although resulting in apreciable weight reduction, also enhanced their capacity adsorption for chromium, while increasing the sorption kinetics. © EuroJournals Publishing, Inc. 2006Item Studies of chromium removal from tannery effluents by dead streptomyces rimosus(2008) Sahmoune, Mohamed Nasser; Louhab, Krim; Boukhiar, Aissa