Browsing by Author "Chergui, A."

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Comparative study of biosorption of Cu+2, Ni+2, Cd+2, Zn+2 and Co+2 ions on the Pleurotus mutilus biomass
(Université M'hamed Bougara de Boumerdès, 2018) Madani, A.; Selatnia, A.; Chergui, A.; Yeddou, A.R.; Nadjemi, B.
In this study the biomass Pleurotus mutilus was used for the biosorption of Cu2+, Ni2+, Cd2+, Zn+2 and Co+2 ions. The effect of different parameters such as contact time, adsorbate concentration, pH of the medium and temperature were investigated. The sorption capacities were in the order of Cd2+ > Zn+2 > Co+2 >Cu2+ > Ni2+ . This order can be explained by their different values of affinities respectively. In order to prediction of the rate controlling step(external or internal mass transfer) , Boyd model was used in all case. Results showed that the external mass transfer is the rate controlling step. Different thermodynamic parameters such as enthalpy and entropy and change in standard free energy have also been evaluated and it has been found that the reaction was spontaneous and exothermic in nature. The Freundlich, Langmuir, Temkin and Dubinin-Raduskuvich adsorption models were used for the mathematical description of the biosorption equilibrium.
Copper, Zinc And Nickel’s Removal By Bentonite Clay: Case Study In Mono And Multicomponent Systems
(Université M'Hamed Bougara Boumerdes, 2019) Hamdache, F.; Chergui, A.; Halet, Farid; Yeddou, A.R.
The main purpose of this work is the Copper, Zinc and Nickel’s removal from mono and multi-metal ions aqueous solution using an Algerian bentonite without treatment. The bentonite is characterized using SEM, XRD and X-ray fluorescence. The effect of initial pH and contact time are studied. Under mono and multicomponent systems, the kinetic studies performed at pH 5, indicate that the adsorption follows a pseudo second order model. For both systems, the isotherm data are well correlated with Langmuir model. Whereas the maximum adsorption capacities follow the sequence’s order Cu > Zn > Ni. In the case of multicomponent system, the Cu(II), Zn(II) and Ni(II) adsorptions capacities (58.82, 19.53 and 6.56 mg/g) are lower than the obtained ones for the monocomponent system (58.48, 49.02 and 31.74 mg/g). In addition to that, a mutual competitive effect is observed. Zn(II) and Ni(II) ions adsorption is also inhibited by Cu(II) ions with no change in the maximum Cu(II) adsorption capacity.
Kinetic and thermodynamic studies of methylene blue adsorption on sorghum stems
(ALJEST, 2020) Sifoun, Naima; Yeddou, A-R.; Nouri, L-H.; Chergui, A.; Nadjemi, B.
The Raw Sorghum stems have been studied as to adsorb Methylene Blue from aqueous solution by batch technique. The effects of different parameters such as adsorbent dose, initial pH, ionic strength, contacttime and dye initial concentration have been studied. To describe the adsorption kinetics, five models were applied. Kinetic parameters for each adsorption kinetic equation were calculated and discussed. The experimental isotherm data were analyzed using three models. The recovery of methylene blue adsorption has been exceeded 80%.The pseudo-second order kinetic model adequately describes the kinetic data with high determination coefficient (R2=0.99). Langmuir isotherm model fits better than Freundlich and Temkin models for all temperatures studied, and the maximum methylene blue uptake was observed as 27.67 mg/g at 313 K. The estimated values for ΔG°were -2.56, -3.31and -3.78 kJ/mole at 295, 303 and 313 K respectively. The enthalpy changes ΔH°and entropy ΔS°of adsorption were 17.19 kJ/mole and 67.24 J/mole.K, respectively.