Publications Scientifiques
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Item An heterotrophic autotrophic denitrification approach for nitrate removal from drinking water by alfa stems(ALJEST, 2022) Benrachedi, Abdellah Lokman; Selatnia, A.; Belouanas, O.; Benrachedi, K.Biological denitrification of drinking water was studiedin up-flow laboratory reactors packed with alfa stems served as the sole carbon source as well as the only physical support for the microorganisms. The highest rates of denitrification were observed in fresh reactors during their first week of operation and the efficiency of the process declined therafter. In the first part, we have analysed the influence ohhydrolyc and volumic load to value the capacity of nitrate prurification in a down flow submerged biofilter then with an experimental design approach, we have analysed the qualitative and quantita-tive aspects of the effects of some factors, concentration of nitrate (80-200 mgl-1 and velocity (0.31 mh-1 on different responses like the apparentrate of denitrification as well as concentration of nitrite, nitrate and chemical demand on oxygen (DCO)in the reactor outlet.Item Preparation and Characterisation of adsorbent prepared from sewage sludge for removal of methylene blue(ALJEST, 2020) Djoumad, Sonia; Benrachedi, K.; Ladji, H.The objective of this study is to valorize an urban waste, the sludges from the wastewater treatment plant of Boumerdes/Algeria for the removal of methylene blue dye in aqueous solution by adsorption. The material made from this sludge has been characterized by various techniques: X-ray fluorescence microscopy (XRF), X- ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) to obtain information concerning their structures and their compositions.A systematic study of various parameters such as: effect of adsorbent dosage, contact time and initial dye concentration was carried out in order to optimize the ideal conditions for a good adsorption of the studied pollutant; especially the kinetics of adsorption.The exploitation of experimental results using different kinetic models and adsorption isotherms showed that the sludge has similar adsorption characteristics to those of activated carbon, which perfectly confirms the applicability of the activated sludge in the wastewater treatment.Item Feasibility study of adsorption of a textile dye on activated carbon prepared starting from the coffee grounds(Aljest, 2017) Mahdi, K.; Benrachedi, K.The activated carbon used in this study is prepared starting from the coffee ground whose abundance is important in our country and of which the use is often limited to food consummation. The physical characterization (porosity and surface) was determined by the adsorption of gas nitrogen to 77 K (BET), showed the presence of macropores (1.77 m2 /g), as well as the analysis by electronic scan microscopy MEB revealed the presence of a broad specific surface. The activated carbon obtained starting from the coffee ground was the object of an application to the aqueous medium for tests of elimination of a cation dye (methylene blue) used in the industry of textile, prepared synthetically. Several parameters were studied in order to optimize the ideal conditions for a good adsorption of the pollutant to study; in particular, the kinetics of adsorption, the effect of the initial concentration and the effect of the pH of the solution examined. The simulated isotherms of adsorption are very correctly described by the models of Langmuir and Freundlich. The percentage of discolouration reached is of: 99%. Therefore, one can conclude that this study showed that the coffee ground chemically activated can be used like new adsorbent for the water treatment contaminated by the textile dyesItem Continuous flow adsorption of orange acid II by coffee grounds in fixed bed column(University M'hamed Bougara - Boumerdes, 2020) Mahdi, K.; Benrachedi, K.A continuous fixed-bed column study on coffee grounds was carried out at bed depths 0.5-2 cm, flow rates of 0.18-0.53 mL.min-1with initial orange acid II concentrations of 20-100 mg.L-1 at room temperature. The breakthrough time of fixed-bed increased with the increase in bed depth, which permitted orange acid II to diffuse more into the interior of coffee grounds. But decreased with increasing initial concentration, and flow rate.The experimental data were in good agreement with both Thomas and Yoon-Nelson modelsItem Étude de l’adsorption d’un colorant cationique en milieu aqueux sur le charbon actif Issu de la ferula communis(2020) Messabih, S.M.; Benrachedi, K.; Makhlouf, M.; Belaid, K.D.; Bouchher, Omar; Louhab, K.La présente étude est consacrée à la préparation d’un charbon actif en poudre à partir des tiges broyées de la Ferula communis récoltées dans les coteaux de la wilaya de Tipaza au nord de l’Algérie. La matière végétale a été imprégnée à l’acide phosphorique (H 3 PO 4 ), puis carbonisée à 550°C dans un four à moufle. Les résultats obtenus par caractérisation du matériau adsorbant ont montré une importante porosité et une surface spécifique de 1377 m 2 /g. Les applications de l’adsorption du colorant rouge neutre sur le charbon actif, dans un milieu aqueux, ont révélé une capacité d’élimination de l’adsorbat allant jusqu’à 666 mg/g. L’étude thermodynamique a montré que le processus de l’adsorption est spontané et endothermiqueItem A comparative study of raw and treated peach stones for the adsorption of hexavalent chromium: characterization, kinetic and thermodynamic modelling(2018) Khemmari, Fariza; Benrachedi, K.In the last years, much attention has been focused on the use of low-cost adsorbents for the removal of heavy metals from wastewater. The present study consists of comparing the adsorption of hexavalent chromium in aqueous solutions by two adsorbents: raw peach stones (RPS) and peach stones activated carbon (PSAC). The characterization of the adsorbents was done by using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Comparative study was carried out using adsorption parameters such as contact time, adsorbent dose and solution pH in a batch system. Results show that pH is key parameter for adsorption optimization. The time necessary to attain adsorption equilibrium was found 120 min for PSAC in the pH range 2-5.6 and 240 min for RPS at pH 2 with maximum removal percentage greater than 97% for both adsorbents. The adsorption process followed the pseudo-second order kinetics. Thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption process for both adsorbents. Investigations carried out proved that RPS and PSAC are good potential adsorbents for the treatment of toxic hexavalent chromiumItem Chemical production and characterisation of activated carbon from waste 'coffee grounds'(Inderscience Enterprises, 2013) Mekarzia, A.; Namane, A.; Benrachedi, K.; Belhaneche-Bensemra, NaimaItem Removal of malathion from polluted water by adsorption onto chemically activated carbons produced from coffee grounds(2014) Bouchenafa-Saïb, N.; Mekarzia, A.; Bouzid, B.; Mohammedi, O.; Khelifa, A.; Benrachedi, K.; Belhaneche, N.Item Determination of the adsorption capacity of activated carbon made from coffee grounds by chemical activation with ZnCl2 and H3PO4(2005) Namane, A.; Mekarzia, A.; Benrachedi, K.; Belhaneche-Bensemra, Naima; Hellal, A.In order to evaluate the adsorptive capacities of granular activated carbon produced from coffee grounds by chemical activation, the adsorption of different phenols and acid and basic dyes, has been carried out. The comparison with a commercial activated carbon has been made. Adsorption isotherms of phenols and dyes (acid and basic) onto produced and commercial granular activated carbons were experimentally determined by batch tests. Both Freundlich [1] and Langmuir [2] models are well suited to fit the adsorption isotherm data. As a result, the coffee grounds based activated carbon may be promising for phenol and dye removal from aqueous streams