Publications Nationales
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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 Autopsy of an old reverse osmosis membrane from Cap Djenet seawater desalination plant: case study of Algeria(2024-02-26) Talantikite, Sid-Ahmed; Benrachedi, K.In Algeria, as many other southern Mediterranean countries, the water’s resources remain limited. Today there is an increasing demand of drinking water and water requirements for irrigation and industry. Therefore, if we consider the saline water potential along the 1600Km coast, using reverse osomosis R.O process, the seawater desalination has been promoted such as an efficient alternative to provide security for drinking water. However, scaling and fouling are the most serious problems in the efficient operation of reverse osmosis systems and may leads to a loss of membrane performance then the necessary to replace the membranes. Therefore, in order to prolong its life and reduce the costs of producing drinking water, it is necessary to study the phenomenon of wear of the membrane using chemical analysis and membrane autopsy to analyze reverse osmosis fouling elements. Our work investigates phenomenon of wear of the membrane of the Cap Djenet seawater desalination plant. We focus on reverse osmosis membrane autopsy including an exhaustive study of the surface of the membrane and of the food-rejection spacer. We carried out several techniques including a chemical and microbiological analysis of the deposit which covered the surface of the membrane, tests to determine chemical oxidation (Fujiwara test), Tests with Scanning Electron Microscopy (SEM) with elemental analysis by X-ray Dispersive Energy (EDX) to study the atomic composition of fouling and an analysis of Fourier Transform Infrared (FTIR-ATR). The results obtained from the different analyses carried out on the autopsied elements indicate that the membrane from 1st position shows a high presence of fouling. The fouling on membranes show mainly characteristics: a mixture of protein derivatives related to biofilm, sodium chloride, iron, aluminosilicates and other elements commonly detected on sea water membrane fouling were identified. Due to the presence of fouling, membrane from first position showed a lower permeate flux than reference values. Considering these results, a review of plant pre-treatment and disinfection should be carried out in order to avoid the presence of the fouling components identified during the autopsyItem Alfa stems (stipatenacissima L as substrate for water denitrification(Université M'Hamed Bougara Boumerdes, 2018) Benrachedi, Abdellah Lokman; Selatnia, A.; Benrachedi, K.Biologicaldenitrification of drinking water was studied in up-flow laboratory reactors packed with alfa stems (stipatenacissima L) which 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 thereafter.The addition of fresh alfa stems brought about a temporary improvement of the denitrification performance and a regime of one weekly addition prevented the deterioration of a reactor which was operated for 5 months. The rate of denitrification was affected by the water velocity and decreased at velocities above 0.054 m.d-1 .Colour and soluble organic carbon associated with fresh alfa stems removed by adsorption on powdered activated carbonItem 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 Organic-inorganic hybrid zeolite silica materials by grafting of trimethylchlorosilane TMCS: part I: preparation and characterization(ALJEST, 2021) Bouchher, Omar; Benrachedi, K.; Makhlouf, M.; Messabih, S. M.; Louhab, K.The functionalization of our 13X zeolite was carried out by the post-synthesis method using an organosilane of the Trimethylchlorosilane type (TMCS) to obtain a more hydrophobic organic-inorganic hybrid zeolite. Our zeolite before and after grafting was characterized by different analysis techniques (XRD, FTIR, BET, and SEM). The XRD results of the grafted 13X zeolite, show that the functionalization does not destroy the crystal structure of the material. FT-IR analysis of the 13X zeolite before and after grafting confirms the grafting of our organosilane on the surface by the disappearance of the absorption band of the silanol groups at 980 cm-1 and the appearance of a band of absorption attributed to the vibrations of the trimethylsilyl Si (CH3) group at 2970 cm-1. The specific surface area of our grafted 13X has been reduced by 63.22 m2 / g thanks to the organic group which has been grafted on the external surface. According to SEM results, the morphology of the surface of our material was slightly modified after grafting. The results of various analyses demonstrated that the grafted 13X zeolite is successfully obtained using the post-synthesis method.Item Heterotrophic denitrification of contaminated groundwater using arachis hypogaea. l shell as carbon source(ALJEST, 2020) Benbelkacem, Ouerdia; Benrachedi, K.; Boumechehour, F.; Alioua, C.In this research, agricultural waste, Arachis hypogaea.L shells (peanut shells) was investigated for use as carbon source and biofilm carrier to remove nitrate from groundwater in batch reactor laboratory. The feasibility of heterotrophic denitrification of a high nitrate concentration groundwater using a natural carbon source was studied, a series of batch tests was performed with synthetic groundwater to exanimate the effects of various environmental and operational factors such as temperature, pH, initial nitrate concentration and finally the mass of powder of Arachis hypogaea.L shells on the rate of heterotrophic denitrification. A range of physic chemical analysis was performed including: Infrared, granulometry, spectroscopy atomic absorption and Scanning Electron Microscope (SEM).Decreasing initial pH decreased denitrification; however, increasing pH had little effect on denitrification rates. Using Arachis hypogaea.L shells as organic substratum of varying size classes, we found that finer-graine showed higher rates of denitrification compared to large grains, likely due to increased surface area per volume of substratum.Our findings suggest that Arachis hypogaea.L shell play an important role in N removal because they gave a reduction percentage of 90%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 Study of dispersion of brine water into coastal seawater by using a pilot(Aljest, 2015) Habet, Lila; Benrachedi, K.The technologies used in water desalination are accompanied by adverse environmental effects. There are several effects to be considered in desalination plants, such as the use of the land, the groundwater, the marine environment and noise pollution. Seawater desalination plants are located by the shoreline, to supply desalted water to the population of the main cities and for other uses. The construction of both the desalination plants and all the required infrastructure in coastal areas affects the local environment. For instance, the high salt concentration in the brine and several chemical products used in the desalination process are returned to the sea. Most impacts on the marine environment arise as a consequence of the brine discharge. In this paper, the objective of this work consists to study the dispersion of the brine discharges and its impact into marine environment. Then, a pilot used to study the different parameters of dispersion such as position of brine and depth and time of dispersion. Different points of brine (P1, P2, P3) were studied horizontally and vertically according to the ambient sea water. Experimental results obtained show that dispersion of brine in best then position of brine point is far and in down sea (P3)Item 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 endothermique