Browsing by Author "Benrachedi, K."

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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 carbon
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 autopsy
Biological denitrification heterotrophe of water with fixed biomass using alfa stems as energy source
(2010) Belouanas-Benbelkacem, O.; Benrachedi, K.
This work presents the results optimization of the biological process denitrification with fixed biomass using a consumable support (Alfa Stem). In the first part, the influence of hydrolyc and volumic load to value the capacity of nitrate purification in a down flow submerged bio filter was analyzed. Then with an experimental design approach, we have analyzed the qualitative and quantitative aspects of the effects of some factors: concentration of nitrate (80-200 mg L-1) and velocity (0.3-1.0 m h-1) on different responses like the apparent rate of denitrification, as well as concentration of nitrite, nitrate and chemical demand on oxygen in the reactor outlet
Chemical production and characterisation of activated carbon from waste 'coffee grounds'
(Inderscience Enterprises, 2013) Mekarzia, A.; Namane, A.; Benrachedi, K.; Belhaneche-Bensemra, Naima
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 chromium
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 models
Coupling ultrafiltration with adsorption on activated coffee for use as a reverse osmosis pretreatment
(2009) Benrachedi, K.; Bensouali, K.; Houchati, H.
The objective of this work was to replace the conventional pretreatment of reverse osmosis by coupling ultrafiltration with adsorption onto activated coffee-like adsorbent material. Adsorption was achieved on activated carbon prepared from a waste of coffee. A protocol of preparation is described as well as a characterization of the activated coffee. Physical and chemical activation was done. The development of a porous texture was proved by scanning electron micrography. A study of adsorption kinetic shows that the new material has a high adsorption capacity. The ultrafiltration–adsorption coupling is a good pretreatment for reverse osmosis
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
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
Evaluation of air pollution by heavy metals on bab El Oued zone of Algiers
(2010) Belamri, M.; Benrachedi, K.
The present study consists in analyzing the quality of the air in the capital. LVS pump (low volume sampler) was used for the collection of the samples in the district of Bab El Oued in Algiers characterized by the presence of a hospital and an incinerator of medical and different other waste as well as a strong density of traffic cars. The aerosols were taken at height of 3 m of the ground in total suspended particulate (TSP) mode. The samples have been analyzed by EDXRF (energy dispersive X-ray fluorescence). The experimental results show that the daily content of TSP are above limit of the target value 50 μg/m3. The TSP are respon-sible for the transport of toxic heavy metals such as Cd, Pb, Cr and Ni
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 dyes
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.
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%
Impact of debris from demolition of Boumerdes on the quality of groundwater
(2010) Benmenni, M.S.; Benrachedi, K.
The public discharge of Boumerdes city is at 5 km from downtown at Tidjelabine site and marly-calcareous formation. This formation shows crack porosity that facilitates pollution of groundwater reserves. The slope character of the field also favours the movement of pollutants. Leachates penetrating from the discharge towards the water table result in water quality deterioration. Chemical analysis carried out on samples from three piezometers show large concentration of chromium, zinc and lead, thus confirming the high groundwater deterioration. To assess the degree of pollution caused by this discharge, a comparison with other similar discharge was studied. This shows that the site is ancient of the discharge and is not stabilized yet and an acidic phase of anaerobic degradation is still going on. bacteriogical analysis carried out on groundwater show a microbiological contamination
Impact of earthquake demolition debris on the quality of groundwater
(2010) Benmenni, M. S.; Benrachedi, K.
Problem statement: Debris from construction or demolition/deconstruction processes have no significant impact on the environment as they are res-usable and inert. This has been also long admitted for solid waste generated by the demolition of damaged cities following violent earthquakes. Approach: This study is a contribution to the assessment of actual impact on the quality of groundwater of buried demolition debris from the city of Boumerdes, in the North of Algeria 5 years after the May 21st 2003 earthquake hit the region. The public discharge of Boumerdes city has been used as a temporary landfill. It is located about 5 km downtown of Boumerdes at the Tidjelabine site which is marly-calcareous formation. Leachate from the landfill was directly rejected in the receiving environment, where the soil is marly-calcareous type with cracks giving a variable permeability (10-2 m sec-1 to nearly 10-6 m sec-1) that facilitates infiltration of potential pollutants to the groundwater. The slope character (from 5-10%) of the field contributes to pollutants movement and may accentuate water quality deterioration. Three domestic wells (designated S1, S2 and S3) were selected in the vicinity of the landfill and served as piezometers. Leachate samples were taken from the landfill and evaluated. Results: Leachate analysis indicated organic matter with relatively high COD (1136 mg L-1 O2) and BOD5 (200 mg L-1 O2); whereas the pH yielded 7.65 thus indicating fermentation phase of the landfill. Heavy metal contents were beyond national standard limits except for Pb with 0.51 mg L-1 which is slightly higher than limit value of 0.5 mg L-1. More than five years after the creation of this landfill and despite its predominant C&D nature, these results showed that it was following a typical urban wastes decomposition scheme. Same analysis carried on water samples drawn from the piezometers yielded following results: acidic pH (6.88), acceptable values of target heavy metals concentrations except for Zn with 0.779 mg L-1. Additionally bacteriological cross analysis (membrane filter and multi-tube methods) showed groundwater contamination by total coliforms (1100/100 mL), fecal coliforms (11/100 mL) and fecal streptococci (1100/100 mL). Conclusion: These results proved that leachate had reached the first aquifer horizon about 10 m beneath soil surface. Prior to any remediation program, Management of Boumerdes Municipality is called to quickly implement a reuse and recycling program of the demolition debris in order to stop water reservoirs contamination source
Impact of earthquake demolition debris on the quality of groundwater in Boumerdes, Algeria
(2011) Benmenni, M.S.; Benrachedi, K.
This study is a contribution to the assessment of actual impact on the quality of groundwater of buried demolition debris from the city of Boumerdes, in the North of Algeria 5 years after the May 21st 2003 earthquake hit the region. Leachate analysis indicated organic matter with relatively high COD (1136 mg/L O2) and BOD5 (200 mg/L O2); whereas the pH yielded 7.65 thus indicating fermentation phase of the landfill. Heavy metal contents are beyond national standard limits except for Pb with 0.51 mg/L which is slightly higher than limit value of 0.5 mg/L. More than 5 years after the creation of this landfill and despite its predominant C and D nature, these results showed that it is following a typical urban wastes decomposition scheme. Same analysis carried on water samples drawn from the piezometers yielded following results: acidic pH (6.88), acceptable values of target heavy metals concentrations except for Zn with 0.779 mg/L. Additionally bacteriological cross analysis (membrane filter and multi-tube methods) showed groundwater contamination by total coliforms (1100/100 mL), fecal coliforms (11/100mL) and fecal streptococci (1100/100 mL)
Modification des performances des bitumes par incorporation d'un déchet ozonisé à base d'éthylène vinyl-acétate = Improvement of the performance of bitumen by addition of ozonized ethylene vinyl-acetate waste
(2007) Benrachedi, K.; Fahimi, A.; Fargere, T.; Delmas, M.; Gaset, A.; Pietrasanta, Y.; Boutevin, B.
Cette étude a pour objectif l'amélioration des performances d'un bitume par incorporation d'un déchet de polymère recyclé. La matière de base est un déchet à base d'éthylène vinyl-acétate lequel a subi au préalable une déréticulation par l'ozone en milieu solvant. L'incorporation du déchet ozonisé dans le bitume montre que la température de ramollissement et la pénétrabilité du bitume dépendent des conditions opératoires d'ozonisation. L'étude des facteurs d'ozonisation et de leurs influences sur la température de ramollissement, pénétrabilité et indice de pénétrabilité est réalisée par une matrice de Doehlert. Les résultats expérimentaux obtenus montrent que le bitume modifié a une bonne pénétrabilité ainsi qu'une température de ramollissement relativement élevée
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.
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.
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.