Browsing by Author "Aksas, Hammouche"

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    Adsorption of CD(II) ions from aqueous solution using mixed sorbents prepared from olive stone and date Pit
    (Asian network for scientific information, 2010) Babakhouya, Naouel; Aksas, Hammouche; Boughrara, S.; Louhab, K.
    The aim of this study is to remove Cd(II) ions from aqueous solutions by adsorption. Mixed sorbent prepared from olive stone and date pit, an agricultural solid by-product was used as adsorbent. The adsorption experiments of Cd(II) onto the mixture of olive stone and date pit were conducted at different parameters such as, percent of olive stone and date pit in the mixture, temperature, initial solution pH and initial Cd(II) concentration. Adsorption isotherms were obtained at different percent of olive stone and date pit in the mixture. This adsorption data was fitted with the Langmuir, Freundlich and Temkin isotherms. The thermodynamic of Cadmium sorption on the mixed sorbent follows the Langmuir model and the sorption capacity for cadmium increases when we add a small amount of olive stone at date pits (90% of date pits in mixture and 10% of olive stone) and a small amount of date pits at olive stone (90% of olive stone and 10% of date pits in mixture. In addition, the thermodynamic parameters, standard free energy (°G°), standard enthalpy (ΔH°) and standard entropy (ΔS°) of the adsorption process were calculated. The sorption of Cd(II) onto the mixture of olive stones and dates pit is spontaneous and presents an endothermic nature. The characteristics of the mixture were determined by the analysis of infra red spectral analysis. The results show that the mixture sorbent from olive stone and date pit is an alternative low-cost adsorbent for removing Cd(II)
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    Adsorption of chromium Ions from aqueous solution using mixed sorbents prepared from olive stone and date pit
    (Ebscohost, 2012) Aksas, Hammouche; Babakhouya, Naouel; Babaci, Hakima; Feggas, R.; Louhab, K.
    The aim of this study is to remove chromium ions from aqueous solutions by adsorption. Mixed sorbent prepared from olive stone and date pit, an agricultural solid by-product was used as adsorbent. The adsorption experiments of Cr onto the mixture of olive stone and date pit were conducted at different parameters such as, per cent of olive stone and date pit in the mixture, temperature, initial solution pH and initial chromium concentration. Adsorption isotherms were obtained at different per cent of olive stone and date pit in the mixture. This adsorption data was fitted with the Langmuir, Freundlich and Temkin isotherms. In addition, the thermodynamic parameters, standard free energy (ΔG°), standartd enthalpy (ΔH°) and standard entropy (ΔS°) of the adsorption process were calculated. The results show that the mixture sorbent from olive stone and date pit is an alternative low-cost adsorbent for removing chromium ions
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    Carbon nanotubes (CNTs) from synthesis to functionalized (CNTs) using conventional and new chemical approaches
    (2021) Lakhdar, Sidi Salah; Ouslimani, Nassira; Bousba, Dalila; Huynen, Isabelle; Danlée, Yann; Aksas, Hammouche
    Carbon nanotubes (CNTs) have emerged worldwide because of their remarkable properties enlarging their field of applications. Functionalization of CNTs is a convenient strategy to tackle low dispersion and solubilization of CNTs in many solvents or polymers. It can be done by covalent or noncovalent surface functionalization that is briefly discussed regarding the current literature. Endohedral and exohedral are conventional methods based on covalent and van der Waals bonding forces that are created through CNT functionalization by various materials. In this paper, a review of new approaches and mechanisms of functionalization of CNTs is proposed, including amidation, fluorination, bromination, chlorination, hydrogenation, and electrophilic addition. Our analysis is supported by several characterization methods highlighting recent improvements hence extending the range of applicability of CNTs.
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    Carbon nanotubes (CNTs) from synthesis to functionalized (CNTs) using conventional and new chemical approaches
    (Hindawi Limited, 2021) Salah, Lakhdar Sidi; Ousliman, Nassira; Bousba, Dalila; Huynen, Isabelle; Danlée, Yann; Aksas, Hammouche
    Carbon nanotubes (CNTs) have emerged worldwide because of their remarkable properties enlarging their field of applications. Functionalization of CNTs is a convenient strategy to tackle low dispersion and solubilization of CNTs in many solvents or polymers. It can be done by covalent or noncovalent surface functionalization that is briefly discussed regarding the current literature. Endohedral and exohedral are conventional methods based on covalent and van der Waals bonding forces that are created through CNT functionalization by various materials. In this paper, a review of new approaches and mechanisms of functionalization of CNTs is proposed, including amidation, fluorination, bromination, chlorination, hydrogenation, and electrophilic addition. Our analysis is supported by several characterization methods highlighting recent improvements hence extending the range of applicability of CNT
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    Design and optimization of a CPW-fed tri-band patch antenna using genetic algorithms
    (Applied Computational Electromagnetics Society (ACES), 2015) Fertas, K.; Kimouche, H.; Challal, Mouloud; Aksas, Hammouche; Aksas, R.; Azrar, Arab
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    Elimination of copper (II) in aqueous solution by adsorption on a pillared clay with polycations of aluminum and iron
    (International Congress of Chemistry and Environment, 2015) Cherifi-Naci, Halima; Louhab, K.; Aksas, Hammouche
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    Enviornmentalimpact of Algerian cement factories on fauna and flora
    (Asian Publication Corporation, 2017) Aksas, Hammouche; Boughrara, S.; Louhab, K.
    The aim of this study is to evaluate the environmental impact of atmospheric emission of two kinds of cement portland processes in the Algerian factories on fauna and flora. The first uses the dry process and is located in a rural area (Sour El Ghozlane) and sec ond is in an urban area (Rais Hamidou) and uses the wet process. To evaluate the atmospheric impacts generated by the cement factories, life cycle assessment approach is applied using Simparo 7.1 software and EDIP method. A comparative study of the impacts evaluated for the se processes and the contribution of the compound for all impact categories were determined
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    Etude cinétique et thermodynamique de l'adsorption des métaux lourds par l'utilisation des adsorbants naturels
    (2013) Aksas, Hammouche
    Cette étude a pour objectif d'étudier le potentiel d'utilisation de matériaux naturels (mélange homogène de noyaux de dattes et de grignons d'olives) issus de l'activité d'agriculture pour le traitement des eaux usées, chargées en polluant métallique : le chrome. Ces deux matériaux ont été activés chimiquement par l'acide phosphorique, en les mélangeant à différents pourcentages, afin d'obtenir une solution solide homogène et d'améliorer leur capacité adsorptive. Une caractérisation des adsorbants obtenus s'est avérée primordiale. Ainsi toute une gamme d'analyses physico-chimiques a été effectuée dont : la fluorescence X et la spectroscopie IRTF. L'adsorption des ions du chrome est étudiée en milieu dispersé (batch) et dynamique (colonne) à la fois sur les matériaux pur et à l'état du mélange à différentes proportions, composées d'une quantité fixe en noyaux de dattes fixe, et des quantités du grignon d'olive variées. Les résultats d'adsorption du chrome montre : qu'elle est maximale à un pH =5.6, croit avec la température et avec la concentration initiale du chrome dans la solution. Le modèle de Langmuir simule mieux les isothermes d'adsorption du chrome que d'autres modèles étudiés. Voyant l'hétérogénéité de l'adsorbant obtenu à partir du mélange de deux matériaux, le modèle de D-R est étudié et a donné une capacité d'adsorption considérable. Les paramètres thermodynami ques (ÀG, ÀH et ÀS ) ont été évalués de même que les paramètres cinétiques. La réaction d'adsorption du Cr suit incontestablement une loi cinétique d'ordre 2. Le processus d'adsorption semble cependant contrôler par la diffusion intra particulaire. Les essais de désorption ont démontré que les adsorbants (mélange du grignons d'olive et noyaux de dattes), peuvent être employés pour plusieurs cycles (trois) d'adsorption élution sans perdre leur capacité d'enlèvement du chrome. Les paramètres d'adsorption en colonne (débit d'alimentation, la hauteur du lit, concentration initiale..) et les systèmes mathématiques ont été étudié, et donnent des résultats assimilables à ceux obtenus expérimentalement. Finalement, il s'avère que l'adsorption du chrome, augmente ave c l'augmentation du taux du grignon d'olive dans le mélange d"adsorbant (grignon d'olive et noyau de date)
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    Etude de l'incinération des produits chromés de l'industrie du cuir de la Tannerie-Megisserie de Rouiba
    (2007) Aksas, Hammouche
    L’objectif initial de ce projet portant sur la valorisation des résidus de la tannerie pour en extraire le chrome.Ainsi par cette étude, nous visons toujours un double objectif : Contribuer d’abord à cerner puis réduire les problèmes de pollution de l’environnement liés aux rejets de la TAMEG de Rouiba. - Faire des essais de valorisation de ces résidus contenants du chrome. Notre projet s’est axe dans un premier temps sur l’extraction du chrome à partir des résidus d’incinération des déchets de la tannerie (boue, dérayure), par le protocole de Tessier et par lixiviation, ce dernier procédé permet de nous donner un aperçu sur le comportement des déchets cités ci-dessus à long terme. La récupération du Cr à partir des effluents, résidus et boue des rejets de la tannerie est dictée par des impératifs essentiellement d’ordre écologique et économique
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    Etude potentielle de mélange des adsorbants naturels (grignons d’olive et noyaux de dattes) pour l’adsorption du chrome
    (Aljest, 2016) Aksas, Hammouche; Cherifi-Nacy, H.; Babaci, N.; Louhab, K.
    Cette étude a pour objectif d’étudier le potentiel d’utilisation de matériaux naturels (mélange homogène de noyaux de dattes et de grignons d’olives) issus de l’activité d’agriculture pour le traitement des eaux usées, chargées en polluant métallique: le chrome. Ces deux matériaux ont été activés chimiquement par l’acide phosphorique, en les mélangeant à différents pourcentages, afin d’obtenir une solution solide homogène et d’améliorer leur capacité adsorptive. L’adsorption des ions du chrome est étudiée en milieu dispersé (batch) à la fois sur les matériaux pur et à l’état du mélange à différentes proportions, composées d’une quantité fixe en noyaux de dattes (ND), et des quantités du grignon d’olive (GO) variées. Les résultats d’adsorption du chrome montrent : qu’elle est maximale à un pH =5.6, croit avec la température et avec la concentration initiale du chrome dans la solution. Le modèle de Langmuir stimule mieux les isothermes d’adsorption du chrome que d’autres modèles étudiés (avec un coefficient de corrélation de 0.9988 pour (88% NDI, 12% GOI). L’adsorption du chrome augmente avec l’augmentation du taux du grignon d’olive dans le mélange d’adsorbant (grignon d’olive et noyau de date).
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    Optimization of a dermatological cream process formulation from Atractilys Gummifera L roots
    (Aljest, 2021) Larid, R.; Aksas, Hammouche; Touzouirt, S.; Hocine, I.; Kerbouche, R.; Abbadi, M.E.
    Atractilys Gummifera L or glue thistle,is one of the medicinal plants of the Mediterranean area. Belonging to the Asteraceae family, it is used in traditional medicine in various ways (maceration, decoction and fumigation). The rhizome of this plant is used as a healing agent in traditional Algerian medicine: it helps to heal burns. The aim of our work is to optimize the formulation process of a cream for dermatological application based on the roots of Atractilys Gummifera L, by using the methodology of experimental design. The physicochemical characterization of the underground part of this plant reveals a richness in organic substances (sugars 8.5%, lipids 2.29%, Brix degrees 33.34%), and mineral substances (ashes 4.21%). The study of the various parameters considered influential on the formulation process revealed that the optimal conditions for a more stable cream are: the solid (rhizome) / liquid (water) ratio 0.4 (m / V), the stirring time for 15 minutes and the stirring speed 500 rpm. The cream obtained has a rheofluidic (or pseudoplastic) behaviour, which can be described by the Casson model. This behaviour is suitable for a cream for dermatological application
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    Predictive optimization of electrical conductivity of polycarbonate composites at different concentrations of carbon nanotubes: A valorization of conductive nanocomposite theoretical models
    (MDPI, 2021) Sidi Salah, Lakhdar; Ouslimani, Nassira; Chouai, Mohamed; Danlée, Yann; Huynen, Isabelle; Aksas, Hammouche
    Polycarbonate—carbon nanotube (PC-CNT) conductive composites containing CNT concentration covering 0.25–4.5 wt.% were prepared by melt blending extrusion. The alternating current (AC) conductivity of the composites has been investigated. The percolation threshold of the PC-CNT composites was theoretically determined using the classical theory of percolation followed by numerical analysis, quantifying the conductivity of PC-CNT at the critical volume CNT concentration. Different theoretical models like Bueche, McCullough and Mamunya have been applied to predict the AC conductivity of the composites using a hyperparameter optimization method. Through multiple series of the hyperparameter optimization process, it was found that McCullough and Mamunya theoretical models for electrical conductivity fit remarkably with our experimental results; the degree of chain branching and the aspect ratio are estimated to be 0.91 and 167 according to these models. The development of a new model based on a modified Sohi model is in good agreement with our data, with a coefficient of determination R2 = 0.922 for an optimized design model. The conductivity is correlated to the electromagnetic absorption (EM) index showing a fine fit with Steffen–Boltzmann (SB) model, indicating the ultimate CNTs volume concentration for microwave absorption at the studied frequency range. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
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    The significant effect of K+ counterion in the enhancement of physicochemical and structural properties of amorphous aluminosilicates xerogels used as catalysts in the transesterification of waste frying oils
    (Taylor & Francis, 2023) Boufellah, Nassima; Aksas, Hammouche
    With the aim of better directing the polycondensation of oligomers during the synthesis of amorphous aluminosilicate xerogels by the sol-gel process using Na2SiO3, we reinforced the sols with Kþ counterion and studied its effect on the physicochemical and structural properties of the xerogels using XRD, FTIR, N2 physisorption, SEM, EDX, and TGA techniques as well as quantitative analysis of the acid sites by N-butylamine adsorption followed by potentiometric titration. Based on the results, the introduction of Kþ generated xerogels with good porosity and conferred resist- ance to matrix cracking. The amorphous character of the xerogels did not change after adding Kþ. FTIR spectra showed that the composition of the xerogels was improved after the addition of Kþ. Cation exchange and sulfur removal were much more efficient in the presence of Kþ which improved the acidity of the xerogels. The best percentages of Si and Al were observed at the Naþ/Kþ ratios of 4 and 1.The enhanced xerogel prepared with Naþ/Kþ ratio of 1 gave a biodiesel yield of 80.44% at the optimum parameters and was used for three reaction cycles without signifi- cant loss of biodiesel yield.
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    Support de cours gestion des risques industriels et sureté de fonctionnement des systèmes partie i
    (Université M'hamed Bougara de boumerdes : Département génie des procédés, 2021) Aksas, Hammouche
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    Treatment and modeling of industrial liquid effluent adsorption isotherm on plant-based materials
    (Aljest, 2021) Chaouadi, Hiba; Aksas, Hammouche
    Margins are not degradable due to the presence of substances (phenols, volatile fatty acids, etc.), which pose problems for the environment. In order to protect our environment, and currently know various treatment pathways such as adsorption, we studied the effects of diethylaminoethyl-cellulose (DEAE-ellulose) on the constituents of a gem and studied the adsorption power of DEAEcellulose of phenolic compounds present in the gills of Tadmait willaya Tizi-Ouzou. The latter showed that the best adsorption conditions are simple to achieve: temperature of 22°C, direct use of the margin (Vm = 10 ml, pH = 4.5) in rather large quantities compared to that of the adsorbent (mass ratio = 10) and that the Freundlich model better represents the adsorption of the phenolic compounds of the margin on the DEAE cellulose. Infrared spectroscopy analyzes showed the complex composition of the margin in various organic constituents. MEB- EDS microscopy analyzes revealed amorphous morphologies of the cellulose and the dry matter of the margin