Génie Chimique

Nombre total de résultats : 48
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STUDY OF THE MODIFICATION OF THE DIATOMITE SURFACE BY CHEMICAL ACTIVATION FOR A PRACTICAL APPLICATION

A. BALASKA, H. MERADI, A. HAMOUDA, T. CHOUCHANE, R. AYACHE, M. SELAMETTE, M-H. SAMAR, L. ATOUI  (2010)
Article de conférence

The diagrams of X for the natural and modified diatomite show remarkable modification onthe surface of this material, we were tested the modified diatomite for filtration of water,using adsorption process.The adsorption isotherm on diatomite was studied using UV Spectrophotometry, the surfaceof diatomite was modified with Sulphuric acid by using chemical activation method, and thetrapping behavior of the modified diatomite for phenol was investigated.The influence of some parameters such as the pH of the medium and the initial concentrationof the pollutant on the process of adsorption was also evaluated.Diatomite and modified diatomite are effective adsorbents for removal of phenol fromsolution at pH 5.It was shown in the present investigation that the treatment of diatomite by sulphuric acidimproves its performance as adsorbent for phenol and, when the adsorption capacity wasincreased after chemical treatment.The experiment results show that adsorption isotherm fits in Freundlich equation. Voir les détails

Mots clés : Surface modification, material, diatomite, Environnement, pollution

Effet de la composition chimique et la morphologie d’un matériau d’isolation thermique sur le pouvoir d’isolation

A. BALASKA, H. MERADI, Y. LAIB LEKSIR, M. ABBESSI, M-H. SAMAR  (2008)
Article de conférence

Dans cette étude, l’influence de la composition chimique de la diatomite, qui est un matériau d’isolation thermique utilisé dans les aciéries en différentes granulométries sur le pouvoir d’isolation a été étudié. Les effets des paramètres tels que la porosité et la composition chimique et l’étude thermique par DSC sur les propriétés physiques et mécaniques du matériau ont été étudiés.Le protocole expérimental est basé sur l’ajout d’une quantité du sable à la diatomite brute en plusieurs rapports. Les échantillons du produit fini ont été analysés par la méthode de FRX florescence afin d’identifier l’influence du sable sur le comportement de la diatomite et la morphologie du produit par la mesure de la porosité des produits obtenus, dont la teneur en silice augmente de 70% jusqu’au 90% en fonction de la quantité du sable ajoutée et la porosité a diminuée. D’autre part, l’analyse thermique, la densité apparente sont utilisées pour explique l’influence de l’ajout du sable sur le transfert thermique donc, la résistance du produit fini et l’étalement du produit sur la surface à isoler pour la densité apparente.Les matériaux avec des rapports optimaux ont la meilleure résistance à la haute température et l'isolation thermique dans toute la série de travail, en raison de la basse conductivité thermique, dont le produit léger peut être employé pour montrer l'isolement élevé dans la structure. Voir les détails

Mots clés : diatomite, isolation thermique, porosité, analyse minéralogique

STUDY OF THE ELIMINATION OF PHENOL BY ADSORPTION ON AN ALGERIAN DIATOMITE

A. BALASKA, H. MERADI, R. AYACHE, M. SELAMETTE, M-H. SAMAR, L. ATOUI, M. ABBASSI  (2010)
Article de conférence

The phenol and its derivatives are compounds which are found in several types of industrial wastewater such as: rejections of painting, paper, plastics, oil and gasoline, steel, the textile, pharmaceutical industry and the wood industry. They are toxic for the man and for and the other aquatic environments; of which, a small concentration of phenol in the medium (2.5 mg/l) causes an unpleasant odor of drinking water.In this study, we used the diatomite of the deposit of Sig (west of Algeria) like an adsorbent to eliminate this type of organic pollution. The several techniques were used to characterize this material and explain the morphology and the composition of this powder. The porous structure of the raw diatomite is clearly observed in the MEB, the diffraction of X-rays presents more than 80% of amorphous state and the analysis by FRX shows that the powder contains more than silica 65 %. The adsorption of phenol was carried out on the raw diatomite and modified by chemical activation; we were used the sulphuric acid 5 mol/l.The kinetics and the isotherms of adsorption were established for the two adsorbents. The influence of some parameters such as the pH of the medium and the initial concentration of the pollutant on the process of adsorption was also evaluated. Voir les détails

Mots clés : Phenol, diatomite, characterization, adsorption

Nanostructured CuO directly grown on copper electrochemically: synthesis and characterization

A.HAMAM, M.Mokhtari, D.OUKIL, S.Bouhouche, L.MAKHLOUFI  (2015)
Article de conférence

Nanostructured CuO was directly grown on copper foam. The Cu foil was modified electrochemically by Cyclic voltammetry (CVs) a three electrode cell with Cu foam working electrode, platinum foil counter electrode and saturated calomel reference electrode in 5 M KOH solution,after reaction for Cu electrooxidation at room temperature. The shiny Cu foil surface turned to complete black after the reaction. The obtained electrode (denoted as CuO/Cu). The morphology and structure of the CuO were examined by X-ray diffraction spectroscopy. Voir les détails

Mots clés : Copper substrate, cyclic voltammetry

PREPARATION DE NANO-COMPOSITES A MATRICE POLYMERE CDTE EN VUE D’PPLICATIONS DANS LE PHOTOVOLTAIQUE

Ait Atmane Abdenour, Chellouche Azeddine, Hamam Abderrazak  (2014)
Article de conférence

Dans ce travail, nous avons élaboré des nanocompsites DdTe-PMMA (film et pastille),Cdte-PS (film et pastille).Les résultats de la caractérisation par diffraction des rayons X sur les nanocomposites étudiés ont montré l’incorporation des nanocristallites de CDTe dans les deux matrices.Les analyses par spectrométrie Raman et par spectroscopie infrarouge à transformée de Fourier des nanocomposites préparés ont révélé l’existence des modes propres de CdTe. La caractérisation par transmission optique dans la gamme UV-Vis-proche infrarouge amontré que l’incorporation des cristallites de CdTe diminue la transmission et élargit la gamme de transparence des matrices hotes.le spectre de la photoluminescence d’une pastille de CdTe-PS a montré une émission intense et étroite mettant en évidence l’élargissement du gap optique du nanocomposite et a confirmé l’effet du confinement quantique. Voir les détails

Mots clés : Nano-composites, matrices polymère, films, PMMA, PS, CdTe.

Phenol photodegradation process assisted with Wells–Dawson heteropolyacids

Adel BALASKA, Mohamed Elhadi Samar, Azzeddine GRID  (2015)
Publication

This work aims to investigate the catalytic properties of the heteropolyacids (HPAs) withinphotocatalytic process. Photocatalytic degradation of phenol in aqueous solution was performedusing Wells–Dawson HPAs as catalysts under UV-illuminated condition at 254 nm.The effects of various parameters such as, concentration of catalyst, initial pH, and initialphenol concentration on the performance of photocatalytic process have been investigatedto obtain the efficient and durable catalysts and determine the better reaction conditions.The kinetics and the efficiency of phenol degradation were determined by various analyticaltechniques, such as HPLC and TOC. The results show that the photocatalytic degradationefficiency increases with decreasing pH and the optimum pH is 2 for both catalysts. Thephotodegradation follows pseudo-first-order kinetics with rate constants k = 8.56 × 10−2 and 9.94 × 10−2 min−1 for iron- and vanadium-substituted HPAs, respectively. Voir les détails

Mots clés : Well-Dawson HPA, Homogeneous catalysis, Phenol photodegradation, UV irradiation

Pillared clays as catalysts for methyl parathion removal by advanced oxidation processes

Salim Kouraichi, Mohamed El-Hadi SAMAR, Mostefa ABBESSI, Hassane BOUDOUH, Adel BALASKA  (2015)
Publication

A natural bentonite from Mostaganem in Algeria was modified by intercalation with polyoxocationic solutions (Al•Fe, Al•Co, Al•Cu, Al•Fe•Cu or Al•Fe•La). The modification of the bentonite occurred via pillaring by ionic exchange with these solutions. The addition of these solutions led to the formation of pillared clays with important catalytic properties in environmental impact reactions. The structural and textural properties of materials calcined at 500 °C were determined by several techniques: X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and N2 adsorption–desorption analysis. The pillared clays were then used as a Fenton-type heterogeneous catalyst for the heterogeneous sono-Fenton process for the oxidation of methyl parathion in water. The catalytic tests revealed the activity of the introduced iron species and the promoter effect of lanthanide or copper on the catalytic activity of these species. The sono-Fenton method showed promising results for the degradation of methyl parathion when compared with the Fenton method. Therefore, the sono-Fenton method can be a viable alternative technology to the existing methods for treating methyl parathion in wastewater. Voir les détails

Mots clés : Advanced oxidation process, Pillared clay, Sono-Fenton, Methyl parathion pesticide, Wastewater treatment

Phenol photodegradation process assisted with Wells- Dawson heteropolyacids

Adel BALASKA, Mohamed Elhadi Samar, Azzeddine GRID  (2015)
Publication

This work aims to investigate the catalytic properties of the heteropolyacids (HPAs) within photocatlytic process. Photocatalytic degradation of phenol in aqueous solution was performed using Wells-Dawson HPAs as catalysts under UV-illuminated condition at 254 nm. The effects of various parameters such as, concentration of catalyst, initial pH and initial phenol concentration on the performance of photocatalytic process have been investigated to obtain the efficient and durable catalysts and determine the better reaction conditions. The kinetics and the efficiency of phenol degradation were determined by various analytical techniques, such as HPLC and TOC. The results show that the photocatalytic degradation efficiency increases with decreasing pH and the optimum pH is 2 for both catalysts. The photodegradation follows pseudo first-order kinetics with rate constants k = 8.56×10−2 min-1 and 9.94x10-2 min-1 for iron and vanadium substituted - HPAs, respectively. Voir les détails

Mots clés : Wells-Dawson HPA, Homogeneous catalysis, Phenol photodegradation, UV irradiation

Pillared clays as catalysts for methyl parathion removal by advanced oxidation processes

Salim Kouraichi Mohamed El-Hadi Samar, Mostefa ABBESSI, Hassane BOUDOUH, Adel BALASKA  (2015)
Publication

A natural bentonite from Mostaganem in Algeria was modified by intercalation with polyoxocationic solutions (Al•Fe, Al•Co, Al•Cu, Al•Fe•Cu or Al•Fe•La). The modification of the bentonite occurred via pillaring by ionic exchange with these solutions. The addition of these solutions led to the formation of pillared clays with important catalytic properties in environmental impact reactions. The structural and textural properties of materials calcined at 500 °C were determined by several techniques: X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and N2 adsorption–desorption analysis. The pillared clays were then used as a Fenton-type heterogeneous catalyst for the heterogeneous sono-Fenton process for the oxidation of methyl parathion in water. The catalytic tests revealed the activity of the introduced iron species and the promoter effect of lanthanide or copper on the catalytic activity of these species. The sono-Fenton method showed promising results for the degradation of methyl parathion when compared with the Fenton method. Therefore, the sono-Fenton method can be a viable alternative technology to the existing methods for treating methyl parathion in wastewater. Voir les détails

Mots clés : Advanced oxidatio process, Sono-Fenton, heterogeneous catalysis, Methyl parathion pesticide, Wastewater treatment

Elimination du plomb en solution par la sciure de bois

Toufik CHOUCHANE, Saliha Chouchane, Atman Boukarai, Adel BALASKA, Mohamed Elhadi Samar  (2011)
Publication

Cette étude présente les résultats obtenus lors de l’utilisation de la sciure debois pour l’élimination du plomb contenu dans les eaux usées. Les propriétés de sorptionont été déterminées en régime discontinu. Les résultats des essais montrent qu’un grammede sciure de bois activé peut fixer 40,04 mg/g de plomb selon le modèle de Langmuir, 1erversion, avec une cinétique du pseudo premier ordre, où le temps d’équilibre est de 10minutes. Les mesures réalisées révèlent aussi, que la diffusion externe contrôle la vitessedu processus globale de la sorption. La diffusion dans les pores ne présente pas l’uniquemécanisme réactionnel limitant cette cinétique, ce mécanisme est basé aussi sur l’échangecationique, où les ions de bases jouent un rôle très important. En dernier, on montre quecette sorption est spontanée (ΔG < 0) jusqu'à 40 °C, exothermique (ΔH < 0) et aucunchangement n’a été effectué au niveau de la structure de la sciure de bois (ΔS < 0). Voir les détails

Mots clés : Plomb Sportion, Sciure de bois, eau, pollution