BIOSORPTION OF METHYLENE BLUE FROM WASTE WATER USING LEBANESE CYMBOPOGON CITRATUS (CITRONNELLE)

The objective of this study was to investigate the possibility of using Lebanese Cymbopogon citratus stem as an alternative adsorbent for the removal of methylene blue from aqueous solutions. Different parameters such as the effect of initial concentration, pH, adsorbent dose, contact time and temperature were studied. Maximum adsorption capacity (61%) of MB was obtained at PH=6 an initial concentration 200 mg/L after 24h and at 25 ˚C. The adsorption isotherm was better described by a Freundlich model rather than a Langmiur model. Based on these results, it can be concluded that the stems of Cymbopogon citratus is effective as an alternative adsorbent for MB remediation in waste water

BIOSORPTION OF METHYLENE BLUE FROM WASTE WATER USING LEBANESE CYMBOPOGON CITRATUS (CITRONNELLE)

The objective of this study was to investigate the possibility of using Lebanese Cymbopogon citratus stem as an alternative adsorbent for the removal of methylene blue from aqueous solutions. Different parameters such as the effect of initial concentration, pH, adsorbent dose, contact time and temperature were studied. Maximum adsorption capacity (61%) of MB was obtained at PH=6 an initial concentration 200 mg/L after 24h and at 25 ˚C. The adsorption isotherm was better described by a Freundlich model rather than a Langmiur model. Based on these results, it can be concluded that the stems of Cymbopogon citratus is effective as an alternative adsorbent for MB remediation in waste water

Metal concentrations in river water and bed sediments of the Lower Litani River Bassin, Lebanon

The distribution of pollutants in the Litani River is almost severe. It resulted from domestic, sewage, agricultural and industrial sources. In this study, the distribution of metals (Cu, Fe, Cd, Mg, Zn, Pb , Al, Ba, Ni, Mn, Ag and Cr) were measured in river water and the bed sediments of the Lower Litani River Basin (LLRB). The impacts of metals on the water quality were monitored during the rainy, mid rainy and dry season in the year 2012. The objectives of this study were first to identify possible sources of metals (i.e. geological and/or anthropogenic) and then to characterize the chemical behavior of these metals in water and bed sediments. Water and bed load sediments were sampled at six sites along the LLRB main watercourse, The metal concentrations in the river sediments were remarkably high, but varied between different sampling sites, and the concentrations in water were mainly within the permissible limits. The metal contents in bed sediment were highest during closure of summer period. By applying the principal component analysis applied to total and extractable metal contents as a tool for studying metal pollution in the LLRB, it was useful to distinguish between anthropogenic and natural sources

Physiochemical and Microbial Assessment of Water Quality in the Upper Litani River Basin, Lebanon

Water resources in Lebanon are witnessing serious challenges and reached depletion. One of the major challenges is the quality deterioration, which is accompanied with uncontrolled resources management, and thus the increasing demand. There are several consumption aspects, mainly the domestic, industrial and irrigation. Yet, exploitation of water resources in Lebanon implies both the surface and groundwater. However, surface water resources are most used due to the ease of exploitation processes, and more certainly water from rivers. Typically, the Litani River is the largest one in Lebanon. The river has been lately subjected to several aspects of deterioration in its quality. This includes the major physiochemical characteristics. This study aims to assess the seasonal variations in water quality in the Upper Litani River Basin, including the Qaraaoun Lake. Samples were collected from particular sites along the river, and at several dates during the years of 2010 and 2011. The carried analysis implies the physical (pH, T°, TDS, Ec), chemicals (Na+, Ca2+, Mg2+, Cl?, SO42?, NH3+, NO3?, PO42?, K+, BOD5 and COD, Heavy metals (Fe, Ni, Zn, Cu, Cr, Al, Ba, Pb, Mn) and microbiological parameters. This resulted numeric data are being compared with WHO guidelines. In addition, PCA was applied to evaluate the data accuracy. We can conclude that the variables used are very efficient and the dry season shows the worst water quality with nitrate, metal and microbial enrichments. Keywords: Water Contamination, Human Interference, Litani River, Principal Component Analysis

Synthesis by ATRP of Polystyrene-b-Poly(4-vinylpyridine) and Characterization by Inverse Gas Chromatography

A linear diblock copolymer [Polystyrene-b-Poly(4-vinyl-pyridine)] (PS-b-P4VP) was successfully prepared through Atom Transfer Radical Polymerization (ATRP). This synthesis is performed in two successive steps: using the (1-bromoethyl) benzene as initiatorand and Hexamethyl tris [2(dimethylamino)ethyl] amine as ligands in a protic solvent. The first step of the synthesis allows the realization of block polystyrene having a terminal function; however, Bromine (Br) permits the grafting of the second successive block P4VP. RMN -1H demonstrates that the P4VP block has been grafted onto the PS block. The molecular weight of PS-b-P4VP is determined by size exclusion chromatography, and its thermal stability is examined by TGA. The surface and the thermodynamic properties of this copolymer are studied by inverse gas chromatography (IGC). The new Hamieh Model shows that the synthesized copolymer PS-P4VP has an amphoteric behavior with rather very basic character that is six times stronger than acidic character (in Lewis terms), reflected the presence of acidic and basic groups in the structure of the PS-P4VP copolymer, more particularly the presence of benzenic, methyl and vinylpyridine groups

Synthesis of mono- and bi-layer zeolite films on alumina substrates

AbstractBilayer zeolite films ZSM-5/ZSM-5, ZSM-5/EMC-1 and NaY/ZSM-5 were synthesized on α-alumina plates. The bottom ZSM-5 or faujasite Y (NaY) zeolite layers were obtained by direct hydrothermal synthesis or by using a seeding step followed by a secondary growth method, respectively, while the secondary growth method was used for the synthesis of all the top zeolite layers. A complete characterization of the obtained materials is proposed using various techniques, such as X-ray diffraction, scanning electron microscopy, X-ray fluorescence and nitrogen sorption measurements. Continuous and highly crystallized bi-layer zeolite films with thicknesses around 11–18 μm were obtained

High Quality Bio-Oil Obtained from Catalyzed Pyrolysis of Olive Mill Solid Wastes in a Bi-Functional Reactor

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Control of Spatial Organization of Gold Nanoparticles Using Cylindrical Nanopores of Block Copolymers Films

Abstract In this paper, a sequential process of elaboration of hybrid nanostructured composite films has been proposed. The combination of phase separation in poly(styrene-block-4vinylpyridine) (PS-P4VP) block copolymer leading to the formation of nanopores, and gold nanocolloids synthesis confined in the nanoholes has allowed the facile fabrication of hexagonally arranged gold nanoparticles (NPs) onto silicon wafer. In particular, the nucleation and growth of gold nanoparticles took place within the nanopores, where they are confined in both size and shape the formed Au NPs. The resulting hybrid nanoscomposite has been characterized by Atomic Force Microscopy (AFM) and X-Ray Spectroscopy (XPS). This facile and simple process represents an opened pathway to several technologically important materials fabrication such as hierarchical and ordered crystal architectures. Indeed, the approach based on solvent phase, which is particularly attractive due to its low energy requirement, and the safety and environmentally gentle processing conditions

Incorporation par synthèse directe d'anions tungstophosphates dans des silices mésoporeuses organisées et étude de leurs propriétés catalytiques

Ce travail concerne la préparation et la caractérisation de catalyseurs obtenus par incorporation de H3PW12O40 (PW) dans la paroi de la silice mésoporeuse au moment de la polycondensation. Dans ce but, deux stratégies de synthèse ont été envisagées. Vu l'instabilité de PW à pH élevé, les préparations ont d'abord été effectuées dans un domaine de pH compris entre 4 et 6. La polycondensation de la silice, issue de l'hydrolyse d'alkoxysdane, peut ainsi être contrôlée en présence d'un tensioactif neutre (Triton TXIOO). Un tensioactif canonique, C16TMABr, a été ajouté afin de créer des interactions fortes avec les anions PW. Une deuxième série de synthèses, utilise un milieu plus acide, en présence ou non d'anions F- cormne catalyseur de condensation de la silice. Différents systèmes Parcellaires mixtes ou neutres ont été étudiés: TXIOO/CI6 , P123/CI6 , Tergitol 15S-12 et Tween 60. Généralement les phases obtenues montrent un seul pic de diffraction, caractéristique des solides de type MSU. Le système micellaire P123/C 16TMA+ à faible teneur en PW, conduit à un solide de type SBA-15 présentant une excellente organisation dans la périodicité des canaux. Les -caractéristiques poreuses ont été déterminées par adsorption d'azote. La présence de PW après incorporation est caractérisée par un signal spécifique en RMS MAS du 31P. Les mesures de temps de relaxation sur ces solides montrent une faible mobilité des espèces PW incorporées par rapport à celles imprégnées. Dans l'époxydation du cyclohexène en présence de H202, les produits majeurs formés sont l'époxycyclohexane, le cis et le trans-1,2-cyclohexanediol. La conversion du cyclohexène augmente avec le taux de PW introduit. L'étude cinétique avec divers catalyseurs, indique que la sélectivité en époxyde augmente alors que celle en diols diminue. Un comportement comparable en terme de sélectivité envers le cis-1,2-cyclohexanediol est obtenu pour PW pur et imprégné, alors que PW incorporé est plus sélectif pour l'isomère transMULHOUSE-SCD Sciences (682242102) / SudocSudocFranceF

Study of genetic mutations and dynamic spread of SARS-CoV-2 pandemic and prediction of its evolution according to the SIR model

In this work, we aim to study that the dynamics behavior for cumulative number of SARS-CoV-2 pandemic can provide information on the overall behavior of the spread over daily time.The cumulative data can be synthesized in an empirical form obtained from a Susceptible-Infected-Recovered (SIR) model previously studied on a Euclidean network. From the study we carried out, we can conclude that the SIR model on the Euclidean network can reproduce data from several countries with a deviation of precision for given parameter values. This gives an insight into the different agents that influence the behavior of SARS-CoV-2 especially during the virus mutation period. We are thus trying to analyze the effect of genetic mutations in different countries, and how a specific mutation can make the virus more contagious