Volume 11, No. 2 (2010)
Articles
AN INTERIM THERMODYNAMIC PROPERTY FORMULATION FOR SUPERCRITICAL n-HEXANE
SALAHEDDINE AZZOUZ(1), AICHA RIZI(2), ANISSA ACIDI(2), AZZEDINE ABBACI(2)*
Accurate information on the thermodynamic properties of supercritical fluids is highly sought for the chemical technology, especially, supercritical extraction technology. The thermodynamic properties of fluids near the critical region are strongly affected by the presence of fluctuations and therefore, can not be described by conventional equation. We have investigated an interim formulation for the behavior of the thermodynamic properties of n-hexane in the vicinity of the critical region. For this reason we have used the so-called “crossover model” to describe the thermodynamic properties of n-hexane in a wide range of temperatures and densities around the critical point.
VALORIZATION OF AN INDUSTRIAL WASTE RICH IN FERRIC CHLORIDE: APPLICATION IN THE TREATMENT OF INDUSTRIAL WASTEWATER <br/>VALORISATION D’UN REJET INDUSTRIEL RICHE EN CHLORURE FERRIQUE : APPLICATION AUX TRAITEMENTS DES EAUX RESIDUAIRES
ABDELKADER ANOUZLA*, SALAH SOUABI, MOHAMED SAFI, HICHAM RHBAL, YOUNES ABROUKI, ABDELHAK MAJOULI
Intense coloring due to the presence of the non biodegradable dyes, often toxic, in industrial wastewater, enormously poses problems of degradation of the receiving medium (i.e. surface waters). This study relates to the control of pollution of the industrial wastewater with physicochemical treatment by using an industrial waste rich in ferric chloride like original coagulant. This was tested for the control of pollution of the liquid effluents from the textile industry strongly polluted with organic matter. Several parameters were selected to control the purification of our effluents: turbidity, chemical oxygen demand (COD), and volume of sludge. The optimal concentration of the coagulant used in this treatment varies from one waste to another, according to the polluting load to treat. The output of this physicochemical treatment shows an important reduction of the polluting load of textile wastewaters: 91 – 87% of the organic matter and 84 – 85% of suspended solids, with less sludge production.
PHENYLPHOSPHONATO DERIVATIVES AND ADDUCT: SYNTHESIS AND SPECTROSCOPIC STUDIES
DINORA DE BARROS(1), LIBASSE DIOP(1)*, BERNARD MAHIEU(2)
Nine phenylphosphato derivatives and adduct have been synthesized and studied by infrared and Mössbauer techniques. The structures are polymeric, the oxoanion behaving as a bichelating, a tridentate, or a tetradentate ligand. The environment around the tin (IV) centre is octahedral or a trigonal bipyramidal.
SOME NEW SULFATO AND HYDROGENOSULFATO ADDUCTS: SYNTHESIS, INFRARED AND MÖSSBAUER STUDIES
WALY DIALLO(1), KOCHIKPA Y.A. OKIO(1), LIBASSE DIOP(1)*, LAMINE DIOP(2), UMBERTO RUSSO(3), ALAIN WATTIAUX(4)
Eight organotin (IV) (mainly sulfato) adducts have been synthesized and studied by spectroscopic methods. While considering the anionic component, the suggested structures are discrete; supramolecular architectures are obtained with secondary interactions through NH----Cl and NH----O hydrogen bonds while considering the cations, the anions behaving as monochelating, bridging or monocoordinating ligands, the environment around the tin (IV) centre being octahedral. Tetrahedral SnMe2Cl2 has been characterized spectroscopically.
NH3CH2CH2NH3PhCO2SnPhCl3OH, AN UNEXPECTED ADDUCT: SYNTHESIS AND SPECTROSCOPIC STUDIES
KOCHIKPA Y.A. OKIO, LIBASSE DIOP
On allowing NH3CH2CH2NH3(PhCO2)2 in slightly hydrated methanol to react with SnPh2Cl2, NH3CH2CH2NH3PhCO2SnPhCl3OH is obtained as a white precipitate. The IR and Mössbauer studies allow to suggest a moiety obtained by addition of OH- and PhCO2- to SnPhCl3, the environment around the tin being octahedral, PhCO2- behaving as a monocoordinating ligand.
DETERMINATION OF KINETICS OF DEGRADATION AND MOBILITY OF DITHIOCARBAMATES FUNGICIDES IN WATER AND IN MOROCCAN SOIL
Y. RIADI(1, 3), M. EL HADDAD(1, 2)*, R. MAMOUNI(1, 3)*, Y. RAMLI(4), M. AKSSIRA(5), T. FECHTALI(1), S. EL ANTRI(1), S. LAZAR(1)
Contribution analysis of dithiocarbamates pesticides used on tomatoes treatment has been reported. The study is focused on analysis and determination of some dithiocarbamates like, Maneb, Mancozeb, Zineb and Propineb, in order to achieve accurate impact of theses pesticides on water and soil. Analysis method is based on decomposition of dithiocarbamate by heating under acidic attack to give carbon disulfide complexed with copper acetate solution in presence of diethanolamine. Complex formed is dosed spectrophotometrically at 435 nm. Degradation kinetic of dithiocarbamate in aqueous media have been realized and proved that dithiocarbamate are degraded by simple air exposition. In the other hand, pH affects also dithiocarbamate degradation by increasing hydroxyl ions to participate for dithiocarbamate instability. Dithiocarbamate mobility on Moroccan soils samples have been realised and don’t have the same degradation mode.
NEW ORGANOTIN (IV) HETEROPOLYNUCLEAR COMPLEXES CONTAINING [SnPh2Cl2X]-(X = Cl, Br): SYNTHESIS AND SPECTROSCOPIC STUDIES
SEYDI MANSOUR SY SECK(1), LIBASSE DIOP(1)*, SAMUEL JOUEN(2), BÉATRICE HANNOYER(2)
Four [SnPh2Cl2X]-(X = Cl, Br) containing complexes with metal complexes adverse cations have been synthesized and studied by infrared and Mössbauer spectroscopy. The suggested structures are ionic, SnPh2Cl2X- as mononuclear, a binuclear or a trinuclear anion being in electrostatic interactions with the metal complex cation.
INFLUENCE OF SULFITATION ON THE DYNAMICS OF THE ACTIVITY OF OXIDIZING ENZYMES IN WHITE GRAPES
CARMEN POPESCU(1)*, ELENA POSTOLACHE(2), AUREL CIUBUCA(2), GABRIELA RAPEANU(3), TRAIAN HOPULELE(3)
Sulfur dioxide is used to control the browning of the wine, but it is known as an irritating agent of the digestive mucous membrane, of the lungs, and, at the same time, it destroys the thiamine, therefore the admissible quantities in vinification have been reduced. The research focused on the influence of different SO2 doses on the oxidizing enzymes found in grapes, in the must, and in the young wine. During the alcoholic fermentation the activity of the oxidizing enzymes dropped by 74.3 - 87.5% and the laccase was deactivated when doses of 50 - 75 mg.L-1 SO2 were used. The activity of the polyphenoloxidase (tyrosinase and laccase) gradually decreased during the alcoholic fermentation. Using the same doses of SO2, after the alcoholic fermentation, there has been noted a reduction of 56.6 - 71.8% of the activity of the peroxydase in wine compared to the first day of the alcoholic fermentation.
EFFICIENCY OF ULTRAFILTRATION CERAMIC MEMBRANES FOR TOXIC ELEMENTS REMOVAL FROM WASTEWATERS
N. SAFFAJ(1), R. MAMOUNI(2)*, A. LAKNIFLI(2), A. MOUNA(2), S. ALAMI YOUNSSI(3), A. ALBIZANE(3)
The preparation and characterization of porous ceramics multilayer ultrafiltration membrane is described. The first step consisted to prepare high-quality macroporous support in Moroccan clay. The choice of this material is based on its natural abundance and thermal stability. The microporous interlayer was then prepared by slip casting from zirconia commercial powders and finally the active UF toplayers was obtained by sol-gel route using ZnAl2O4 and TiO2 mixed sols. The performance of ultrafiltration membrane (TiO2 (50%) – ZnAl2O4 (50%)) was evaluated by pores diameter, water flux, thickness and molecular weight cut off (MWCO). The water permeability measured for this composite membrane is 9.42 L/(m2•h•bar), the thickness is less than 700 nm, the pore diameter is centered near 5 nm and the MWCO was about 4500 Da.
MATHEMATICAL MODELS FOR THE PREDICTION OF THE ENCAPSULATION BEHAVIOR IN FOOD SYSTEMS
IULIANA VINTILA*
The simulation of the encapsulation behavior in the multiphase complex system such food structure is based on the mathematical models constructed in respect with the Non-equilibrium thermodynamics Theory, Flory-Huggins Free Volume Theory (FHFV) and Complex Dispersed Systems (CDS). The present research paper presents the differential equations describing the evolution in time of the multiphase dividing surfaces and the excess quantities such as surface density, surface momentum, surface energy and surface entropy associated with the dividing surfaces. The new completed theory of bio-polymers phase transitions co-jointed from Interfacial Transport Phenomena (ITP), FHFV and CDS will be validated with the inverse analysis method.
KINETICS OF EDIBLE OILS PHYSICAL REFINING
IULIANA VINTILA*
Physical refining of edible oils is a valuable industrial processing which removes the minor compounds without chemical reagents involvement, based on the selective distillation process of the volatile compounds with high pressure steam at temperatures below 200 °C. Efficient removal of the minor compounds, which are considered as impurities in refined edible oils, is realized in the industrial practice both with the distillation and adsorption operation in the physical refining process. The paper presents the kinetics equation involved in a new optimization algorithm used to estimate the time-temperature dependency in the selective distillation process and adsorption kinetics equation.