An indirect electrochemical process which is very efficient for the degradation of organic pollutants in aqueous solution, is described. The process, named electro-Fenton, is based on in situ electrochemical generation of Fenton's reagent (H2O2, Fe2+) which leads to the production of hydroxyl radicals °OH. Hydroxyl radicals are very powerful oxidizing agents. They react with organic pollutants and thus lead to their mineralization. In this study we have applied the electro-Fenton process to degrade an azo dye, the tartrazine, present in waste food industrial water. Degradation kinetics and chemical oxygen demand (COD) have been determinated. Here we show that the mineralization efficiency was around 80% for the tartrazine in case of a 0.05 mM aqueous solution at 5000 coulombs under our experimental conditions. The results display the efficiency of the electro-Fenton process to degrade organic matter present in water.
N. Bellakhal, M. Dachraoui, N. Oturan, M.A. Oturan
Electro-Fenton process, Hydroxyl radicals, Tartrazine, Degradation, Mineralization
The aim of this work is the ionic conductivity study of the two compounds β-LiMoO2AsO4 and Li(MoO2)2O(AsO4). The presence of the wide cavities in the first compound and the sites vacant in the interlayer space of the second compound allow considering that the cation Li+ can move through the network of these oxides. Indeed, our study shows that the compound β-LiMoO2AsO4 is a weak ionic conductor. On the other hand, the Li(MoO2)2O(AsO4) compound belongs to the class of the good ionic conductor.
M. Hajji, M.F. Zid
Lithium compound, Open framwork, Ionic conduction
The operation of absorption cycles involves at least two fluids: a solvent and a solution. Although other couples are studied, the only ones that are used in practice for almost all the applications are LiBr-H2O and NH3-H2O couples. These mixtures present some disadvantages such as pressure levels, corrosion, toxicity, high cost, as well as risk of crystallization for LiBr-H2O. The objective of this work is to analyze LiCl-MgCl2-H2O and LiCl-CaCl2-H2O mixtures. It consists of studying the effect of the various operating variables on the performance coefficient, the released power, the energy expenditure and the storage density both in heat pump and refrigeration modes. The obtained results show that LiCl-MgCl2-H2O presents interesting characteristics such as a coefficient of performance which can reach 1.95 in heat pump and 0.9 in refrigeration, a heat pump effect which can exceed by 100 % the LiBr-H2O one and a lower cost than this last. As for the storage density that translates the effective volume of the machine is favourable to the conventional mixture LiBr- H2O in heat pump and to LiCl-MgCl2-H2O mixture in refrigeration. Hence a technico-economic study is required in order to replace the LiBr-water system by one of the other two less expensive mixtures.
B. Chaouachi, S. Gabsi, A. Ben Brahim
absorption, heat pump, refrigeration, performance
The vanadium oxide VO2 (B), pure and well crystallized, was prepared by hydrothermal method (48 hours, 180°C and autogenous pressure). Diol hexane-1,6-diol HO-(CH2)6-OH has been used to reduce, in water, crystallized V2O5, in the molar ratio 1:1. The product VO2 (B) was characterized by powder X-ray diffraction, infrared spectroscopy, Paramagnetic Electronic Resonance, thermal analysis, Brunauer-Emmet-Teller technique and Scanning Electronic Microscopy.
N. Etteyeb, Z. Idoudi, N. Gharbi
hydrothermal synthesis, V2O5, hexane-1,6-diol, VO2 (B) crystallized
In order to study the effect of polymeric structure on drug release, different SCHIFF bases have been prepared by reaction of (m,p)-vinylbenzaldehyde with the following primary amines as organic models: aniline, benzylamine, 2-phenylethylamine, 3-phenylpropylamine, benzocaine and procaine. These SCHIFF bases have been copolymerized with N-2-vinylpyrrolidone (VP) in initial molar ratio of 4/96 (SCHIFF base: VP) using AIBN (5% in weight) as initiator in THF under nitrogen atmosphere. These obtained copolymers have been characterized and the incorporation ratios have been also calculated.
H. Merine, Z. Bengharez, L. Belarbi, A. Mesli
Active agent, SCHIFF base, copolymerization, incorporation ratio, glass transition temperature Tg, molecular weight
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