Silica porous membranes synthesis and characterization

International audienc

Purification of water effluent from a milk factory by ultrafiltration using algerian clay support

A milk factory sited at Boudouaou (40 km from Algiers) rejects a great quantity of effluent which contains soft whey. 8,000 1 are treated twice a week and are rejected into a river which supplies drinking water to the town population. Some analyses have shown an increase in the water acidity and both the BDO (biological demand of oxygen) and CDO (chemical demand of oxygen) attained 40,000 and 1,800 respectively. This is due to the presence of the lactose coupled with some organic matter. In this work, the purification of water is attempted by ultrafiltration using both gamma ahtmina and TiO2 membranes. Commercial mineral supports were used and their performance was compared to other supports elaborated from a natural Algerian clay (attapulgite). The results obtained have shown a good retention of lactose and total proteins giving rise to a pure water with a BDO of 90 and a DCO of 62. Moreover, the study of the influence of the pressure and the variation of the water flux has shown an improvement of the process through the use of the local clay support. Thus, this is appropriate for an economical and safe treatment of this water. Moreover, it combines a recovery of a valuable matter, which is the whe

Étude de la solution solide KTiOPO

Les poudres de KTiOP1-xAsxO4 (x = 0,25, 0,44 et 0,62) sont élaborées par voie sol - gel et les cristaux sont obtenus par la méthode de flux Les différentes structures de ces composés sont résolues, par isotypie avec la structure de KTiOPO4 jusqu’à des facteurs de reliabilité (R) de l’ordre de 0,04. La variation des paramètres de maille en fonction du taux de substitution a été déterminée. La répartition des atomes d’oxygène autour des atomes de titane a été corrélée avec la polarisation des liaisons Ti - O responsables des phénomènes de génération de seconde harmonique

Élaboration des composés KTiOPO

Le procédé sol - gel de destabilisation d’une solution colloïdale a été employé pour préparer les phosphate (KTP) et arséniate (KTA) de potassium et de titanyle. Ces matériaux piézoélectriques ont été caractérisés par analyse thermique, diffraction des rayons X, spectroscopie d’absorption infrarouge et génération de seconde harmonique (GSH). KIP et KTA cristallisent entre 500 et 600 °C et se décomposent entre 1150 et 1200 °C. Le rendement du signal de GSH de KTA est 1,65 fois celui du KTP

Characterisation of hydrophilic ceramic membranes modified by fluoroalkylsilanes into hydrophobic membranes

International audienc

Membrane Ozonation in Wastewater Treatment

The utilization of porous membranes in mass transfer processes of gaseous ozone to water was investigated. With this approach a direct control of the interface between gas and liquid is possible. Furthermore it prevents foam formation in the presence of surfactant pollution, which constitutes a problem in conventional ozonation methods. Different organic and inorganic membrane materials and geometrical arrangements were utilized and ozone transfer under varied experimental conditions was determined. Typical transfer rates obtained in the experiments were 10 g ozone per membrane square meter and hour, but under optimized conditions higher values were possible. A theoretical model was successfully applied to the results obtained. A peculiarity of the method is its inherent ozone dose control in relation to the volume flow of water