EFFICIENCY OF ULTRAFILTRATION CERAMIC MEMBRANES FOR TOXIC ELEMENTS REMOVAL FROM WASTEWATERS

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�20– 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

Nitrate removal from aqueous solutions by γ-Al2O3 ultrafiltration membranes

In the framework of understanding the transport mechanism that governs the filtration of NO3− solution through a γ-Al2O3 membrane with a nominal pore size of 5 nm at low ultrafiltration, a series of various types of nitrate solutions and operating conditions were investigated. The effect of filtration parameters such as pH, applied pressure and NO3− concentration on the selectivity and permeability of the membrane were studied using binary solutions (KNO3, NaNO3, Ca(NO3)2 and Mg(NO3)2) and ternary solutions ((NaNO3 + KNO3), (NaNO3 + Ca(NO3)2) and (Mg(NO3)2 + Ca(NO3)2). The experimental filtration results showed that high NO3− rejection was observed when pH was close to the point of zero charge of the membrane for both binary and ternary solutions. NO3− rejection increased with an increase of applied pressure. The rejection gradually decreased when the initial NO3− concentration increased. It appeared that the valency and hydrated radius of associated cation had a dramatic effect on NO3− rejection, with the divalent cations being more rejected than monovalent cations. In order to get to natural water complexity, three different samples of mineral water doped with NO3− from two different sources were studied at optimized operating conditions (25 ppm of NO3− and 6 bar). Experimental results demonstrated that NO3− rejection strongly depended upon the total mineralization and the presence of divalent anions in solution. In addition, the obtained results showed the potential use of γ-Al2O3 ultrafiltration membrane for denitrificatoin of contaminated water especially in Moroccan agricultural areas

Filtration of solution containing heavy metals and dyes by means of ultrafiltration membranes deposited on support made of Moroccan clay

International audienc

Elaboration and properties of TiO2–ZnAl2O4 ultrafiltration membranes deposited on cordierite support

International audienc