تحضير ودراسة الأغشية وحواملها انطلاقا من مواد خزفية

Abstract

In this work, the membranes supports have been prepared from local raw materials such as kaolin (DD2), kaolin (DD3) and calcium carbonates. These supports were made by extrusion technique in order to obtain tubular supports, the supports prepared from kaolin (DD2) and calcium carbonates have been sintered at 1250°C. It has been found that these supports had interesting characteristics; an average pore size of about 6.9 m, a porosity ratio around 53% and a flexural strength ≈36.62 MPa. Moreover, the pore size distribution is almost homogeneous (mono-modal type). These supports were selected to be substrates for the membrane layers used in microfiltration (MF).The membrane layers were elaborated from zirconium oxide, using slip casting technique. The specimens were subsequently sintered at 1150°C. The microstructure and porosity as well as the permeability have been also studied. It has been found that the average pore size is about 0.30 μm and a layer thickness ≈ 33 μm. These membranes are also used as supports for ultrafiltration (UF). The membrane layers of these later were also elaborated from zirconium oxide (ZrO2) with author diameters, using slip casting technique. The specimens were subsequently sintered at 700°C. The microstructure and porosity as well as the permeability have been also studied. It has been found that the average pore size is about 0.05 μm, a layer thickness ≈ 7 μm and the water permeability measured is about 407 l/h.m2.bar. However, the supports prepared from kaolin (DD3) and calcium carbonates were sintered at different temperature (1150-1300°C). It has been found that supports sintered at 1200°C had interesting characteristics; an average pore size is about 5 μm, a porosity ratio of 50.40%, a flexural strength ≈ 77 MPa and the pore size distribution is monomodal type. These supports were also selected to be substrates for the membrane layers of microfiltration (MF). The membrane layers of these later were elaborated from zinc oxide (ZnO), using slip casting technique. The specimens were subsequently sintered at 1000°C. The microstructure and porosity as well as the permeability have been also studied. It has been found that the average pore size is about 1.2 μm, a layer thickness ≈ 33 μm and the water permeability measured is about 880 l/h.m2.bar. A further important application in this work is waste and hard waters purification using membranes technique.