Preparation of Low-Cost Ceramic Membranes for Water Filtration: Valorization of Inorganic Clay Ores

Two samples of Algerian clay were collected for preparing ceramic membranes that can be used for water filtration. The membrane support was prepared from mountain clay from El Outaya mountains, Biskra province, Algeria, using calcium carbonate and methocel additive via extrusion method. The membrane was deposited using slip-casting method and the precursor slurry was based on polyvinyl aniline (PVA) and clay from Constantine mountains. The supports exhibited proportional evolution of mechanical resistance with sintering temperature, so the 1150°C support was selected for membrane deposition due to its porosity, which yielded optimal mean flux values (30 002.082, 21 559.54, and 16 511.71 L h^–1 m^–2 for 3 × 10⁴, 6 × 10⁴, and 9 × 10⁴ Pa pressure, respectively). The selected support possessed optimal permeability suitable for membrane deposition (factor k = 0.25679 L h^–1 m^–2 Pa^–1) because of necks and bridges formation made of mainly Gehlenite–Anorthite with some traces of Mullite. The cast membrane displayed low porosity and very high filtration performance since the Scanning electron microscope (SEM) image revealed a clean side section of the membrane with good homogeneity and low porosity rate. Moreover, the application of the cast membrane for filtration resulted in a very good filtration rate under high-pressure filtration when comparing the polluted water sample and the filtrate, showing the applicability of the designed membrane for microfiltration.