Elaboration of inorganic microfiltration membranes with hydroxyapatite applied to the treatment of wastewater from sea product industry

This work describes the elaboration of a new ceramic asymmetric microfiltration membranes (active layers) based on synthesized lacunary hydroxyapatite (HA). The support, with tubular configuration, was prepared from cordierite. It has a highly uniform porous structure with large pores (7 μm). Rheology of HA slips, fixed the percentage of PVA addition, was studied in order to prepare a well-dispersed suspension suitable for slip casting process used to coat the active layer. After drying at room temperature for 24 h, the membrane was sintered at 600 °C. The characteristics of obtained membranes were: membrane thickness of about 32.5 μm; mean pores diameter of 0.5 μm and porosity of 48%. The obtained membrane was used to treat cuttlefish effluents generated from the conditioning seawater products industry. These industries consume a great amount of water. In Sfax (Tunisia), about 1000 m3/day are discharged in the littoral. Cross-flow microfiltration was carried out then, in order to reduce the turbidity and chemical oxygen demand (COD). The result showed a filtration flux of 125 l/h m2 and a high retention of turbidity (99%), colour and COD (92%).