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 mum). 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 degreesC. The characteristics of obtained membranes were: membrane thickness of about 32.5 mum; mean pores diameter of 0.5 mum 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 m(3)/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 1251/h m(3) and a high retention of turbidity (99%), colour and COD (92%). (C) 2004 Elsevier B.V. All rights reserved.