Abstract The purpose of this study was the development of a low-cost ceramic tubular membrane, using inexpensive materials, namely natural clay, and graphite as a porogenic agent. Such a low-cost membrane can be used as filters or porous supports for the preparation of multilayer ceramic membranes. Extrusion was used as a shape-forming method for this purpose. Graphite was selected as a porogenic additive. Raw materials were physicochemically and morphologically characterized. A comparative study of the influence of porogen content on membrane characteristics was carried out. Finally a graphite addition of 15 wt% and 850 °C as the sintering temperature were chosen. The obtained membrane had 41 vol% of porosity, diametral compression strength of 4 MPa, and relatively good corrosion resistance in basic and acid conditions. The performance of the membrane support was evaluated for diesel-in-water emulsion depuration as a function of pressure. Filtration test using 15% of porogen sample led to turbidity rejection factor of 95%. Therefore, it was considered that this membrane can be suitable for diesel/water emulsion treatment.

Resumo Este estudo concentrou-se no desenvolvimento e na preparação de membrana de microfiltração, com base em pó de argila natural da Tunísia de baixo custo, depositado em suporte cerâmico macroporoso. O depósito foi aplicado pela técnica de dip-coating, seguida de processo de secagem e sinterização a 700 °C. Os resultados revelaram que a membrana obtida foi caracterizada por boa adesão entre a camada da membrana e o suporte cerâmico, diâmetro médio de poros de 0,34 μm e porosidade de 39%. Esta membrana foi aplicada no tratamento de efluente gerado pela estação de tratamento de esgoto de Sfax, Tunísia. Os desempenhos em termos de fluxo e eficiência do permeado foram determinados para reduzir o teor de poluentes expresso em termos de turbidez, demanda bioquímica de oxigênio (DBO5) e matéria em suspensão (MES). Os resultados mostraram um valor de retenção de MES de cerca de 15% e turbidez e taxa de retenção de DBO de 99% e ~100%, respectivamente.

Abstract This study focused on the development and preparation of a microfiltration membrane, based on a low-cost natural Tunisian clay powder, deposited on macro-porous ceramic support. The deposit was made through a dip-coating technique, followed by a drying process and sintering at 700 °C. Results revealed that the obtained membrane was characterized by a good adhesion between the membrane layer and the ceramic support, an average pore diameter of 0.34 mm, and a porosity of 39%. This membrane was applied in the treatment of wastewater generated by the wastewater treatment plant of Sfax, Tunisia. The performances in terms of permeate flux and efficiency were determined in order to reduce the pollutant content expressed in terms of turbidity, biochemical oxygen demand (BOD5), and suspended matter (MES). Results showed an MES retention value of about 15%, and turbidity and BOD5 retention rate of 99% and ~100%, respectively.