Fabrication of low-cost kaolinite/perlite membrane for microfiltration of dairy and textile wastewaters

This work is addressing the preparation of low-cost ceramic microfiltration membrane from cheap geomaterials namely kaolinite and perlite for the clarification of dairy and textile wastewaters. The effect of sintering temperature (950–1100 °C) and perlite content (25–75 wt%) on phase transformation, porosity, mechanical strength and permeability were investigated. The resulting membrane shows a good cohesion and a high flexural strength thanks to the heterogeneity of the microstructure of used geomaterials. The optimized kaolinite/perlite membrane containing 50 wt% of perlite sintered at 1050 °C exhibits a permeability of 1779 L h−1 m−2 bar−1 and an average pore diameter of 1.25 µm. More importantly, the clarification of dairy and textile wastewaters using kaolinite/perlite membrane could remove more than 97% of turbidity of both wastewaters, and reject 45% and 80% of total organic carbon respectively for dairy and textile wastewaters. In addition, the flux is mostly recovered after membrane cleaning and it reaches 90.17% and 75.23% for dairy and textile wastewater respectively. Besides, the cost of the prepared membranes was estimated to be 7.7 $ m−2 suggesting possible industrial scaling-up.