Optimization of phosphate/kaolinite microfiltration membrane using Box-Behnken design for treatment of industrial wastewater

The present work reports the preparation and characterization of flat ceramic membrane via dry pressing method made from natural phosphate as based material and kaolinite as additive to enhance membrane characteristics. Response surface methodology based on Box-Behnken design was used to optimize the preparation conditions notably amount of kaolinite (5-15 wt%), sintering temperature (900-1000 degrees C) and time of sintering (2-4 h). The optimized membrane has 40.2 MPa of flexural strength, 41.3% of porosity, 1045 L h(-1) m(2) bar(-1) of permeability and 0.35 mu m of average pore size. The phosphate/kaolinite membrane was subjected to the filtration of industrial textile wastewater and it showed excellent performance as microfiltration membrane. It is able to remove 98.99% of turbidity, 69.39% of total organic carbon, 74% of chemical oxygen demand and 77.11% of biological oxygen demand.