Arash Khosravi

In this research, inexpensive materials including kaolin, natural zeolite, and fly ash, as well as alpha alumina for comparison, were used to fabricate ceramic membranes for the treatment of greywater. 11 tubular membranes with a length of 25 centimeters, an inner diameter of 10 millimeters, and an outer diameter of 14 millimeters were fabricated with different percentage compositions using the extrusion method. Two samples of mullite-natural zeolite-fly ash membrane (15-10-75) and mullite-alpha alumina-fly ash membrane (80-10-10), which demonstrated the best performance, were selected as the optimal membranes. Different characterization tests, including porosity, mean pore size, scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and mechanical strength, were conducted. The highest permeation flux equals 632 (L/m2.h) and corresponds to the mullite-natural zeolite-fly ash membrane (75-10-15). The highest removal efficiency compared to the mullite-natural zeolite-fly ash membrane (75-10-15) is related to the mullite-alpha alumina-fly ash membrane (80-10-10). The removal efficiencies for COD, BOD, detergent, TSS, sulfate, nitrate, phosphate, and turbidity in the mullite-alpha alumina-fly ash membrane (80-10-10) are 91.5%, 89.75%, 74.66%, 98.88%, 64.6%, 32.35%, 94.67%, and 95.87%, respectively. The highest flexural strength belongs to the mullite-natural zeolite-fly ash membrane (15-10-75), equal to 30.903 MPa. The porosities for the mullite-natural zeolite-fly ash membrane (75-10-15) and the mullite-alpha alumina-fly ash membrane (80-10-10) were found to be 33.1% and 41.18%, respectively.