فهرست نشریات علمی دسترسی آزاد ایران

Eggshell waste, a common by-product of the food industry, creates both environmental and disposal concerns. In this study, we examine how eggshell powder can serve as an environmentally friendly pore-forming agent in the gel-casting production of α-Al2O3 ceramic membranes, to improve membrane performance while giving new value to this biowaste. Eggshell powders with particle sizes of 2 µm, 4 µm, and 10 µm (5 wt. %) were incorporated into α-Al2O3 (95 wt. %) and compared with pure α-Al2O3 membranes. Membranes were sintered at 1250 °C, 1350 °C, and 1450 °C, and characterized for porosity, shrinkage, mechanical strength, and water flux. The addition of eggshell powder increased porosity from 43% (pure α-Al2O3) to 57.23% (10 µm, 1450 °C) and reduced linear shrinkage by up to 50%. Mechanical strength improved with smaller particle sizes, reaching 4.94 MPa for 2 µm particles at 1450 °C, compared with 3.43 MPa for pure α-Al2O3. The membranes containing 10 µm eggshell particles showed a marked increase in water flux, reaching 1860 LMH at 1450 °C compared with 1250 LMH for the pure α-Al2O3 sample. This result shows that adding eggshell powder can improve membrane performance while offering a practical, sustainable way to reuse biowaste in ceramic production, transforming a waste problem into a practical technological solution.