Synthesis and characterization of coal fly ash based multipurpose ultrafiltration membrane

Abstract

In this work, coal fly ash was used as a major precursor to synthesize a multipurpose ceramic membrane by uniaxial compaction method. SEM, XRD and FTIR analysis were performed to identify the morphology, crystallinity and functional groups of the membrane. SEM image confirmed the porous structure and defect free membrane surface. XRD analysis revealed the existence of mullite, quartz and hematite crystalline phases. The minimum membrane sintering temperature was identified as 800 °C by Thermogravimetric analysis (TGA). The membrane porosity and average hydraulic pore radius were estimated as 39.8% and 41 nm, respectively. The membrane pure water flux increased from 2.09 to 11.31 m3/m2 sec while increasing the applied pressure from 69 to 483 kPa. A fixed concentration of Rhodamine B, Bovine Serum Albumin and Vanillin (50 mg/L) were tested with synthesized membrane to examine the separation performance at 207 kPa applied pressure. The separation efficiency of the ceramic membrane was in the order: Rhodamine B (95.2%) > Bovine Serum Albumin (92.8%) > Vanillin (39.4%). The results obtained in this study demonstrate that coal fly ash generated in thermal power plants could be effectively utilized to fabricate a multipurpose ultrafiltration membrane for different separation and purification applications in industries.