Waste-to-Resource Strategy To Fabricate Highly Porous Whisker-Structured Mullite Ceramic Membrane for Simulated Oil-in-Water Emulsion Wastewater Treatment

Industrial waste coal fly ash, containing hazardous metal oxides, poses potential threats to the environment and humans. Efficient recycling of such kind of solid state waste is highly desired yet still challenging. This work addressed waste-to-resource fabrication of a highly porous whisker-structured mullite ceramic membrane for separation of simulated oil-in-water emulsion wastewater by recycling of waste fly ash and natural bauxite with addition of WO3. The formation and characterizations of membranes were systematically studied including reaction mechanism, dynamic sintering behavior, open porosity, mechanical property, pore size distribution, microstructure, and pure water flux. The results show mullite formation temperature was decreased about 100 °C with addition of 20 wt % WO3, whereas open porosity significantly increased with WO3 content due to the formation of a highly porous interlocked whisker structure. Even without any pore formers, interestingly, the membrane with addition of 20 wt % WO3 ...