Waste environmental sources of metakaolin and corn cob ash for preparation and characterisation of green ceramic hollow fibre membrane (h-MCa) for oil-water separation

This study describes the preparation of green ceramic hollow fibre membranes derived from metakaolin (MK) and corn cob ash waste (CCA) as membrane support for water filtration and oil-water separation using phase inversion and sintering techniques. Pristine MK membrane is closely associated with its brittleness property and possesses low strength. In this study, a proportion of MK was substituted with corn cob ash (CCA), an agricultural waste by-product as pore forming agent material and sintering aid in preparing MK–corn cob ash hollow fibre membrane (h-MCa) for enhanced permeation and strength properties. MK:CCA ratio loadings at 35 wt % of powder were adjusted for fibres A-100:0, B-75:25, C-50:50, D-25:75, and E−0:100. The SEM image supported by EDSA revealed the high agglomeration of CCA–SiO2 particles coated with KCl, as the XRD analysis displayed mainly the crystal phases of KCl. The high content of CCA–KCl revealed its significant effect as body shaping and body forming in preform controlling the h-MCa suspension matrix structure. The viscosity of the suspension correlated with the dissolution of KCl in NMP suspension and MK–CCA fraction ratio to effectively function as a green enhancer and porogen towards the particle arrangement in the ceramic membrane matrix. The feasibility study showed that fibre B exhibited higher permeability (1359.93 L/m2h), oil/water removal efficiency (74.73%), and CCA maintained superior mechanical strength (41.61 MPa) at a significant low sintering temperature of 1200 °C, as the CCA possessed a great fluxing agent in the sintered membrane. Therefore, this study proved that green MK–CCA was effective, sustainable, and ecologically environmentally friendly for ceramic membrane support applications.