TiO2-embedded dual-layer mullite hollow fiber membranes for efficient removal of Persistent organic pollutants from wastewater

Abstract

Persistent organic pollutants (POPs) are toxic pollutants that harm the environment and ecosystems. This study presents a novel approach to develop a dual-layer hollow fiber ceramic membrane for phenolic compound removal. A co-extrusion-based phase inversion process and co-sintering techniques were employed to fabricate the membrane, and the effects of TiO2 loadings on the outer layer were investigated. Characterization techniques, including FTIR, SEM, EDX, and zeta potential analysis, were used to analyze the mullite and TiO2 powders and membranes. The membrane’s performance was evaluated through rejection tests of POPs at various concentrations (10, 500, and 1000 ppm) and fouling assessments were conducted. The results showed that the M−MT0.6 membrane, with a mean pore size of 0.0245 μm, effectively rejected benzoic acid (81.45 %), gallic acid (91.45 %), and hydroquinone (74.49 %) from wastewater, achieving the highest permeate flux (1320.50 L/m2·h) for gallic acid at 10 ppm. Additionally, M−MT0.6 exhibited minimal fouling over a 1-h filtration cycle, with the lowest fouling rate (35.1 %) recorded at 1000 ppm for BA, attributed to effective backwashing. However, higher fouling rates were observed at 10 ppm for BA (90.10 %) and HQ (83.50 %). Overall, this study demonstrates the potential of the novel membrane for effective removal of POPs from industrialwastewater.