Advancing water treatment sustainability: Investigating electrified Ti3C2Tx composite membranes for minimizing microplastic fouling.

ABSTRACT

The overuse of plastics has led to a large influx of microplastics (MPs) in water bodies and water/wastewater treatment plants. Coupled with the ongoing water crisis, this poses a threat to freshwater availability as MPs disrupt the operation of these plants. MPs cause severe fouling of low-pressure membrane technologies such as ultrafiltration (UF) due to the strong adhesion between MPs and the membrane surface. An electrified membrane-based technology is suggested as an alternative MP fouling mitigation strategy. In this study, composite membranes of sulfonated polyethersulfone (SPES)/MXene (Ti3C2Tx) were fabricated and evaluated as a promising candidate for mitigating fouling of MPs. The described SPES/Ti3C2Tx composite membrane was designed to improve important physiochemical properties such as conductivity without affecting water flux. The membranes were tested under different electrical potentials to find an optimal strategy to reduce MP fouling. The performance tests showed that the flux increased from 42 L m-2. h-1 at 0 V to 49 L m-2. h-1 at 2 V due to electrostatic repulsion when 5 wt% Ti3C2Tx was used as a result of the applied electric potential. In addition, it was shown that intermittent applied voltage using "30 min ON 60 min OFF" mode resulted in more stable water flux due to in-situ coagulant formation and cleaning. This study illustrates the potential of MXene-based membranes for mitigating MP fouling and paves the way for future research on membrane materials that can enhance system performance.