An innovative strategy for polyester microplastic fiber elimination from laundry wastewater via coupled separation and degradation using TiO2-based photocatalytic membrane reactor

Abstract

Microplastics (MPs) pollution, particularly from polyester microplastic fibers (PMPF) released during laundry processes, has become a significant environmental issue. This study explores an effective solution for rejecting and degrading both simulated and real PMPF in laundry wastewater using a TiO2-based photocatalytic membrane reactor (PMR). The immobilized-PMR integrates an Ag-decorated TiO2 (Ag- TiO2) catalyst onto an Al2O3 ceramic membrane, combining the photocatalytic capabilities of TiO2 with the enhanced efficiency provided by silver nanoparticles’ plasmonic effect. This setup aims to optimize PMPF degradation under ultraviolet-C (UVC) light irradiation. The performance of the immobilized-PMR was assessed with simulated and real laundry wastewater containing PMPF. Results showed that the Ag- TiO2 catalytic membrane achieved up to 99.9 % rejection of both simulated and real PMPF, and a 23.2 % degradation rate of simulated PMPF after 48 h of UVC irradiation. Detailed morphological analyses via FESEM and chemical characterization through FTIR and GC/MS confirmed substantial degradation of polyester fibers. This study demonstrates the potential of the TiO2-based immobilized-PMR as a scalable, efficient solution for mitigating fibrous MP pollution in wastewater. The approach combines photocatalytic degradation with membrane filtration, effectively rejecting and degrading fibrous MPs, thereby reducing their environmental impact.