Synergistic catalytic filtration using Co-C/PVDF blending membrane activated by peroxymonosulfate: Fouling control and DOM transformation in real textile wastewater

Abstract

Ultrafiltration is widely employed for the advanced treatment of real textile wastewater; however, it encounters significant challenges of low separation efficiency and severe membrane fouling caused by residual organic matter (DOM) present in the conventionally treated biodegradable effluent. This study developed a blending membrane by incorporating cobalt-carbon (Co-C) nanocomposites, derived from ZIF-67, with polyvinylidene fluoride (PVDF) for synergistic filtration and peroxymonosulfate (PMS)-activated radical oxidation of real textile wastewater. The results indicate that an efficient removal of 62.9 % of total organic carbon-based DOM was achieved through online filtration-oxidation at a PMS concentration of 0.5 g/L, which is 3.7 times greater than the performance of pristine PVDF filtration. Furthermore, the system exhibited exceptional antifouling properties, evidenced by a flux recovery rate (FRR) of 71.2 % and a reduction in irreversible fouling ratio (R_ir=22.7 %), attributed to the in-situ oxidative degradation of foulants. Molecular-level analysis using three-dimensional fluorescence excitation-emission matrix and fourier transform ion cyclotron resonance mass spectrometry revealed that SO₄^•−/•OH radicals preferentially degraded aromatic DOM components. The membrane’s surface roughness reduction and loose foulant layer formation further alleviated fouling. This work provides a preliminary data for textile wastewater remediation and deepens the mechanistic understanding of catalytic membrane processes.