Ferrocene-functionalized ultrafiltration membrane: Integrated approach for natural organic matter separation and catalytic degradation of small-molecule dye

Water pollution and scarcity have become major global challenges. The Fenton oxidation method has been widely applied in organic wastewater treatment due to its ability to efficiently degrade toxic organic pollutants. However, traditional homogeneous Fenton systems have several limitations, such as slow reaction rates and the generation of iron sludge. In this study, a ferrocene-based catalytic ultrafiltration membrane was developed by UV photopolymerization. This membrane integrated Fenton reaction with membrane separation technology significantly enhances pollutant removal efficiency, prevents iron sludge formation, and provides self-cleaning properties to extend the service life of the membrane. The results indicated that the ferrocene groups are uniformly distributed on the membrane surface, greatly improving their catalytic efficiency. In heterogeneous Fenton reactions, M2 exhibited excellent catalytic activity, achieving a degradation rate of > 99.9% of methyl orange (MO) within 90 s. Additionally, under the synergistic effect of membrane filtration and catalysis, M2 efficiently removed humic acid (HA) and MO and demonstrated good reusability over multiple cycles. Moreover, under Fenton reaction conditions, M2 showed superior self-cleaning performance, achieving a high FRR value of 94.1%. Overall, this catalytic membrane enhanced pollutant removal efficiency through the combined effect of membrane separation and catalysis, effectively degrading small molecule dyes in the presence of natural organic matter, offering a novel approach to addressing water pollution.