Fu Liu

Catalytic membrane is an appealing technology for eliminating refractory organic pollutants in comparison to conventional advanced oxidation methods. However, the application of this technology is constrained by the trade-off between membrane permeability and reactivity. Herein, we prepared a tubular macroporous catalytic membrane (MCM), which activated peroxymonosulfate to produce dominant singlet oxygen (¹O₂) and hydroxyl radicals (^•OH) in the macropore channel (∼130 nm). The optimized MCM membrane demonstrated catalytic filtration performance far beyond the state-of-the-art, achieving >99% degradation of antibiotics, dyes, and phenolic compounds while simultaneously exhibiting ultrafast permeance (645.3 L m^-2 h^-1 bar^-1). For the first time, we reveal the spatial distribution of shorter-lived ^•OH and long-lived ¹O₂ in the macropore channel via a diffusion-reaction kinetic model, which provides fundamental insights into how these two reactive oxygen species work synergistically to offer opportunities for breaking the permeability-reactivity trade-off. Furthermore, the MCM achieved robust and stable removal of total organic carbon for a real high-salinity wastewater, verifying its practical potential for treating refractory organics.

Efficient dye/salt separation poses a great challenge to nanofiltration (NF) membrane technology in the desalting sector of the dye synthesis industry. In this study, we fabricated a novel loose polyester NF membrane via an interfacial polymerization method using “hydroxyl-ammonium” biquaternary diethanolamine (MDET) and trimesoyl chloride. The molecular design of MDET provides a loose crosslinking network, showing high rejection of dyes and the passage of monovalent salt/divalent salt ions in the dye solution, exhibiting exceptional filtration efficiency with high selectivity. Furthermore, the membrane exhibits excellent operational stability for over 100 h, demonstrating superior antifouling properties and high resistance to chlorine. This study provides new insights into the role of dyes and mono- and divalent ions in desalination processes related to the dye synthesis industry.