Thin-Film Nanocomposite Membranes with Nature-Inspired MOFs Incorporated for Removing Fluoroquinolone Antibiotics

A nanofiltration membrane functionalized with metal-organicframeworks (MOFs) is promising to enhance micropollutant removal andrealize wastewater reclamation. However, the current MOF-based nanofiltrationmembranes still suffer from severe fouling problems with an indefinablemechanism when used for antibiotic wastewater treatment. Hence, wereport a nature-inspired MOF-based thin-film nanocomposite (TFN-CU)membrane to explore its rejection and antifouling behavior. Comparedwith unmodified membranes, the optimal TFN-CU5 membrane (with 5 mg center dot mL(-1) C-UiO-66-NH2) had high water permeance(17.66 +/- 1.19 L center dot m(-2)center dot h(-1)center dot bar(-1)), exceptional rejection for norfloxacin(97.92 +/- 2.28%) and ofloxacin (95.36 +/- 1.03%), and excellentlong-term stability for treating synthetic secondary effluent withantibiotic rejection over 90%. Furthermore, it also showed superiorantifouling capability (flux recovery up to 95.86 +/- 1.28%) inbovine serum albumin (BSA) filtration after fouling cycles. Derivingfrom the extended Derjaguin-Landau-Verwey-Overbeek(XDLVO) approach, the antifouling mechanism between BSA and the TFN-CU5membrane was mainly attributed to the inhibited adhesion forces becausethegrowing short-ranged acid-base interaction caused repulsiveinterfacial interactions. It is further revealed that BSA foulingbehavior is slightly retarded under an alkaline environment, whilestrengthened in the presence of calcium ions and humic acid, as wellas high ionic strength. In short, the nature-inspired MOF-based TFNmembranes possess exceptional rejection and organic fouling resistance,giving insights into the design of antifouling membranes during antibioticwastewater reclamation.

Automated summary

Researchers have developed a nanofiltration membrane functionalized with metal-organic frameworks (MOFs) to enhance micropollutant removal and wastewater reclamation. The nature-inspired MOF-based thin-film nanocomposite (TFN-CU) membrane showed high water permeance, exceptional rejection for antibiotics, and excellent long-term stability. It also demonstrated superior antifouling capability in protein filtration after fouling cycles. These findings provide valuable insights for the design of antifouling membranes in antibiotic wastewater reclamation.