Enhanced removal of antibiotic-resistant genes by sodium persulfate catalyzed by nanoscale zero-valent iron modified by <i>Ginkgo biloba</i> L. leaf

ABSTRACT In this study, nanoscale zero-valent iron (nZVI) modified by Ginkgo biloba L. leaf (G-nZVI), as an effective catalyst, exhibited excellent activation of sodium persulfate (PS), which could achieve higher removal efficiency of antibiotic-resistant genes (ARGs) in the Fen River than PS + nZVI system. This study utilizes forestry waste to address the limitations of using Fe2+/nZVI as an activator for the removal of ARGs. This approach adheres to the principle of employing waste to treat waste. The technology converts G. biloba L. leaf into plant extracts that are rich in a variety of bioactive components, rather than purifying natural biomolecules, which decreases operational complexity. In addition, the G-nZVI + PS system demonstrates superior removal performance to single components in the system. Consequently, the mechanism underlying the G-nZVI + PS treatment is attributed to peroxidation induced by radicals. In this context, the results of ARG removal by G-nZVI + PS with different G. biloba L. leaf /FeSO4·7H2O volume ratios indicated that the G. biloba L. leaf enhanced the conversion of Fe3+ to Fe2+, thereby generating more radicals through electron transfer between the biomass and G-nZVI. This research underscores the advantages of modifying G. biloba L. leaf for improved catalytic efficiency and the role of the components within the system.