Fast degradation of 5-fluorouracil in urban wastewater by peroxymonosulfate activation using MgMnFe-layered double hydroxide
摘要
The use of MgMnFe-layered double hydroxide (LDH) to activate peroxymonosulfate (PMS) for the rapid degradation of the anticancer drug 5-fluorouracil (5-FU) in purified water and pretreated urban wastewater was investigated for the first time, under near-neutral pH and dark conditions. The catalyst showed a lamellar structure with carbonate anions, high crystallinity, and phase purity confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The Brunauer–Emmett–Teller method yielded a specific surface area of 94.93 m2g−1, average pore diameter of 3.57 nm and a total pore volume of 0.344 cm3g−1. A complete degradation of 5-FU was achieved in 10 min in purified water and 240 min in pretreated urban wastewater, using 0.4 mM PMS and 0.5 g L⁻1 MgMnFe-LDH. Scavenger tests revealed that furfuryl alcohol and methanol inhibited the 5-FU degradation by 91% and 42%, respectively, while tert-butanol had a smaller impact, indicating that 1O2 and SO4·− are the main reactive species, with a minor contribution from HO·. The presence of 1O2 and HO· was confirmed by electron paramagnetic resonance spectroscopy. The catalyst remained stable and active over four successive cycles. These results demonstrate the potential of MgMnFe-LDH as an efficient catalyst for advanced water treatment, particularly in the degradation of 5-FU, through the generation of both radical and non-radical reactive oxygen species.
Graphical abstract