Catalytic ozonation mechanisms of Norfloxacin using Cu-CuFe2O4

As an easily recoverable, environmentally friendly and cost-effective catalyst, CuFe2O4 is a promising candidate for the catalytic ozonation of antibiotics in wastewater. However, its catalytic activity is restricted due to its limited active sites and low electron transfer efficiency. In this study, cetyl trimethyl ammonium bromide (CTAB) and Cu-0 were doped with CuFe2O4 to introduce more O-V, providing more active sites and improving electron transfer efficiency. Experimental results show that the optimum removal efficiency of the catalytic ozonation of Norfloxacin (NOR, a widely used antibiotic) using CTAB doped with Cu-CuFe2O4 as the catalyst is 81.58% with a first-order reaction kinetics constant of 0.03967 min(-1). The associated O-3 and catalyst dosages are 2.72 mg.L-1 and 0.1 g.L-1, respectively, which are 1.63 times and 2.22 times higher than those in an equivalent O-3 system. O-V can provide generation sites for surface hydroxyl groups and trigger center dot O-2(-) and O-1(2) as the main active oxygen species. The synergistic redox cycles of Fe2+/Fe3+ and Cu-0/Cu2+ accelerate electron transfer efficiency. The possible degradation pathways of NOR are identified as defluorination, naphthyridine ring-opening and piperazine ring-opening. In summary, this work proposes a new strategy for the modification of CuFe2O4 catalysts and provides new insights into the catalytic ozonation mechanisms for NOR removal.

Automated summary

CuFe2O4 is a promising catalyst for the catalytic ozonation of antibiotics in wastewater due to its easily recoverable, environmentally friendly and cost-effective properties. However, its catalytic activity is limited by its lack of active sites and low electron transfer efficiency. In this study, CTAB and Cu-0 were doped with CuFe2O4 to introduce more O-V, which provided more active sites and improved electron transfer efficiency. Experimental results showed that the catalyst made of CTAB doped with Cu-CuFe2O4 achieved an optimum removal efficiency of 81.58% for Norfloxacin, with a first-order reaction kinetics constant of 0.03967 min(-1).