LAUSR

Abstract This paper presents ammonia-enhanced oxidation of flumequine (FLU), a representative fluoroquinolone antibiotic, by ferrate(VI) (FeVIO42−, Fe(VI)). The second-order rate constants (k) without ammonia were 9.34 ± 1.04 and 1.16 ± 0.04 M−1 s−1 at pH 8.0 and 9.0, respectively. These values of k increased linearly with the concentrations of ammonia ([NH4+] + [NH3]) and were 50.00 ± 6.20 and 14.42 ± 1.44 M−1 s−1 for 0.01 M ammonia at pH 8.0 and 9.0, respectively. Oxidized products (OPs) of FLU in the presence of ammonia were identified using liquid chromatography-high resolution mass spectrometry. When ammonia was present in the solution, the distribution of OPs changed from the profile of OPs obtained in the absence of ammonia. The quantitative microbiological assays of Fe(VI)-treated FLU solutions using Escherichia coli and Bacillus subtilis indicated that Fe(VI) oxidation could effectively eliminate the residual antibacterial activity of FLU. Removal experiments demonstrate that the presence of ammonia could also enhance the removal of FLU from water containing humic acid, river water, and wastewater.