Oxidative degradation of levofloxacin in aqueous solution by S2O82-/Fe2+, S2O82-/H2O2 and S2O82-/OH- processes: A comparative study

The performance of levofloxacin (LFX) degradation in aqueous solutions in ferrous ion-activated persulfate (S2O82-/Fe2+), peroxide-activated persulfate (S2O82-/H2O2), and base-activated persulfate (S2O82-/OH-) systems was evaluated and compared. The LFX degradation by all studied activated persulfate systems was divided into two oxidation periods: a fast degradation of target compound within the first minute and subsequent gradual oxidation within the remaining reaction time. Notably, without consideration of the first minute, the rest of the LFX degradation in the S2O8 (2-)/Fe2+ and S2O82-/H2O2 system followed the pseudo-first-order kinetic model. Among the studied activation techniques, the Fe2+-activated persulfate system demonstrated the highest efficacy in LFX degradation, mineralization and persulfate utilization, followed by the peroxide-activated persulfate oxidation. Generally, all studied sulfate radical-based advanced oxidation technologies proved to be promising tool for the treatment of LFX contaminated water/wastewater and, especially, groundwater. (C) 2015 Elsevier Ltd. All rights reserved.