Electrochemically activated peroxymonosulfate for the abatement of chloramphenicol in water: performance and mechanism

In this study, electrochemically activated peroxymonosulfate (EC/PMS) with a sacrificial iron electrode was used for the removal of chloramphenicol (CAP) from water. Compared to electrolysis alone, peroxymonosulfate (PMS) alone, and Fe 2+ /PMS, EC/PMS significantly enhanced the CAP degradation. Various parameters, such as the applied current, electrolyte concentration, and PMS dose, were investigated to optimize the process. In addition, acidic conditions facilitated the CAP degradation. The presence of Cl − slightly enhanced the CAP degradation, while both HCO 3 − and NO 3 − exhibited an inhibitory effect on the CAP degradation. The floccules were also analyzed after the reaction by XPS and XRD. Quenching experiments indicated that both sulfate radicals (SO 4 ●− ) and hydroxyl radicals (•OH) were responsible for the CAP degradation. In addition, the degradation products were identified by LC/TOF/MS, and the degradation pathways were proposed accordingly. These results indicated that EC/PMS is a promising treatment process for the remediation of water polluted by CAP.