Removal of Ketoprofen from Water by Sono-Activated Persulfate Oxidation

In this study, we evaluated the feasibility of treating water contaminated with ketoprofen (KET) by ultrasound (US) and sono-activated persulfate (US/PS) systems. The effects of different reaction parameters, such as the initial pharmaceutical compound concentration (C0), persulfate concentration, ultrasonic power, and initial pH of the solution (pHi) on the KET removal and reaction kinetics were investigated. Tert-butyl alcohol (TBA) was used as a chemical probe to identify the predominant radicals in the US and US/PS systems. The results demonstrated that the persulfate oxidant can be activated by US under neutral and alkaline conditions. Moreover, KET was predominantly degraded by hydroxyl radicals (HO.) generated by the activation of persulfate. Under alkaline conditions, the removal efficiency of KET improved with increasing amount of persulfate added. HO. was the dominant radical at a more alkaline pH in both US and US/PS systems, which was verified by the tert-butyl alcohol probe. These results provide insights into the treatment of water contaminated with pharmaceutical compounds. © 2020, Springer Nature Switzerland AG.