Degradation of ciprofloxacin using UV-based advanced removal processes: Comparison of persulfate-based advanced oxidation and sulfite-based advanced reduction processes

In this study, the degradation of ciprofloxacin (CIP) in wastewater was investigated using UV-based sulfate radical advanced oxidation processes (SR-AOP) and UV-based advanced reduction processes (ARP). More specifically, a comparison of the UV-based persulfate advanced oxidation process (the UV/PS process) and the UV-based sulfite advanced reduction process (the UV/sulfite process) was made. Considering the UV-based SR-AOPs, the UV/PS process was much more efficient than the UV-based peroxymonosulfate advanced oxidation process ( the UV/PMS process), with pseudo first order reaction rate constants (k(obs)) of 0.752 and 0.145 min(-1), respectively. For the UV-based ARPs, the UV/sulfite process was the most efficient, compared to the UV/sulfide and the UV/dithionite process (k(obs), of 0.269,0.0157 and 0.0329 min(-1), respectively). The optimal process parameters for both the UV/PS and the UV/sulfite process were determined and the contribution of the produced reactive species were identified. For the UV/PS process, maximal CIP degradation was found at pH 8, and both center dot OH and center dot SO4-, were responsible for CIP degradation. For the UV/sulfite process, center dot H and center dot e(aq)(-) were responsible for CIP degradation, with center dot e(aq)(-1) being the predominant radical at pH 8.5. Although CIP degradation was much faster for the UV/PS process, the UV/sulfite process was determined to be much more efficient in the defluorination of GP. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, the efficiency of UV-based sulfate radical advanced oxidation processes (SR-AOP) and UV-based advanced reduction processes (ARP) in degrading ciprofloxacin (CIP) in wastewater was investigated. It was found that the UV/PS process was more efficient than the UV/PMS process in SR-AOPs, while the UV/sulfite process was the most efficient among ARPs. The optimal process parameters and the contribution of different reactive species were determined for each process.