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

Abstract

In this study, the degradation of ciprofloxacin (CIP) in wastewater was investigated using UVbased 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. As for 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 (kobs) 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 (kobs 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 •OH and •SO4were responsible for CIP degradation. For the UV/sulfite process, •H and •eaqwere responsible for CIP degradation, with •eaqbeing 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 CIP.

Kinetic study on degradation of micro-organics by different UV-based advanced oxidation processes in EfOM matrix

“…These rate constants are similar to the 10 3 -10 11 M -1 s -1 range of second-order rate constants for the reaction of organics with HO • presented in the literature: these are compared with other studies in Table S5. The results of Yang and NAGARNAIK P M-3.3×10 4 (mg-C/L) -1 s -1 and (7.1±0.81) ×10 4 (mg-C/L) -1 s -1 , respectively (Nagarnaik and Boulanger, 2011;Yang et al, 2016)-are very similar to our findings. In the sulfate radical-mediated oxidation system, the error of the determined rate constant ( 𝑘 𝑆𝑂 4 −⋅ ,𝐸𝑓𝑂𝑀 =(5.027±0.643)×10 2 ((mg-C/L) -1 s -1 ) in this study was small, indicating the reliability of the measurement method.…”

“…(Hori et al, 2005;Yang et al, 2014) SO4 -• is generated via the activation of peroxymonosulfate (HSO5 -, PMS) or persulfate (S2O8 2-, PS) by UV, heat or transition metals. (Matta et al, 2011;Zhou et al, 2013) , (Milh et al, 2021) UV/persulfate possesses several advantages, including stability of the precursors (PMS or PS), ease of storage and transportation, high water solubility, versatile activation strategies and a wide operating pH range. (And and Dionysiou, 2004;Das, 2017) , (Giannakis et al, 2021) UV/Cl is an emerging AOP alternative to the UV/H2O2 process, as it produces HO • and reactive chlorine species (RCS).…”

Removal of sulfamethoxazole by ferrous iron activation of persulfate: Optimization of dosing strategy and degradation mechanism

“…In this process, the radicals are produced through scission of the peroxide bond of the PS molecule. Research 4 through this process is rather slow, therefore 4 - (Milh et al, 2021c). This also shows in the results obtained for heat-activated PMS oxidation: here, a 1% was reported, while according to Eq.…”

Hydrogen Peroxide Activated by Biochar-Supported Sulfidated Nano Zerovalent Iron for Removal of Sulfamethazine: Response Surface Method Approach

“…Kosutic found a comparatively higher removal effect based on the combined use of a nanomembrane and reverse osmosis membrane, which however cannot be implemented due to membrane fouling [ 8 ]. Advanced oxidation methods (AOPs) are physicochemical processes used to degrade organic substances that have a high reaction rate, strong oxidation ability, and facile control and have therefore been extensively investigated for application to water treatment [ 9 , 10 , 11 ]. These methods involve the use of hydrogen peroxide (H 2 O 2 ), which is catalyzed by various materials to produce strong oxidizing hydroxide radicals (·OH) that degrade organic matter at a high rate and with a high efficiency [ 12 , 13 ].…”