Photo-assisted degradation of 2, 4, 6-trichlorophenol by an advanced reduction process based on sulfite anion radical: Degradation, dechlorination and mineralization

Yazdanbakhsh, Ahmadreza; Eslami, Akbar; Moussavi, Gholamreza; Rafiee, Mohammad; Sheikhmohammadi, Amir

doi:10.1016/j.chemosphere.2017.10.023

Cited by 93 publications

(39 citation statements)

References 36 publications

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“…When further increasing the sulfite concentration from 1 to 2 mM, kobs only increased slightly from 0.269 to 0.297 min -1 . This trend can, in a similar way as the UV/PS process, be attributed to the occurrence of radical-radical interactions (Jung et al, 2015;Yazdanbakhsh et al, 2018).…”

Section: Influence Of Oxidant/reductant Concentrationmentioning

confidence: 59%

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

Milh

Cabooter

et al. 2021

Science of The Total Environment

100

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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.

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Section: Influence Of Oxidant/reductant Concentrationmentioning

confidence: 59%

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

Milh

Cabooter

et al. 2021

Science of The Total Environment

100

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“…At neutral pH, H • may show increased contribution due to the conversion of e aq to H • (pKa(H • )=9.6 [12]). Recently, several works reported that sulfite radical (SO • ) also played an important role during degradation of organic pollutants by sulfite-mediated processes [13][14][15]. Addition to unsaturated bond and H-abstraction are the two main reaction types for SO • with organics [16].…”

Section: Identification Of Main Reactive Species For Mcaa Degradationmentioning

confidence: 99%

Fast Degradation of Monochloroacetic Acid by BiOI-Enhanced UV/S(IV) Process: Efficiency and Mechanism

Wang

Liu

2019

Catalysts

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Iodide ( I − ) could promote ultraviolet-activated S(IV) processes (UV/S(IV)) and degrade aqueous halogenated organic compounds and hazardous oxoanions. With the interest of promoting use of this technology, this study investigated the feasibility of using bismuth oxyiodide (BiOI) as an I − source to enhance UV/S(IV) where monochloroacetic acid (MCAA) was selected as a testing model compound. Degradation of MCAA by UV/S(IV) increased by 50% in presence of BiOI. Results of competitive kinetics indicated that the promotion effect brought by BiOI mainly originated from its sustainable release of I − , and subsequent enhanced generation of hydrated electrons. Electron spin resonance detection and fluorescence characterization proved increased formation of sulfite radical, resulting from sulfite oxidation by UV-excited BiOI. However, the sulfite radical only made a small contribution (9%) to MCAA degradation due to its moderate reactivity toward MCAA (4.2 × 105 M−1·s−1). UV/S(IV) combined with BiOI significantly decreasing the biotoxicity of MCAA solution. BiOI can be regenerated using I − -containing solution. Our findings provide evidence that BiOI is a promising I − source and photocatalyst, which progresses the I − -assisted UV/S(IV) process towards practical application.

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“…5(a) for 0 mM sulphite), indicating that direct photolysis is not the main mechanism for 2,4-DCP degradation. Additionally, if direct photolysis would dominate the degradation mechanism, a higher sulphite dosage would lead to a decrease in the average light intensity to be absorbed by 2,4-DCP, thereby reducing the k obs [23,39]. The obtained experimental results (as shown in Fig.…”

Section: Effect Of Sulphite Dosementioning

confidence: 65%

“…Hence the experimental conditions used in this study are again not optimal for the formation of reactive ions originating from sulphide. It has been suggested that e aq − and SO 3 % − , formed by sulphite under UV irradiation with a wavelength of 254 nm [30,31], are very strong reductive species with a reduction potential of −2.9 V [39] and −0.73 V [40], respectively. Liu and Li, for example, demonstrated that the high degradation rate and dechlorination efficiency of vinyl chloride (VC) and monochloroacetic acid (MCAA) via the sulphite/UV process were due to the highly reductive capability of e aq − and SO 3 % − [22,41].…”

Section: Type Of Reductive Agentmentioning

confidence: 99%

“…The initial increase in sulphite concentration resulted in a higher removal efficiency with a proportional increase in k obs , due to a higher absorbance of incident light by sulphite and a higher production of radicals responsible for the degradation [46,47]. At higher radical concentration, however, the produced radicals start reacting with each other and with the intermediates that are produced during the process (now acting as scavengers), leading to a larger consumption of radicals and hence explains the inhibition of the proportional increase of degradation rate constant [24,39]. Fig.…”

Section: Effect Of Sulphite Dosementioning

confidence: 99%

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Effects of process variables and kinetics on the degradation of 2,4-dichlorophenol using advanced reduction processes (ARP)

Cabooter

Dewil

2018

Journal of Hazardous Materials

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This study aims at investigating the efficiency and kinetics of 2,4-DCP degradation via advanced reduction processes (ARP). Using UV light as activation method, the highest degradation efficiency of 2,4-DCP was obtained when using sulphite as a reducing agent. The highest degradation efficiency was observed under alkaline conditions (pH = 10.0), for high sulphite dosage and UV intensity, and low 2,4-DCP concentration. For all process conditions, first-order reaction rate kinetics were applicable. A quadratic polynomial equation fitted by a Box-Behnken Design was used as a statistical model and proved to be precise and reliable in describing the significance of the different process variables. The analysis of variance demonstrated that the experimental results were in good agreement with the predicted model (R = 0.9343), and solution pH, sulphite dose and UV intensity were found to be key process variables in the sulphite/UV ARP. Consequently, the present study provides a promising approach for the efficient degradation of 2,4-DCP with fast degradation kinetics.

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Photo-assisted degradation of 2, 4, 6-trichlorophenol by an advanced reduction process based on sulfite anion radical: Degradation, dechlorination and mineralization

Cited by 93 publications

References 36 publications

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

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

Fast Degradation of Monochloroacetic Acid by BiOI-Enhanced UV/S(IV) Process: Efficiency and Mechanism

Effects of process variables and kinetics on the degradation of 2,4-dichlorophenol using advanced reduction processes (ARP)

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