Photo-degradation of clofibric acid by ultraviolet light irradiation at 185 nm

Li, Wenzhen; Gu, Xiaoli; Qiu, Zhaofu; Fan, Jinxia; Lin, Kuangfei

doi:10.2166/wst.2009.690

Cited by 13 publications

(4 citation statements)

References 12 publications

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“…The considerable difference in the rate constants with varying initial pH might be due to the change in the reaction species of CA. The p K a value of CA was 3.18, 50 and its species distribution is shown in Fig. 4 .…”

Section: Resultsmentioning

confidence: 95%

Aquatic photodegradation of clofibric acid under simulated sunlight irradiation: kinetics and mechanism analysis

et al. 2018

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a Clofibric acid is one of the most frequently detected pharmaceuticals in various aquatic environments.Photodegradation of clofibric acid in water under simulated sunlight was investigated. The effects of different initial concentrations, pH conditions and dissolved oxygen were examined. Photodegradation of clofibric acid followed a pseudo-first-order kinetics model, and the rate decreased gradually with the increasing initial concentration of clofibric acid. Dissolved oxygen inhibited the photodegradation of clofibric acid. As a result of varying reaction species of clofibric acid, the initial pH conditions greatly influenced its photodegradation. Quenching experiments showed that the self-sensitization process via $OH and

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Section: Resultsmentioning

confidence: 95%

Aquatic photodegradation of clofibric acid under simulated sunlight irradiation: kinetics and mechanism analysis

et al. 2018

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“…Current traditional wastewater and drinking water treatment processes, such as coagulation, sedimentation and filtration, and biological processes, do not efficiently remove CA [ 8 ]. It was reported that ultraviolet (UV) photolysis could efficiently degrade CA in wastewater [ 9 ]. Generally, UV photolysis is used as the disinfection process in wastewater treatment plant [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

Degradation of clofibric acid in UV/chlorine disinfection process: kinetics, reactive species contribution and pathways

Tang¹,

Shi²,

Liu³

et al. 2018

R. Soc. open sci.

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As a potential endocrine disruptor, clofibric acid (CA) was investigated in this study for its degradation kinetics and pathways in UV/chlorine process. The results showed that CA in both UV photolysis and UV/chlorine processes could be degraded via pseudo-first-order kinetics, while it almost could not be degraded in the dark chlorination process. The observed rate constant (kobs) in UV photolysis was 0.0078 min−1, and increased to 0.0107 min−1 combining with 0.1 mM chlorine. The kobs increased to 0.0447 min−1 with further increasing the chlorine dosage from 0.1 to 1.0 mM, and reached a plateau at higher dosage (greater than 1.0 mM). The higher kobs was obtained at acid solution rather than basic solution. Moreover, the calculated contributions of radical species to kobs indicated that the HO• contributed significantly to CA degradation in acidic conditions, while the reactive chlorine species and UV direct photolysis dominated in neutral and basic solution. The degradation of CA was slightly inhibited in the presence of HCO3− (1 ∼ 50 mM), barely affected by the presence of Cl− (1 ∼ 200 mM) and greatly suppressed by humic acid (0 ∼ 5 mg l−1). Thirteen main degradation intermediates and three degradation pathways of CA were identified during UV/chlorine process.

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“…Direct VUV photolysis of water can produce an appreciable amount of • OH for oxidative decomposition of organic pollutants without any additional power input. As a result, the VUV/UV process has been applied to enhance the disinfection of pathogens and the removal of dissolved organic matter and various micropollutants in water and wastewater. − For UV-based AOPs (e.g., UV/chlorine), if a VUV/UV LP lamp (using synthetic quartz) is used as the light source, a higher efficiency can be expected than for a conventional UV LP lamp.…”

Section: Introductionmentioning

confidence: 99%

VUV/UV/Chlorine as an Enhanced Advanced Oxidation Process for Organic Pollutant Removal from Water: Assessment with a Novel Mini-Fluidic VUV/UV Photoreaction System (MVPS)

Qiang

Hou

et al. 2016

Environ. Sci. Technol.

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Vacuum ultraviolet (VUV) and ultraviolet (UV)/chlorine processes are regarded as two of many advanced oxidation processes (AOPs). Because of the similar cost of VUV/UV and UV lamps, a combination of VUV and UV/chlorine (i.e., VUV/UV/chlorine) may enhance the removal of organic pollutants in water but without any additional power input. In this paper, a minifluidic VUV/UV photoreaction system (MVPS) was developed for bench-scale experiments, which could emit both VUV (185 nm) and UV (254 nm) or solely UV beams with a nearly identical UV photon fluence. The photon fluence rates of UV and VUV output by the MVPS were determined to be 8.88 × 10 −4 and 4.93 × 10 −5 einstein m −2 s −1 , respectively. The VUV/UV/chlorine process exhibited a strong enhancement concerning the degradation of methylene blue (MB, a model organic pollutant) as compared to the total performance of the VUV/UV and UV/chlorine processes, although the photon fluence of the VUV only accounted for 5.6% of that of the UV. An acidic pH favored MB degradation by the VUV/ UV/chlorine process. The synergistic mechanism of the VUV/UV/chlorine process was mainly ascribed to the effective use of • OH for pollutant removal through formation of longer-lived secondary radicals (e.g.,• OCl). This study demonstrates that the new VUV/UV/chlorine process, as an enhanced AOP, can be applied as a highly effective and energy-saving technology for small-scale water and wastewater treatment.

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Photo-degradation of clofibric acid by ultraviolet light irradiation at 185 nm

Cited by 13 publications

References 12 publications

Aquatic photodegradation of clofibric acid under simulated sunlight irradiation: kinetics and mechanism analysis

Aquatic photodegradation of clofibric acid under simulated sunlight irradiation: kinetics and mechanism analysis

Degradation of clofibric acid in UV/chlorine disinfection process: kinetics, reactive species contribution and pathways

VUV/UV/Chlorine as an Enhanced Advanced Oxidation Process for Organic Pollutant Removal from Water: Assessment with a Novel Mini-Fluidic VUV/UV Photoreaction System (MVPS)

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