Degradation of N-nitrosamines and 1,4-dioxane using vacuum ultraviolet irradiation (UV254+185 nm or UV172 nm)

Fujioka, Takahiro; Kodamatani, Hitoshi; Tran, Hai Duc Minh; Fujioka, Atsushi; Hino, Kazunori; Yoshikawa, Takumi; Inoue, Daisuke; Ikehata, Keisuke

doi:10.1016/j.chemosphere.2021.130326

Cited by 17 publications

(7 citation statements)

References 37 publications

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“…The direct irradiation of UV 254 light did not effectively degrade dioxane, suggesting that intermediate products generated during the degradation process of organic pollutants might compete with PDS for UV radiation. This competition inhibited the formation of SO − 4 and reduced the likelihood of collision between dioxane and reactive free radicals [37,39]. Therefore, it was necessary to increase the intensity of UV irradiation in order to enhance the degradation efficiency when treating high concentrations of dioxane.…”

Section: Parameters Of Uv/pds Degradation Of Dioxanementioning

confidence: 99%

Effective Degradation of 1,4-Dioxane by UV-Activated Persulfate: Mechanisms, Parameters and Environmental Impacts

Zhu,

Qiu,

Wang

et al. 2024

Water

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There is more and more research focusing on the removal of dioxane by advanced oxidation technology at this stage, and this study investigated the efficacy of an advanced oxidation system with UV-activated persulfate (UV/PDS). This method had the advantages of fast reaction rate, simple equipment and convenient operation. Free radical quenching test and electron paramagnetic resonance (EPR) analysis showed that the main active radicals in the reaction system were SO4− and ·OH. This study also investigated that the optimal parameters were the initial PDS dosage of 3 mM, the UV intensity of 0.190 mM/cm2, the pH between 5 and 7 and the initial dioxane concentration of 50 mg/L. Additionally, after a reaction time of 150 min, the total organic carbon (TOC) content still remained at 83.53%, which revealed that the mineralization degree of organic matter was not fully achieved through UV/PDS treatment. The concentration of SO42− in the reaction system was 74.69 mg·L−1, which complied with the standard concentration specified. Furthermore, the cytotoxicity of the system exhibited an initial increase followed by a subsequent decrease, under the influence of the intermediates. It showed that the technology could efficiently degrade organic pollutants.

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Section: Parameters Of Uv/pds Degradation Of Dioxanementioning

confidence: 99%

Effective Degradation of 1,4-Dioxane by UV-Activated Persulfate: Mechanisms, Parameters and Environmental Impacts

Zhu,

Qiu,

Wang

et al. 2024

Water

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“…For effective direct photolysis, there must be an appropriate overlap between the investigated compound absorption spectrum (Supplementary Figure S1) and the corresponding radiation source spectrum (Bonvin et al, 2013). Fujioka et al (2020) have determined that UV-LED irradiation sources are less effective than UV irradiation sources for degrading organic compounds with absorption maximums in the UV area due to the longer emission wavelengths of the UV-LED lamps.…”

Section: Removal Of Nadolol and Its Degradation Intermediates From Watermentioning

confidence: 99%

“…A minor disadvantage of photolysis under UV irradiation is using Mercury lamps as a radiation source. In recent years, UV-LED has gained considerable attention as an alternative radiation source because it has a long lifetime and is mercuryfree (Fujioka et al, 2020). In industry, H 2 O 2 is used as an effective bleach instead of chlorine-containing agents.…”

Section: Introductionmentioning

confidence: 99%

Exploring the influence of free radicals on photolytic removal of nadolol from water: Mechanism of degradation and toxicity of intermediates

Bilić

Savanović

Armaković

et al. 2023

Front. Environ. Sci.

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β-blockers are known to have negative effects on fish and other aquatic animal species, so their removal is key for preserving aquatic ecosystems. To reduce the risks related to β-blockers, it is necessary to assess their effects and develop more effective treatments such as advanced oxidation processes. Improving sewage treatments is a critical approach to reducing β-blockers in aquatic environments. In this work, for the first time, the direct and indirect photolysis of nadolol (NAD) was investigated under different light sources (simulated solar (SS), UV-LED, and UV radiations) in ultrapure water. Indirect photolysis by H2O2 showed 1.5, 2.1, and 5.6 times higher NAD degradation efficiency than direct photolysis under mentioned irradiations. This effect was particularly pronounced in the presence of UV radiation, in which the degradation efficiency of NAD was the highest (80.2%). Computational analysis based on density functional theory calculations, together with the results of NAD photodegradation efficiency in the presence of radical scavengers (isopropanol and benzoquinone), was used to propose the NAD degradation mechanism. Sixteen degradation intermediates were proposed, along with their NMR chemical shifts. Also, this study analyzed the degree of catalase activity, lipid peroxidation, and hydroxyl radicals neutralization of NAD and its photodegradation mixtures obtained after indirect photolysis. The degree of mineralization and in vitro toxicity of NAD and its degradation intermediates obtained in the presence of UV/H2O2 were assessed.

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“…Ultraviolet (UV) irradiation is based on hydroxyl radicals or persulfate radicals utilizing UV lamps combined with O 3 , H 2 O 2 , chlorine or persulfate for the degradation of organic pollutants [8][9]. UV lamps at 185 nm and 254 nm are the main lamps used in UV irradiation for the wastewater treatment [10][11].…”

Section: Introductionmentioning

confidence: 99%

Degradation of Reactive Red (B-3BF) Dye Wastewater Using UV Irradiation (254/185nm) with Sodium Persulfate in a Pilot UV Device

Wang,

Li,

Wan

et al. 2024

Preprint

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Two low-pressure ultraviolet (UV) lamps at 185/254 nm with sodium persulfate in a pilot UV device were utilized for the degradation of reactive red (B-3BF) dye wastewater compared with two UV lamps at 185/185 nm and two UV lamps at 254/254 nm. The degradation performances of UV irradiation (254/185 nm) with sodium persulfate under different degradation times, flow rates, initial pH, initial Na2S2O8 concentrations and initial dye concentrations were investigated. The experimental results illustrated that the degradation percentage of B-3BF dye could reduce to 90.42% with the energy consumption of 85.1 kWh/kg and the residual dye concentration of 1.92 mg/L by UV irradiation (254/185 nm) with initial Na2S2O8 concentration of 1.5 mmol/L and initial dye concentration of 20 mg/L. In addition, degradation performance of B-3BF dye wastewater by UV irradiation (254/185 nm) with sodium persulfate was more effective than those of UV irradiation (254/254 nm) and UV irradiation (185/185 nm). Therefore UV irradiation (254/185 nm) with sodium persulfate was promising for the degradation of B-3BF dye wastewater.

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Degradation of N-nitrosamines and 1,4-dioxane using vacuum ultraviolet irradiation (UV254+185 nm or UV172 nm)

Cited by 17 publications

References 37 publications

Effective Degradation of 1,4-Dioxane by UV-Activated Persulfate: Mechanisms, Parameters and Environmental Impacts

Effective Degradation of 1,4-Dioxane by UV-Activated Persulfate: Mechanisms, Parameters and Environmental Impacts

Exploring the influence of free radicals on photolytic removal of nadolol from water: Mechanism of degradation and toxicity of intermediates

Degradation of Reactive Red (B-3BF) Dye Wastewater Using UV Irradiation (254/185nm) with Sodium Persulfate in a Pilot UV Device

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