Journal of Cleaner Production
·
2023
·
IF 11.1
Qi Wang,Nan Huang,Wenlong Wang,Yunpeng Wu,Song Xue,Hongwei Xu,Zhuo Chen,Yinhu Wu,Qianyuan Wu,Hongying Hu
Urea in the ultrapure water production process threatens semiconductor manufacturing . This work proposed a urea removal strategy involving the VUV/UV/chlorine process in an acidic solution to achieve high-efficiency urea removal. VUV/UV/chlorine could thoroughly remove urea of 2 mg/L within 9 min at pH 3. A TN removal rate of 70% and a dissolved organic carbon removal rate of 84% were achieved in the urea degradation process . The decrease in pH and the increase in oxidant dosage could improve urea removal efficiency. The presence of chloride anion could improve urea removal by 55–85%. Based on the radical probe and quenching experiments, free radicals accounted for more than 90% of urea removal. •Cl 2 − and •OH were calculated to contribute approximately 36% and 22%, respectively, to urea removal. •Cl and •ClO together contributed less than 32%. The chlorination of urea was responsible for less than 10% of urea removal. Nitrogen in urea was transformed efficiently into inorganic nitrogen (N 2 , ammonium, and nitrate with a rough ratio of 6:1:1.1). Organic chlorine products formed in the urea degradation process took up less than 3% in all chlorine element and was converted into chloride anion finally.
研究领域:
环境科学
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水处理
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化学工程
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
·
IF 12.2
Huimei Pan,Baiyang Chen
Although UV and/or VUV tandem I – are often proposed as advanced reduction processes (ARPs) to eliminate micropollutants by generating e aq – , the fate of I – and its byproducts formation remain to be explored. Therefore, this study investigated the iodine species evolution during UV/I – and UV/VUV/I – processes under different influencing factors. Results show that UV/VUV oxidized most of I – to IO 3 – whereas UV only oxidized a portion of I – to intermediate reactive iodine species (RISs, including I 2 , HOI, and I 3 – ); meanwhile, substantial H 2 O 2 was generated only in UV/VUV/I – process but not in UV/I – process, proving that UV/VUV owns stronger oxidation ability than UV alone. Spiking I – into water exerted triple-sided effects by consuming •OH, generating e aq – , and shielding light, thus complicating the systems. Holistically, increasing pH or decreasing dissolved oxygen converted oxidizing environment into reducing condition and caused less RISs formation, especially for UV/VUV/I – . For oxyhalides , neither UV/I – nor UV/VUV/I – degraded ClO 4 – . While UV/I – cannot remove ClO 3 – , UV/VUV/I – reduced ClO 3 – to Cl – . Expectedly, both UV/I – and UV/VUV/I – reduced BrO 3 – to Br – more efficiently than UV and UV/VUV, confirming that I – can enhance the reduction capacities of UV/VUV and UV technologies .
研究领域:
环境科学
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水处理
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化学工程
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光化学
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Chen Ling,Chaolin Li,Aiping Liang,Wenhui Wang
Microplastics (MPs) pose a severe threat to the environment and human health, and effective treatment techniques are urgently desired to prevent the global spread of MPs pollution. However, efficient degradation of MPs remains difficult. Herein, vacuum ultraviolet (VUV) activated peroxymonosulfate (PMS) was firstly proposed as a promising technique for the degradation of polyethylene MPs. The weight loss of MPs reaches as high as 51.5% under mild conditions ([PMS] = 32 mmol/L, initial pH = 7, [MPs] = 1 g/L, [Time] = 48 h), which is the record performance achieved at room temperature and ambient pressure for MPs degradation. The excellent degradation performance is uncovered to originate from the synergistic effect of VUV and activated PMS. Direct photolysis of VUV can rapidly oxidize the surface of MPs to reduce its hydrophobicity and thus enhance the adsorption of reactive oxidation species (i.e., SO 4 ⋅− and HO ⋅ ) rooted from the VUV activated PMS, which was further confirmed by DFT calculations. The degradation of MPs repeatedly undergoes the process of VUV photolysis oxidation of the surface, degradation via VUV/UV/PMS-derived reactive oxidation species, shedding, and re-exposure of the new surface via VUV photolysis oxidation. This study highlights the unique role of the VUV photolysis in MPs degradation, paving a new route for designing practical MPs pollution remediation techniques.
研究领域:
环境科学
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化学工程
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材料科学
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高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Hong Liu,Ruibao Jia,Xiaodong Xin,Weilin Guo,Hong Zhang,Mingquan Wang
N -ethylperfluorooctane sulfonamidoacetic acid (N-EtFOSAA) is a precursor of perfluorooctane sulfonate and has seen increased production and usage in numerous developing and emerging industrialized countries. However, it has been proven toxic. This study presents the first investigation into the treatability of N-EtFOSAA utilizing the vacuum ultraviolet (VUV)/peroxydisulfate (PDS) and VUV/sulfite (SF) redox processes. The results demonstrate that a relatively high reaction rate constant of 0.0364 min −1 , but a low defluorination rate of 43.7 % and a total organic carbon (TOC) removal extent of 30.5 % were obtained in the VUV/PDS process. By contrast, a higher defluorination rate of 77.1 % and a TOC removal extent of 45.1 %, along with the generation of a series of fluorinated intermediates, were obtained in VUV/SF. Combined with theoretical calculations and the identification of intermediates, distinctive removal pathways in the oxidation and reduction processes were speculated. We observed that the VUV/PDS process led to an increase in the aquatic toxicity of N-EtFOSAA, whereas the VUV/SF process resulted in a decrease. The findings illustrate that the reductive degradation of N-EtFOSAA is more feasible through the synergistic interaction between hydrated electrons and hydroxyl radicals.
研究领域:
环境科学
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化学工程
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高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2019
·Vol. 32
·期 2
·259-266
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IF 0.791
Song Wen-tao,Hu Yong-jun,Jin Shan,Li Yu-jian
The radiation damage of biomolecules, in particular with aliphatic compound, has been extensively studied. Morpholine is a typical six-membered aliphatic heterocyclic compound. In the present work, photoionization and dissociation of the morpholine monomer and subsequent fragmentations have been investigated by synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. The vertical ionization energy of morpholine monomer is 8.37±0.05 eV, which agrees reasonably well with a theo-retical value 8.41 eV of morpholine. Experimentally observed fragmentation of morpholine ( m/z =87 amu) gives rise to m/z =86 amu, m/z =57 amu, and m/z =29 amu. Based on experimental and theoretical results, it is found that the m/z =86 amu is produced by losing H atom, the m/z =57 amu is formed by the elimination of CH 2 O with a ring-opening process, the m/z =29 amu is generated by further dissociation of the fragment m/z =57 amu (C 3 H 7 N) + by the elimination of C 2 H 4 . This finding would provide valuable insight into the photo-damage of aliphatic compounds, which may be related to living cells and other biological system.
研究领域:
生物化学
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分子生物学
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物理学
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高影响因子
JOURNAL OF CHEMICAL PHYSICS
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2015
·Vol. 142
·期 2
·
IF 2.952
Xiao Weizhan,Hu Yongjun,Li Weixing,Guan Jiwen,Liu Fuyi,Shan Xiaobin,Sheng Liusi
While methyl transfer is well known to occur in the enzyme- and metal-catalyzed reactions, the methyl transfer in the metal-free organic molecules induced by the photon ionization has been less concerned. Herein, vacuum ultraviolet single photon ionization and dissociation of ethanol dimer are investigated with synchrotron radiation photoionization mass spectroscopy and theoretical methods. Besides the protonated clusters cation (C 2 H 5 OH) ⋅ H + (m/z = 47) and the β-carbon-carbon bond cleavage fragment CH 2 O ⋅ (C 2 H 5 OH)H + (m/z = 77), the measured mass spectra revealed that a new fragment (C 2 H 5 OH) ⋅ (CH 3 ) + (m/z = 61) appeared at the photon energy of 12.1 and 15.0 eV, where the neutral dimer could be vertically ionized to higher ionic state. Thereafter, the generated carbonium ions are followed by a Wagner-Meerwein rearrangement and then dissociate to produce this new fragment, which is considered to generate after surmounting a few barriers including intra- and inter-molecular methyl migrations by the aid of theoretical calculations. The appearance energy of this new fragment is measured as 11.55 ± 0.05 eV by scanning photoionization efficiency curve. While the signal intensity of fragment m/z = 61 starts to increase, the fragments m/z = 47 and 77 tend to slowly incline around 11.55 eV photon energy. This suggests that the additional fragment channels other than (C 2 H 5 OH) ⋅ H + and CH 2 O ⋅ (C 2 H 5 OH)H + have also been opened, which consume some dimer cations. The present report provides a clear description of the photoionization and dissociation processes of the ethanol dimer in the range of the photon energy 12-15 eV.
研究领域:
化学物理学
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理论计算化学
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PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 5
·124863
·
IF 7.5
Bingliang Zhang,Cong Wang,Fuyao Tong,Meixue Chen,Xiaojuan Liu,Xifeng Shi
UV-based advanced oxidation processes (UV-AOPs) show great potential for municipal wastewater advanced treatment. Although chlor(am)ine-based UV-AOPs have been widely investigated, discrepancies in chlorinated byproduct (Cl-BP) formation and biotoxicity risks among UV/chlorine (UV/Cl 2 ), UV/chloramine (UV/NH 2 Cl), vacuum ultraviolet/ultraviolet/chlorine (VUV/UV/Cl 2 ), and VUV/UV/chloramine (VUV/UV/NH 2 Cl) processes for municipal secondary effluent treatment remain poorly understood. Herein, gas chromatography, Fourier transform ion cyclotron resonance mass spectrometry, and Vibrio fischeri were employed to reveal the formation characteristics of Cl-BPs and acute toxicity variations during these treatments. The results indicated that UV/Cl 2 process produced the highest levels of total organic chlorine (TOCl), known Cl-BPs, calculated cytotoxicity, and acute toxicity. In contrast, VUV/UV/NH 2 Cl treatment exhibited the lowest values for these parameters, with reductions of 61.3%, 96.3%, 99.7%, and 28.0% relative to UV/Cl 2 system. UV/Cl 2 treatment yielded the largest number of unknown Cl-BPs with high saturation, while VUV/UV/NH 2 Cl process generated the fewest Cl-BPs, consisting of more unsaturated CHONCl compounds. Mass difference analysis revealed that Cl 2 -based AOPs had the most precursors and precursor-product pairs, with oxygenation, chlorine substitution and addition as the principal reactions, whereas NH 2 Cl-based ones were dominated by nitrogen-related reactions. Considering Cl-BP and biotoxicity mitigation, VUV/UV/NH 2 Cl process emerges as the most promising technology for advanced treatment of municipal secondary effluent. Overall, this study provides fundamental insights and technological guidance for applying (VUV/)UV-AOPs to real municipal wastewater.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 57
·120590-120604
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IF 5.8
Lu Wen,Ren Songyu,Zhang Yanyu,Wen Ximeng,Zhang Zhongguo,Wang Aimin
A comparative study on the mineralization of antibiotic trimethoprim (TMP) in neutral medium was investigated by applying irradiation with five types of ultraviolet lamps. Among these lamps, the whole envelope of one lamp contained ordinary quartz, which could only transmit ultraviolet-C (UVC) light. For the other four lamps, approximately one tenth, a quarter, a half, and full of envelopes were comprised of high-purity synthetic quartz, which can transmit both vacuum ultraviolet (VUV) and UVC light. TMP decay was well fitted to pseudo-first-order reaction kinetics and occurred more quickly as the VUV intensity increased. Poor mineralization was achieved in the absence of VUV light, whereas the mineralization efficiency was also enhanced with increasing VUV intensity. The presence of hydroxyl radicals ( • OH), superoxide radicals (O 2 •− ) and singlet oxygen ( 1 O 2 ) during VUV photolysis of water was confirmed by electron paramagnetic resonance (EPR) analysis. Appropriate radical quenching experiments and fluorescent molecular probe detection provided the evidence that • OH played a significant role in TMP mineralization. Higher VUV intensity favored the generation of H 2 O 2 and • OH. The evolution of NH 4 + and NO 3 − as well as carboxylic acids (formic, acetic, oxalic, and oxamic acids) released in the treated solution were quantified. Ten aromatic intermediates were also identified by UPLC-QTOF-MS. Thereby, a plausible reaction sequence for TMP mineralization in VUV/UVC photolysis was finally proposed. Graphical Abstract
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高影响因子
Micromachines
·
2022
·Vol. 13
·期 9
·1372
·
IF 3.523
Jiandong Hao,Ling Li,Peng Gao,Xiangqian Jiang,Chuncheng Ban,Ningqiang Shi
The fabrication process of vacuum ultraviolet (VUV) detectors based on traditional semiconductor materials is complex and costly. The new generation of wide-bandgap semiconductor materials greatly reduce the fabrication cost of the entire VUV detector. We use the chemical vapor deposition (CVD) method to grow boron nitride nanoribbons (BNNRs) for VUV detectors. Morphological and compositional characterization of the BNNRs was tested. VUV detector based on BNNRs exhibits strong response to VUV light with wavelengths as short as 185 nm. The photo–dark current ratio (PDCR) of this detector is 272.43, the responsivity is 0.47 nA/W, and the rise time and fall time are 0.3 s and 0.6 s. The response speed is faster than the same type of BN-based VUV detectors. This paper offers more opportunities for high-performance and low-cost VUV detectors made of wide-bandgap semiconductor materials in the future.
研究领域:
材料科学
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纳米技术
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光电子学
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半导体器件
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DOI
高影响因子
WATER ENVIRONMENT RESEARCH
·
2020
·Vol. 93
·期 3
·455-463
·
IF 1.369
Yuanhao Li,Qiufeng Lin,Cong Li,Zijian Weiguo,Luo Xu,Kejia Zhang
Perfluorooctanoic acid (PFOA) is one kind of persistent organic pollutants that is often detected in water. In recent years, the effective degradation technologies of PFOA have attracted widespread attentions. Thus, in this study, the defluorination efficiency of PFOA in different systems (i.e., ultraviolet (UV), vacuum ultraviolet (VUV), vacuum ultraviolet/persulfate (VUV/PS) and vacuum ultraviolet/residual chlorine (VUV/RC)) was evaluated. Moreover, the different impact factors (i.e., the initial concentrations of persulfate and PFOA, temperature, anions, and initial pH values) on PFOA degradation by VUV/PS system were investigated. The results showed that VUV system was more effective than UV system for PFOA defluorination. VUV system combined with persulfate would further enhance the defluorination efficiency while residual chlorine would decrease it. In VUV/PS system, the defluorination efficiency of PFOA was the best as the molar ratio of PFOA and persulfate at 1:60. Moreover, higher temperature, lower initial PFOA concentration, and acid condition were favorable for the defluorination of PFOA. Under the different influence factors, the defluorination efficiency of PFOA fitted well to the first-order reaction kinetic model. When the temperature was range from 20°C to 40°C, the value of activation energy was 8.73 kJ/mol. Besides, the inhibition effect of three kinds of anions on PFOA defluorination followed the order: > Cl − > . Practitioner points The defluorination efficiency of perfluorooctanoic acid (PFOA) in water by different VUV systems was compared. VUV system is more effective than UV system for PFOA defluorination. Persulfate will enhance the defluorination efficiency by VUV system. Hypochlorite will decrease the defluorination efficiency by VUV system.
研究领域:
环境科学
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水处理
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污染物降解
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PubMed
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Huimei Pan,Yuanxi Huang,Juan Li,Boqiang Li,Yang Yang,Baiyang Chen,Rongshu Zhu
Haloacetaldehydes (HALs) are the third largest disinfection by-product (DBP) ubiquitously detected in finished drinking water and have relatively higher toxicity than currently regulated DBPs. To efficiently alleviate them, this study investigated a green, chemical-free technology by using ultraviolet/vacuum ultraviolet (UV/VUV) on degrading three refractory chlorinated HALs (Cl-HALs). The results indicate that the rates of Cl-HALs decomposition in tap water irradiated by UV/VUV were 23–70 times higher than those irradiated by UV, proving that VUV instead of UV played the key role in degrading Cl-HALs. Increasing Cl-HALs dosage, pH, and dissolved oxygen (DO) all decreased the Cl-HALs degradations significantly, and the rates in tap water were apparently lower than those in ultrapure water. Unlike previous studies, this study proved that both oxidation and reduction were present during the VUV process. Photooxidation via oxidative radicals like •OH mineralized Cl-HALs, leading to substantial drops of total organic carbon ; photoreduction via reductive radicals like •H dehalogenated Cl-HALs, resulting in formation of considerable intermediate organics (e.g., formic acid and acetic acid). No matter what pathway, the mass balances of chlorine were always maintained, meaning that dehalogenation occurred instantaneously rather than sequentially. Although the overall photodegradation rates dropped with rising pH and DO, photoreduction was increased with rising pH while photooxidation was elevated with rising DO. The results hence provide insights to better understand the VUV technology in controlling micropollutants in water.
研究领域:
环境科学
·
水处理技术
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DOI
PubMed
高影响因子
Water Supply
·
2020
·Vol. 20
·期 8
·3615-3624
·
IF 0.9
Gu Yurong,Dong Zijun,Zhang Xi,Han Qi,Li Yongbing
Perfluorosulfonic acids (PFSAs) have attracted increasing attention due to their global distribution, high chemical stability and persistence. As a powerful reductant, hydrated electron ( ) shows extraordinary reactivity towards halogenated organic substances like PFSAs. In this study, -based photo-decomposition of perfluorohexane sulfonate (PFHxS) in a VUV/sulfite system was investigated. The k obs of PFHxS decomposition in the studied system was 0.0049 ± 0.0005 min −1 , which was 24.5-fold faster than that in a sole VUV system. It was demonstrated that was the main reactive species responsible for PFHxS decomposition. PFHxS decomposition kinetics were accelerated at higher initial solution pH and sulfite dosage, but were restrained when higher initial PFHxS concentration was introduced. Co-existence of chloride showed slight enhancement of PFHxS decomposition, whereas nitrate and bicarbonate suppressed PFHxS decomposition. Accompanying PFHxS decomposition, short chain perfluorocarboxylic acids (PFCAs) were detected as main intermediate products. PFHxS decomposition started with C-S bond fracture, followed by perfluoroalkyl radical hydrolysis reactions and perfluorohexanoic acid (PFHxA) formation. Afterwards, PFHxA was defluorinated by stepwise loss of CF 2 units to generate other short chain PFCAs.
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高影响因子
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