Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Pengchao Xie,Yujia Zou,Shan Jiang,Zongping Wang,Jingwen Wang,Li Zhang,Siyang Yue,Xiaonan Feng
Good degradation of β -blocker propranolol (PrP) in the VUV/UV 254 system was achieved in both pure water and realistic water. Both hydroxyl radical (HO • ) and UV 254 photolysis have been evidenced to contribute to PrP degradation in the VUV/UV 254 system. A kinetic model by including both HO • and UV 254 photolysis was successfully applied to predict the observed rate constant ( k obs ) of PrP degradation in the VUV/UV 254 system under different conditions. Elevating initial PrP concentration would reduce the steady-state concentration of HO • , as a result to decreasing the k obs of PrP degradation. While elevating reaction temperature can significantly accelerate PrP degradation. The degradation of PrP in the VUV/UV 254 system was little affected by the variation of reaction pH. HCO 3 − /CO 3 2− , humic acid (HA) and Cl − significantly inhibit PrP degradation in the VUV/UV 254 system. The PrP degradation pathways initiated with hydroxylation and cleavage of side chain were proposed. Although some intermediate products containing higher acute toxicity than PrP were produced in the initial phase of PrP degradation, they could be further oxidized to low toxic products in the system. This study provides that VUV/UV 254 would be a good advanced oxidation process for the treatment of β -blockers in aquatic environment.
研究领域:
环境科学
·
水处理工程
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DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Yudan Liu,Jingke Wu,Nanchunxiao Cheng,Pengfei Gan,Yunyi Li,Wen Liu,Jiangyu Ye,Meiping Tong,Jialiang Liang
Vacuum ultraviolet (VUV) based advanced oxidation processes (AOPs) recently attracted widespread interests. However, the role of UV 185 in VUV is only considered to be generating a series of active species, while the effect of photoexcitation has long been overlooked. In this work, the role of UV 185 induced high-energy excited state for the dephosphorization of organophosphorus pesticides was studied using malathion as a model. Results showed malathion degradation was highly related to radical yield, while its dephosphorization was not. It was UV 185 rather than UV 254 or radical yield that was responsible for malathion dephosphorization by VUV/persulfate. DFT calculation results demonstrated that the polarity of P-S bond was further increased during UV 185 excitation, favoring dephosphorization while UV 254 did not. The conclusion was further supported by degradation path identification. Moreover, despite the fact that anions (Cl - , SO 4 2 - and NO 3 - ) considerably affected radical yield, only Cl - and NO 3 - with high molar extinction coefficient at 185 nm significantly affected dephosphorization. This study shed light on the crucial role of excited states in VUV based AOPs and provided a new idea for the development of mineralization technology of organophosphorus pesticides.
研究领域:
环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Eslam Ibrahim El-Aswar,Yu Lei,Zhimin Qiang,Yanyan Huang,Gholamreza Moussavi,Mengkai Li
The vacuum-ultraviolet/ultraviolet/air micro-nano bubble (i.e., VUV/UV/MNB) process is a promising solution for wastewater treatment with high-efficiency and chemical-free advantages. However, the influence of surfactants, a common component wide-spread in wastewater on VUV/UV/MNB efficiency remains unknown. This study investigated the overlooked role of surfactants in enhancing the degradation of emerging contaminants in the VUV/UV/MNB process, using carbamazepine (CBZ) as a model contaminant. The addition of surfactants increased the CBZ degradation rate by at least 62 %, compared to 50 % without them. The anionic surfactant, sodium dodecylbenzene sulfate (SDBS), exhibited the highest promoting effect, while the cationic surfactant, dodecyl trimethyl ammonium bromide, exhibited the least. Notably, the enhancement plateaued at an optimal [SDBS] 0 , beyond which competition between HO • and SDBS hindered further degradation. The 75.8 % degradation enhancement with SDBS, compared to 50.8 % for a non-surfactant, was attributed to its amphiphilicity and adsorption capability, which increased CBZ interfacial concentration. Furthermore, SDBS showed enhanced MNBs stabilization, evidenced by a smaller reduction in CBZ degradation (8.6 %) compared to non-surfactant (23.9 %) in the intermittent bubbling mode. Key surfactant properties, including the surface activity, diffusion coefficient, and saturated equilibrium surface excess, were found to govern these reaction mechanisms. Besides, the addition of SDBS increased the relative contribution of interfacial reactions from an average of 55.9 % to 70.1 %, representing a 14.2 % enhancement in interfacial reaction dominance compared with the SDBS-free system. This study demonstrates the potential of VUV/UV/MNB process for effectively treating wastewaters enriched with surfactants.
研究领域:
环境科学
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水处理技术
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高级氧化过程
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化学工程
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2019
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IF 7.913
Liangchen Long,Yinan Bu,Baiyang Chen,Rehan Sadiq
To discover an applicable technology for urea abatement from swimming pool water (SPW), this study compared the performances of seven ultraviolet (UV)-based technologies on urea removal, including UV alone, UV coupled with hydrogen peroxide (UV/H 2 O 2 ), sulfite (UV/Na 2 SO 3 ), potassium persulfate (UV/K 2 S 2 O 8 ), a combination of UV and vacuum UV (UV/VUV), and UV/VUV in tandem with either H 2 O 2 (VUV/H 2 O 2 ) or potassium persulfate (VUV/K 2 S 2 O 8 ). Among them, UV and UV/Na 2 SO 3 showed little removal ability, and UV/H 2 O 2 removed only 12.8% of urea within 3-h experiments, while UV/VUV degraded 71.7% of urea without introducing substantial total dissolved solids (TDS). Therefore, UV/VUV was considered as a promising technology for further exploration. In comparison, although UV/K 2 S 2 O 8 exhibited higher urea removal than UV/VUV, it caused dramatic increases of TDS, which made the regulatory threshold for the TDS increment difficult to maintain. Within UV/VUV studies, some common components in SPW (e.g., cyanuric acid , humic acid , nitrate, and bicarbonate) inhibited the removal process, whereas chloride and sulfate facilitated it, while free chlorine at doses ≤ 3 mg-Cl 2 /L and pH levels from 6.8 to 8.0 imposed little impact on urea degradation. Overall, UV/VUV degraded 40.0% and 22.2% of urea from tap water and SPW, respectively; both were lower than the efficiency observed in ultrapure water. As for reaction byproducts, urea phototransformation via UV/VUV yielded nitrate and ammonia as the key products with the mass balance of nitrogen element being met. However, the contents of organic carbon decreased at a rate slightly lower than urea degradation, suggesting that urea was mostly mineralized and slightly converted to unknown organic compounds. The results hence demonstrate that UV/VUV is an effective alternative for urea removal from SPW.
研究领域:
环境科学
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水处理工程
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2026
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IF 6.6
Zhitao Xu,Zhiping Cao,Li Li,Zhiwei Zhao,Zhijie Liang,Kexiang Qu,Mengnan Li,Yexuan He
Per - and polyfluoroalkyl substances (PFAS) are environmentally persistent, and conventional treatment methods often suffer from low degradation efficiency and high energy consumption. This study developed a vacuum ultraviolet/sulfite (VUV/SO 3 2− ) advanced reduction process to degrade perfluorooctanoic acid (PFOA), a representative PFAS. Under optimized conditions, the system achieved a defluorination efficiency of 75.68% and a degradation rate exceeding 95% within 2 h. The degradation mechanism is driven by the synergistic action of hydrated electrons (e aq − ) from VUV photolysis and hydroxyl radicals ( • OH) from sulfite activation, which promote stepwise cleavage of terminal C F bonds. Computational results further support that electron attachment at the terminal C F sites initiates defluorination. The system exhibits strong resistance to Cl − and PO 4 3− , while CO 3 2− , NO 3 − , and humic acid inhibit degradation by scavenging active species. The electrical energy per order (EE/O) was measured at 8.89 kWh/ m 3 , significantly lower than traditional UV-based systems. Additionally, the proposed “Energy Consumption per unit Defluorination” metric highlights the energy efficiency of fluoride removal, demonstrating the potential of the VUV/SO 3 2− process for practical PFAS remediation.
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Hang Li,Yanling Yang,Jiawei Ren,Zhiwei Zhou,Xing Li,Yuankun Liu,Jianyong Feng
Pre-ozonation is often used as an effective method to assist coagulation in removing organic contaminants . In this study, a new process that combining ozone (O 3 ) with vacuum ultraviolet (VUV/UV) process (VUV/UV/O 3 ) is investigated to enhance the removal of organic matters in greywater from public buildings or household. The influence of organic characteristics (molecular weight distribution, hydrophobicity , and fluorescence) in greywater on VUV/UV/O 3 enhanced coagulation has not been fully studied. Herein, organic matters of greywater were separated and classified, and fates of organic fractions by VUV/UV/O 3 enhanced coagulation were clarified. Greywater contains tryptophan-like and tyrosine-like proteins, and terrestrially derived humic-like substances. The highest UV 254 , LAS , DOC and COD Cr removal efficiency from greywater could reach up to 47.54%, 58.92%, 17.96% and 15.76% in VUV/UV/O 3 enhanced coagulation, respectively. The removal efficiency of tryptophan-like and tyrosine-like in filtrates of varied molecular weight ranges by VUV/UV/O 3 enhanced coagulation was 93.59%–98.13% and 89.86%–95.53%, respectively. VUV/UV/O 3 enhanced coagulation was effective for the removal of bio-polymers, humic substances and low molecular weight acid ≤ 30 kDa, while it was insignificant for that of 0.22 µm - 100 kDa. Particle size of flocs increased significantly in filtrates obtained from increasing membrane pore size, indicating that macromolecular organic matter was more likely to form flocs. Finally, the VUV/UV/O 3 could improve coagulation on the removal of varied organic pollutants and improve sedimentation by changing the flaky flocs to dense ones. Therefore, the results demonstrate VUV/UV/O 3 is an effective pre-oxidation method to enhance the effect of coagulation on greywater treatment.
研究领域:
环境科学
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水处理工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Xiao-Yan Fan,Shi-Long Xu,Xing Li,Zhi-Wei Zhou,Yu-Xi Gao,Jun-Ru Zhao,Zhong-Xing Zhang
Antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in secondary effluent from wastewater treatment plants (WWTPs) have a size-fractionated character and conventional processes have difficulties in removing ARGs and MGEs. Therefore, this study aimed to explore the removal efficiency, removal mechanism and regeneration potential of size-fractionated ARGs and MGEs by vacuum ultraviolet (VUV)-activated peroxymonosulfate (PMS) and ascertain their potential hosts in secondary effluent. The proportion of particle-associated (PA)-ARGs and PA-MGEs was 85.07 %, followed by free-living (FL) fraction (14.91 %) and cell-free (CF) fraction (0.02 %). More than 95.00 %∼99.99 % of ARGs and MGEs in PA- and CF- fractions were removed by VUV/PMS, but the average removal efficiency of FL-ARGs and FL-MGEs was 66.15 %. Compared to the regeneration potential of PA- and CF-ARGs and MGEs (0.02 < C/C 0 < 5.27), the regeneration occurred mainly in FL-ARGs and FL-MGEs (0.08 < C/C 0 < 24.06). ·OH was the dominant radical (16.810 × 10 -6 mol/L) in VUV/PMS for the removal of size-fractionated ARGs and MGEs from the secondary effluent, while SO 4 - · (4.478 × 10 -6 mol/L) played a supporting role in the system based on the quenching experiment, electron paramagnetic resonance spectrometer and probe experiments. Based on full-scale classification, conditionally rare or abundant taxa (CRAT) were the core potential hosts in PA-, FL- and CF- fractions, while rare taxa (RT) and conditionally rare taxa (CRT) potential hosts were more diverse in the three fractions. This study suggests that VUV/PMS can effectively remove size-fractionated ARGs and MGEs from secondary effluent and thereby obviously reduce their dissemination risk to receiving water bodies, providing technical support for the engineering application of VUV/PMS in full-scale WWTPs .
研究领域:
环境科学
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微生物学
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产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Yining Dai,Yanling Yang,Xing Li,Nan Wang,Zhiwei Zhou,Jianyong Feng,Yongwang Liu,Hang Li
Reusing treated greywater indoors in buildings is an advanced strategy to increase the utilization of limited water resources , but currently there is a lack of feasible technologies for efficiently purifying greywater indoors. In this study, we construct the heterogeneous TiO 2 -stainless steel mesh (SSM) interface with photocatalytic degradation of sodium dodecylbenzene sulfonate (SDBS) by under vacuum ultraviolet (VUV) irradiation. At the initial SDBS of 10 mg/L, the degradation rates of SDBS with UV/TiO 2 -SSM and VUV/TiO 2 -SSM process were 53 % and 74 % respectively within 50 min. The results of specific scavengers experiments and EPR analysis revealed that the ·OH, h + and direct photolysis contributed to SDBS degradation and mineralization . The degradation rate of SDBS in VUV/TiO 2 -SSM process was higher at weak acid or weak alkali conditions, while the performance of UV/TiO 2 -SSM process was better at alkaline conditions. Both Cl − and HCO 3 − could inhibit SDBS degradation, while SO 4 2− slightly promoted the degradation. Active oxygen species mainly degrade SDBS in two ways: by attacking the α carbon, β carbon, or branched chain carbon on the alkane chain ; or by attacking the adjacent carbon on the alkane chain, resulting in the formation of three branch forms of products. The toxicity of the intermediate products shows a decreasing or stable trend. The experiment shows that UV or VUV photocatalytic TiO 2 -SSM has a good prospect of removing anionic surfactant in the real greywater. This study provides strategies for the development and design of indoor water reuse technologies and devices in buildings.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2017
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IF 2.536
Pengchao Wang,Yongjun Hu,Huaqi Zhan,Jiaxin Chen,Shan Jin,Wentao Song,Yujian Li
Tetrahydrofurfuryl alcohol (THFA, C 5 H 10 O 2 ) is a close chemical analog of the sugar rings present in the phosphate-deoxyribose backbone structure of the nucleic acids . In present report, the infrared (IR) spectra of the size-selected THFA monomer and its dimer have been investigated in a pulsed supersonic jet using infrared-vacuum ultraviolet (VUV) ionization. Herein, the laser light at 118 nm wavelength served as the source of “soft” ionization in a time-of-flight mass spectrometer. The IR features for the monomers located at 3622 cm − 1 can be assigned to the intramolecular hydrogen bonding stretch vibrations mainly referring to A and C conformers . Compared with the monomer, however, characteristic peaks for the dimer centered at 3415 and 3453 cm − 1 , red shifted 207 and 169 cm − 1 , respectively, were associated with the intermolecular hydrogen bonding stretch vibrations. Combined with the quantum-chemical calculations, the dimer in the gas phase preferred cyclic AC conformer stabled by forming two strong intermolecular hydrogen bonds, which shown the high hydrogen bond selectivity in the cluster. The conclusions drawn from the role played in the conformational flexibility by the hydroxyl and ether groups may be extended to other biomolecules.
研究领域:
物理化学
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光谱学
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分子团簇
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气相化学
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生物物理化学
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DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
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2017
·Vol. 146
·期 13
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IF 2.965
Zhan Huaqi,Hu Yongjun,Wang Pengchao,Chen Jiaxin
Tetrahydropyran-2-methanol (THPM) is a typical alcohol containing a six-member cyclic ether, which can be considered as the model molecule of cyclic sugar. Herein, vacuum ultraviolet (VUV) photodissociation spectroscopy is employed to study fragmentation pathways and infrared (IR) plus VUV photoionization spectroscopy to investigate the structures of neutral THPM and its clusters with the size up to the trimer. Qualitative structural assignments are confirmed for the neutral species and ions based on MP2/aug-cc-pVTZ and ωB97X-D/cc-pVTZ calculations. The fragment cations at m/z = 84, 85, and 98 arise by the losing of CH 2 OH, CH 3 OH, and H 2 O from the monomer, respectively, as a result of C–C bond and C–O bond dissociation under the VUV (118 nm) radiation. It is found that the loss of CH 3 OH and H 2 O involves hydrogen transfer from the CH 2 group to the dissociating CH 2 and OH groups. Comparing the observed and calculated spectra of the monomer THPM, it suggests that the conformer containing a chair tetrahydropyran ring and an intramolecular hydrogen bond would be dominantly survived in a supersonic beam. Moreover, the IR spectra of larger clusters n > 1 (n = 2, 3) show only the broad hydrogen bonded OH stretch mode, and thus these larger clusters would form a closed-cyclic structure, where all OH groups are participating in hydrogen bonding. Partially the CH stretch positions of THPM clusters do not change significantly with the increasing of cluster size, thus the CH and CH 2 groups are not involved in H-bonding interactions.
研究领域:
物理化学
·
分子光谱学
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DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2021
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IF 5.541
Yongdi He,Jinou Song,Yuan Zhuang,Jiuzhong Yang,Zhongwei Meng,Qiang Xu
An experimental study of 1-nitropropane (1-NP) pyrolysis was performed in a flow reactor at low pressure (4.0 kPa) in the temperature range of 623–973 K. The pyrolysis species was detected with the tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry (MBMS). Species from m/z = 15–87 were identified from near-threshold photoionization efficiency (PIE) spectra, such as radicals of CH 3 , C 2 H 5 , C 3 H 5 and C 3 H 7 ; isomers of C 2 H 4 O (ethenol and acetaldehyde), C 3 H 6 O (acetone and propanal), C 4 H 10 (butane and isobutane), HNC (hydrogen isocyanide), HCN (hydrogen cyanide)), C 3 H 5 N (ethyl isocyanide and species with unidentified structure) and C 3 H 5 NO (methoxyacetonitrile and species with unidentified structure). Their mole fraction profiles were evaluated at different temperature. Based on the mole fractions of species measured at the minimum temperature of 1-NP pyrolysis, some new channels of 1-NP primary pyrolysis were speculated, such as the channels involving O-transfer from N to C-atoms in different positions, deoxygenation, dehydrogenation and OH-abstraction. Based on the mechanisms proposed in the literature, the species produced from secondary or subsequent reactions were also discussed. These results are valuable to a further quantum mechanical calculation for a better understanding of 1-NP chemistry.
研究领域:
化学动力学
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物理化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Qi Zhang,Lei Wang,Baiyang Chen,Yi Chen,Jun Ma
Understanding ultraviolet photolysis induced by low pressure mercury lamp that emits both 254 nm ultraviolet (UV 254 ) and 185 nm vacuum UV (VUV 185 ) is currently challenging due to the copresence of multiple direct and indirect photochemical processes involving a series of highly-reactive radicals. Herein we examined the formation and transformation of H 2 O 2 in water, which is both a precursor and a product of radicals, under various pH and dissolved oxygen (DO) conditions. The trends show that H 2 O 2 increased rapidly at early stage and then remained steady in DO-rich water or declined somewhat in DO-poor water, ultimately leading to higher steady-state H 2 O 2 in DO-rich water. The maximum H 2 O 2 contents nonetheless were similar among waters with different DO, suggesting that H 2 O 2 in this system was mostly generated by hydroxyl radical ( OH) recombination, which is an oxygen-independent H 2 O 2 formation pathway, rather than by reduced oxygen via hydrogen atom (H ) or hydrated electron (e aq − ), which is an oxygen-dependent pathway. Increasing pH (from 6.3 to 10.0) or bicarbonate dosage dramatically decreased H 2 O 2 formation too. Mathematically, the fates of H 2 O 2 as a function of pH, DO, and time were well modeled (R 2 ≥ 0.92), in which the rates of H 2 O 2 formation and destruction were greater in DO-poor water than those in DO-rich water. In addition, we found that the steady-state concentrations of OH used for degradation of p-chlorobenzoic acid, an OH probe, correlated well with the OH levels used for H 2 O 2 formation (R 2 = 0.98). These results hence may help better understand the UV/VUV process via H 2 O 2 evolutions.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
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