JOURNAL OF HAZARDOUS MATERIALS
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2019
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IF 7.65
Dong Wen,Wentao Li,Jinrong Lv,Zhimin Qiang,Mengkai Li
This study investigated methylene blue (MB) degradation by the vacuum-ultraviolet/ultraviolet/persulfate (VUV/UV/PS) process using a mini-fluidic VUV/UV photoreaction system. Results show that MB degradation by the VUV/UV/PS process was significantly higher than that of the conventional UV/PS process, as the VUV photolysis of H 2 O and PS generated more reactive oxygen species (ROSs). HO • and SO 4 •− , identified as the main ROSs, were mostly consumed by dissolved organic carbon and Cl ‒ in real waters, respectively. Additionally, the impacts of solution pH and the concentrations of PS, humic acid, and inorganic ions (HCO 3 ‒ , Cl ‒ , NO 3 ‒ , SO 4 2‒ , Fe(II), and Fe(III)) were systematically evaluated. The solution pH significantly affected the photon absorption distributions, as well as the contributions of photolysis and oxidation to MB degradation, resulting in different variations in the degradation rate constant and total organic carbon removal ratio with increasing solution pH. At all tested pH levels (3.0–11.0), particularly under acidic conditions, HO and SO 4 − were two predominant contributors to MB degradation, while VUV and UV photolysis contributed more when the solution pH increased. This study provides a highly efficient process for organic pollutant removal, which could be applied in water treatment.
研究领域:
环境科学
·
水处理工程
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
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
Journal of Environmental Chemical Engineering
·
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
Sustainability
·
2025
·Vol. 17
·期 21
·9882
·
IF 3.3
Yi-Fan Zhang,Hong-Wei Xu,Nan Huang
The non-oxidizing antimicrobial 2-Methyl-4-Isothiazolin-3-one (MIT) poses a significant environmental risk given its frequent detection in municipal wastewater. This study showed that the combination of Vacuum UV/UV (VUV/UV) and persulfate (PDS) efficiently achieved the rapid transformation and removal of 10 μM MIT within 90 s, which is much faster than UV, UV/PDS, and VUV/UV. Increasing the PDS dosage improved MIT degradation, whereas changes in pH between 4 and 10 had little effect. Radical quenching experiments showed that 93% of the MIT oxidation was attributable to the hydroxyl radical (•OH) and the sulfate radical (SO4•−). SO4•−and •OH at concentrations of 8.6 × 10−12M and 1.5 × 10−12M accounted for 32% and 61% of the MIT degradation, respectively, and the greater contribution of •OH was attributed to its higher reaction rate constant with MIT compared to SO4•−. Sulfate had a negligible impact on the radical concentrations. Chloride (1 mM) reduced the SO4•−and •OH concentrations by 61% and 27%, respectively. And the SO4•−contribution to MIT degradation fell to 19%. Nitrate (5 mM) readily quenched •OH but minimally affected SO4•−. The •OH concentration decreased by 79%, reducing its contribution to 27%. Bicarbonate/carbonate (5 mM) simultaneously reduced the SO4•−and •OH by 26–30% and had little effect on their contributions. Because of the quenching effect of organic matter and inorganic anions on radicals, secondary effluent inhibited the degradation of MIT. After a 120 s treatment, the total organic carbon, UV254, and fluorescence regional integration were reduced by 5%, 8%, and 17–24%, respectively. This study provides a quantitative analysis of how inorganic ions alter the concentrations and contributions of •OH and SO4•−, elucidating the MIT removal mechanisms in VUV/UV/PDS for sustainable wastewater reclamation.
研究领域:
环境科学
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水处理技术
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高级氧化工艺
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污染物降解
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自由基化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）