CHEMOSPHERE
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2022
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IF 8.943
Zhangbin Pan,Zhenqi Du,Junqi Jia,Aiguo Lin,Yongqiang Wang,Wuchang Song,Shaohua Sun,Hongbo Wang,Ruibao Jia,Lian Hou
2,6-dichloro-1,4-benzoquinone (DCBQ), a typical representative of Halobenzoquinones, is an emerging aromatic disinfection by-product (DBP) with high toxicity and carcinogenicity , generated commonly through the chlorination in the drinking water disinfection process while there is still a lack of research on its removal. In this study, the effects of ultraviolet-based advanced oxidation processes (UV-AOPs) on the degradation of DCBQ were evaluated. The results showed that UV-AOPs are effective in degrading DCBQ. The removal of DCBQ by UV/H 2 O 2 /O 3 was more significant than by UV/H 2 O 2 or UV/O 3, achieving a 96.7% removal rate at both the O 3 and H 2 O 2 doses of 1 mg/L. The results also indicated the alkaline and weakly acidic environments could facilitate the degradation of DCBQ, inorganic anions could inhibit DCBQ degradation and the degree of inhibition increased as the matrix concentration increased. The degradation of DCBQ was inhibited more by the CO 3 2− than the other matrix components, such as Cl − and NO 3 − . It was shown by the density functional theory simulations and the ultrahigh-performance liquid chromatography (UPLC) - Orbitrap mass spectra that the electrons in DCBQ are mainly on the chlorine atom connected to the carboatomic ring and that OH• can attack the chlorine atom to cause de-chlorination. The DCBQ degradation pathway may involve the oxidation of DCBQ to 3-hydroxy-2,6-DCBQ (HO–DCBQ) and 3,5-dichloro-1,2,4-pyrogallol, the further degradation of intermediate products by OH• to dechlorinated forms of HO–DCBQ and DCBQ.
研究领域:
环境科学
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水处理工程
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化学
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
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2025
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IF 6.7
Qianqian Ding,Zhaoyang Wang,Hong Sun,Yuxing Guo,Xinyang Bai
Microplastics (MPs) are a widespread emerging pollutant that can harm human health through the food chain or direct ingestion. Therefore, it is of great significance to study the transformation of MPs in water. The mechanism of changes of 3 kinds of MPs under different environmental conditions was studied by Ultraviolet-Advanced oxidation combined process (UV-AOPs). PARAFAC, SEM, FTIR, TOC and LPSA were used to explore the change mechanism. The results showed that the 3 MPs exhibited different degrees of fragmentation and folding with reaction time, temperature and pH. When the reaction time T = 60 min, pH = 4, t = 30 °C, V = 15 V, the aging is the most obvious, and the functional groups such as -CH 2 , C O and -CH all change. In addition, the particle sizes of the three kinds of MPs after the reaction were all reduced by an average of 18 % compared with the initial ones. At the same time, a certain amount of DOM is also released, and the main components are aromatic proteins. This study revealed the aging effects of different types of MPs in UV-AOPs process, explored the surface morphological changes of MPs and the release of organic matter, in order to provide more reference and support data for the environmental behavior of MPs.
研究领域:
环境科学
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污染生态学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
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2022
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IF 13.4
Guangqiang Cai,Tongzhou Liu,Jinsong Zhang,Haoran Song,Qijun Jiang,Chang Zhou
Spore forming bacteria (SFB) are strongly chlorine resistant. Their presence in drinking water may cause diseases and pose threat to public health. Three SFB strains, i.e. Bacillus alvei, Bacillus cereus , and Lysinibacillus fusiformis , were isolated and identified from the finished water of a drinking water treatment plant where bacteria colonies occasionally reached the limit value. Due to their chlorine resistance, a SFB control strategy coupling pre-oxidation, coagulation sedimentation, and UV-AOPs inactivation in water treatment process was studied in lab scale. Five minutes pre-oxidation treatment by applying Cl 2 and ClO 2 induced remarkable spore transformation. Longer pre-oxidation exposure time didn't have apparent improvement. Cl 2 and ClO 2 dosages of 0.9 mg/L and 0.5 mg/L were suggested, respectively. The formed spores can be efficiently removed by the following coagulation sedimentation treatment. At a suggested dosage combination of 20 mg/L PAC and 0.08 mg/L PAM, spore removal efficiency reached about 3.15-lg. Comparing to applying sole UV irradiation, enhanced UV inactivation by adding 0.1 mM H 2 O 2 , or Cl 2 , or peroxymonosulfate (PMS) substantially improved the inactivation of the most chlorine resistant SFB strain, Lysinibacillus fusiformis . UV-AOPs stably achieved 2-lg inactivation rate at UV dosage of 40 mJ/cm 2 . UV/H 2 O 2 , UV/Cl 2 and UV/PMS inactivation kinetically enhanced 1.20 times, 1.36 times and 1.91 times over sole UV irradiation. Intracellular DNA and ATP leakages were detected, and remarkable damages of Lysinibacillus fusiformis cells’ surface and ultrastructure were observed. These findings evidenced cell wall and cell membrane destructions, guaranteeing substantial SFB cells inactivation. This study was carried out based on three SFB strains isolated from a finished water, and common engineering practical operations. By providing engineeringly relevant references, the outcomes obtained would be helpful for dealing with SFB outbreak risk in drinking water treatment .
研究领域:
微生物学
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环境工程
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公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
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2024
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IF 11.4
Qing Bai,Qian-Yuan Wu,Bei Ye,Yun-Peng Wu,Ju-Won Lee,Min-Yong Lee,Wen-Long Wang
The KrCl* excimer lamp (UV222) is a promising alternative of low-pressure mercury lamp (UV254) for UV-based advanced oxidation processes (UV-AOPs), because it is mercury-free and has high photon energy. But there lacks a comprehensive assessment of UV222-AOPs based on different radicals. Herein, the properties (e.g., oxidant decay and innate radical quantum yield), and micropollutant degradation, were comprehensively studied for representative oxidants (i.e., hydrogen peroxide, persulfate (PDS), monochloramine, and free active chlorine (FAC)) under UV222 irradiation. UV222 outperformed UV254 for the activation of oxidants with 2.6-14.4 times fluence-based kinetic constant ( k F ). The main reason of enhanced activation varied with oxidants: higher UV absorption for H 2 O 2 , higher innate quantum yield for monochloramine and FAC, and both reasons for PDS. Overall, PDS was the optimum oxidant under UV222 for the degradation of 8 representative micropollutants because of effective promotion of radical formation, as confirmed by radical competitive kinetics and modeling simulations. In real water, UV222/PDS still show advantages than UV254/PDS in terms of micropollutant elimination efficacy (3.2-5.3 times) and energy consumption (33.9%-57.6% lower) though it was more inhibited by water constituents via competing for UV222 photons. This study fills gaps in photochemistry knowledge and will facilitate engineering practice of UV222-AOPs.
研究领域:
环境科学
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化学工程
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光化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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