Frontiers of Environmental Science & Engineering
·
2025
·Vol. 19
·期 7
·1-16
·
IF 6.4
Yin Wenxuan,Sun Wenjun,Yuan Yongqin,Zhang Daoyi,Zhang Yuanna,Zheng Fengyi
UV/H 2 O 2 is commonly used to remove organic micropollutants and frequently paired with activated carbon for further removal of pollutants, addressing issues such as H 2 O 2 residuals, uncontrollable by-products, and energy consumption reduction. Here, we report the changes in the removal characteristics of organic contaminants during the operation of a pilot system based on UV/H 2 O 2 coupled granular activated carbon (GAC) after in situ biofilm formation to generate biologically activated carbon (BAC). We completed the screening of unknown organic matter and molecular-level chemical transformation of 100–1600 Da dissolved organic matter (DOM) using Fourier transform high-resolution mass spectrometry (FT-ICR MS). The FT-ICR MS results indicated that BAC differs from GAC in terms of DOM removal behavior and mechanisms. GAC primarily produces free radicals through synergistic residual H 2 O 2 to further oxidize and remove organics. Low molecular weight (LMW) organics undergo general molecular chemical changes but have modest removal effects. BAC considerably lowered the chemical variety of DOM and eliminated LMW organics through biodegradation and activated carbon adsorption. According to the study findings, UV/H 2 O 2 -BAC can more effectively compensate for the drawbacks of individual technologies than UV/H 2 O 2 -GAC, with superior removal efficiency of organic pollutants, no residual H 2 O 2 , controllable effluent products, and robust performance in real environmental matrices.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
Frontiers in Environmental Science
·
2021
·
IF 4.581
You Wen-Dan,Ye Pu,Yang Bin,Luo Xin,Fang Jie,Mai Zi-Tian,Sun Jian-Liang
Benzodiazepines are one group of psychoactive drugs widely detected in water environments, and their persistence during conventional wastewater treatment has raised great concerns. Here we investigated the degradation of 17 benzodiazepines in water by UV/H2O2 treatment. The results showed that the UV/H2O2 treatment significantly increased the degradation of 17 benzodiazepines in phosphate buffer solutions at pH 7.0. This can be attributed to the high reactivity of hydroxyl radicals (·OH) towards benzodiazepines with second-order rate constants of 3.48 × 109 M−1 s−1–2.44 × 1010 M−1 s−1. The degradation of alprazolam, a typical benzodiazepine, during the UV/H2O2 treatment was increased with the increasing H2O2 dosage. The solution pH influenced the alprazolam degradation significantly, with the highest degradation at pH 7.0. Water matrix, such as anions (Cl−, HCO3−, NO3−) and humic acid, decreased the degradation of alprazolam by UV/H2O2 treatment. Based on the degradation products identified using quadrupole time-of-flight mass spectrometer, the degradation mechanisms of alprazolam by UV/H2O2 treatment were proposed, and hydroxylation induced by ·OH was the main reaction pathway. The degradation of 17 benzodiazepines by UV/H2O2 treatment in wastewater treatment plant effluent and river water was lower than that in phosphate buffer solutions. The results showed that the benzodiazepine psychoactive drugs in natural water can be effectively removed by the UV/H2O2 treatment.
研究领域:
环境科学
·
药理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Jiahui Zhang,Wenliang Zhang,Yue Wang,Shaoyi Jiang,Yan Wang,Zhezheng Ding,Xiaomin Liu
2,4-dichlorophenoxyacetic (2,4-D) acid and 4-chlorophenoxyacetic acid (4-CPA), as widely utilized organochlorine pesticides , are normally detected in wastewater and atmosphere. Their harmfulness to the ecosystem cannot be ignored. UV/H 2 O 2 is one of the most conventional advanced oxidation processes, which has remarkable advantages for the removal of refractory organic pollutants in wastewater. However, the reaction mechanisms and pathways of pollutants with reactive radicals are still unclear. In this study, the degradation efficacy and mechanisms during the photodegradation of 2,4-D and 4-CPA in UV/H 2 O 2 processes were investigated by experiments and density functional theory calculations. The results showed that 2,4-D was more likely to be degraded by UV/H 2 O 2 treatment than UV photolysis alone. In contrast, 4-CPA can be degraded effectively and rapidly under UV irradiation alone. By LC-MS analysis, the degradation products of 2,4-D and 4-CPA in the UV/H 2 O 2 processes were identified and they were produced by hydroxylation and photolysis. Therefore, we speculated a competition mechanism presented between direct photolysis and indirect photolysis in the UV/H 2 O 2 degradation of 2,4-D and 4-CPA. The OH-initiated reaction mechanisms of 2,4-D and 4-CPA in aqueous environments were investigated using quantum chemical methods SMD/M06–2X/6–311++G (3df, 2p)//SMD/M06–2X/6-311 + G (d,p). The pH dependence of the reaction mechanisms and rate constants in their degradation process induced by ·OH was also investigated. The calculation results showed that the ionic forms (2,4-D - and 4-CPA - ) were more prone to react with ·OH in comparison to the corresponding molecular forms (2,4-D and 4-CPA). The total rate constants of 2,4-D and 4-CPA with OH increased with the pH from 1 to 10, and decreased with continued pH increase. The toxicities of 2,4-D, 4-CPA and their products were assessed by the QSAR-based toxicity evaluation software. The results showed that several products were more toxic than their parent compounds, such as 2,4-dichlorophenol, 3,5-dichlorocatechol, 4-chlorophenol and hydroquinone . This work can contribute to clarifying the environmental risks of 2,4-D and 4-CPA and offer a complete understanding for the photodegradation behavior of 2,4-D and 4-CPA in aqueous ecosystems.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Science of Advanced Materials
·
2019
·Vol. 11
·期 6
·842-853
·
IF 1.158
Xu Qiyao,Liu Hongxia,Zheng Huaili,Liang Jianjun
In this study, a new cationic polyacrylamide (CPAM) was successfully synthesized through UV-H2O2-initiated polymerization technique using acryloyloxyethyl trimethyl ammonium chloride (DAC) and acrylamide (AM) as monomers, and applied to sludge dewatering experiments.
Parameters affecting the molecular weight and conversion of the polymers, including total monomer concentration, monomer concentration of DAC, H2O2 concentration, pH and illumination time were examined. Fourier transform infrared spectroscopy (FT-IR), 1H nuclear
magnetic resonance spectroscopy (1H NMR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were employed to characterize the properties of the polymers. The results showed that CPAM was successfully synthesized and possessed a coarse and porous surface morphology
and inferior thermal stabilities. When the dosage of polymer was 40 mg L–1 and the initial sludge pH value was 7.0, PAD-3 (cationic degree: 40%, molecular weight: 6.89 × 106 Da) showed a more excellent sludge dewatering performance (FCMC: 70.6% SRF: 2.8 ×
1012 m · kg –1; d
50: 436.802 μm, Df
: 1.59). During the sludge flocculation process, three mechanisms containing charge neutralization, patching and bridging co-contributed to a prominent flocculation performance.
研究领域:
环境科学
·
高分子化学
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2023
·
IF 11.2
Biyang Zhu,Dongxiao Sun-Waterhouse,Lijun You
UV/H 2 O 2 process is increasingly used to degrade carbohydrates, though the underlying mechanisms remain unclear. This study aimed to fill this knowledge gap, focusing on mechanisms and energy consumption involved in hydroxyl radical (•OH)-mediated degradation of xylooligosaccharides (XOSs) in UV/H 2 O 2 system. Results showed that UV photolysis of H 2 O 2 generated large amounts of •OH radicals, and degradation kinetics of XOSs fitted with a pseudo-first-order model. Xylobiose (X 2 ) and xylotriose (X 3 ), main oligomers in XOSs, were attacked easier by •OH radicals. Their hydroxyl groups were largely converted to carbonyl groups and then carboxy groups . The cleavage rate of glucosidic bonds was slightly higher than that of pyranose ring, and exo -site glucosidic bonds were more easily cleaved than endo -site bonds. The terminal hydroxyl groups of xylitol were more efficiently oxidized than other hydroxyl groups of it, causing an initial accumulation of xylose . Oxidation products from xylitol and xylose included ketoses , aldoses , hydroxy acids and aldonic acids , indicating the complexity of •OH radical-induced XOSs degradation. Quantum chemistry calculations revealed 18 energetically viable reaction mechanisms, with the conversion of hydroxy-alkoxyl radicals to hydroxy acids being the most energetically favorable (energy barriers <0.90 kcal/mol). This study will provide more understanding of •OH radicals-mediated degradation of carbohydrates.
研究领域:
生物化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Chen-Yan Hu,Yuan-Zhang Hou,Yi-Li Lin,Yan-Guo Deng,Shuang-Jing Hua,Yi-Fan Du,Chiu-Wen Chen,Chung-Hsin Wu
The degradation rates and kinetics of one commonly used iodinated contrast medium, iohexol, were investigated and compared during ultraviolet (UV) photolysis, UV/H 2 O 2 and UV/ S 2 O 8 2 − advanced oxidation processes (AOPs). Results indicate that the iohexol degradation rate increased in the order of UV/H 2 O 2 < UV irradiation < UV/ S 2 O 8 2 − and followed pseudo-first-order kinetics. Increasing persulfate concentration significantly increased iohexol degradation rate, whereas increasing H 2 O 2 concentration caused reverse effect. Radical scavenging test results show that UV photolysis, OH and radicals all contributed to iohexol degradation during UV/ S 2 O 8 2 − , but OH was the main contributor during UV/H 2 O 2 and was consumed by excess H 2 O 2 . The kinetic models of iohexol degradation by both AOPs were developed, and the reaction rate constants with OH and were calculated as 5.73 (±0.02) × 10 8 and 3.91 (±0.01) × 10 10 M −1 s −1 , respectively. Iohexol degradation rate remained stable at pH 5–9 during UV irradiation and UV/H 2 O 2 , but gradually decreased at pH 5–7 and remained stable at pH 7–9 during UV/ S 2 O 8 2 − . The presence of anions displayed inhibitory effects on iohexol degradation during UV/ S 2 O 8 2 − in the order of Cl − > HCO 3 − ≫ S O 4 2 − . UV/ S 2 O 8 2 − AOP exhibited high degradation efficiency and stability on the basis of UV irradiation, which can be applied as a promising degradation method for iohexol. UV/ S 2 O 8 2 − AOP can effectively mineralize iohexol to CO 2 but promoted the generation of toxic iodoform (CHI 3 ), and the subsequent chlorination had the potential to reduce the content of disinfection by-products; therefore, further evaluation of possible environmental hazards is warranted.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Biyang Zhu,Yifan Chen,Shiyuan Chang,Huamai Qiu,Lijun You
Kinetic models and mechanism of isomaltooligosaccharides (IMOs) by hydroxyl ( OH) radicals-driven degradation in ultraviolet/hydrogen peroxide system were investigated. Electron paramagnetic resonance spectra indicated that UV radiation played an important role in the steady generation of OH radicals. The OH radicals could effectively decrease the molecular weight of IMOs and significantly oxidize hydroxy group into carbonyl and carboxy groups . Main components of IMOs were separated and identified by HPAEC-PAD and UHPLC-MS/MS methods. Degradation behaviors of IMOs were well fitted to pseudo first-order kinetics. The hydrogen abstraction by OH radicals from different C H sites at pyranose ring began a cascade reaction leading to cleavage of α-glycosidic linkage or C C bonds with formation of stable uronic/aldonic acids. Degradation rate was closely influenced by the degree of polymerization (DP) of IMOs, the initial concentrations of IMOs and H 2 O 2 . The results would pave the way for free radicals-driven degradation of polysaccharides .
研究领域:
食品科学
·
环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PLoS One
·
2021
·Vol. 16
·期 10
·e0258483
·
IF 3.24
Wenping Dong,Chuanxi Yang,Lingli Zhang,Qiang Su,Xiaofeng Zou,Wenfeng Xu,Xingang Gao,Kang Xie,Weiliang Wang
This study investigates the degradation of nifedipine (NIF) by using a novel and highly efficient ultraviolet light combined with hydrogen peroxide (UV/H 2 O 2 ). The degradation rate and degradation kinetics of NIF first increased and then remained constant as the H 2 O 2 dose increased, and the quasi-percolation threshold was an H 2 O 2 dose of 0.378 mmol/L. An increase in the initial pH and divalent anions (SO 4 2- and CO 3 2- ) resulted in a linear decrease of NIF (the R 2 of the initial pH, SO 4 2- and CO 3 2- was 0.6884, 0.9939 and 0.8589, respectively). The effect of monovalent anions was complex; Cl - and NO 3 - had opposite effects: low Cl - or high NO 3 - promoted degradation, and high Cl - or low NO 3 - inhibited the degradation of NIF. The degradation rate and kinetics constant of NIF via UV/H 2 O 2 were 99.94% and 1.45569 min -1 , respectively, and the NIF concentration = 5 mg/L, pH = 7, the H 2 O 2 dose = 0.52 mmol/L, T = 20 ℃ and the reaction time = 5 min. The ·OH was the primary key reactive oxygen species (ROS) and ·O 2 - was the secondary key ROS. There were 11 intermediate products (P345, P329, P329-2, P315, P301, P274, P271, P241, P200, P181 and P158) and 2 degradation pathways (dehydrogenation of NIF → P345 → P274 and dehydration of NIF → P329 → P315).
研究领域:
环境科学
·
药学
✓ 已验证
DOI
PubMed
高影响因子
WATER RESEARCH
·
2015
·
IF 5.528
Shixiang Feng,Xu Zhang,Yanxiang Liu
The phototransformation of acetaminophen (APAP) by UV/H 2 O 2 in deionized water and sewage treatment plant (STP) effluents was studied systematically by a combination of analysis of the reaction intermediates and kinetic study. 1-(2-amino-5-hydroxyphenyl)ethanone ( P1 ) and the reported N -(3,4-dihydroxyphenyl)acetamide ( P2 ) were identified as the main transformation intermediates during the transformation of APAP by UV/H 2 O 2 . There was no influence of OH on the formation kinetics of P1 , while its decay was promoted. The formation and decay kinetics of P2 were accelerated by increases in the concentration of OH. The second-order rate constants for the reaction of OH with APAP, P1 , and P2 were 3.9 × 10 9 , 8.1 × 10 9 , and 4.7 × 10 9 M −1 s −1 , respectively. The kinetic study indicated that the main transformation of APAP also included transformation to 1,4-hydroquinone, although the accumulated concentration of 1,4-hydroquinone was quite low. The presence of anions (Cl − , HCO 3 − / CO 3 2 − , NO 2 − / NO 3 − ), humic acid , commercial drug components or adjuvants, and dissolved organic matters in STP effluents not only changed the transformation kinetics of APAP, but also altered the distribution of the intermediates. The kinetics and pathway of APAP transformation in STP effluent were markedly different from those in deionized water.
研究领域:
环境科学
·
药理学
·
化学动力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Pin Wang,Lingjun Bu,Yangtao Wu,Wangchi Ma,Shumin Zhu,Shiqing Zhou
The study investigated the degradation kinetic and transformation mechanism of ibuprofen (IBP) in UV/H 2 O 2 process from both experimental and theoretical aspects. Impacts of H 2 O 2 dosage, solution pH, quenching agent, and concentration of nitrite (NO 2 − ) on IBP degradation in UV/H 2 O 2 process were evaluated. Both experimental results and theoretical calculations indicated that • OH played an important role in the degradation of IBP and its transformation products . The second-order rate constants of • OH and • NO 2 with IBP were calculated as 3.93 × 10 9 M −1 s −1 and 5.59 × 10 −3 M −1 s −1 , based on the transition state theory, which explained the phenomenon that addition of NO 2 − inhibited IBP degradation. Further, according to the results of ultra-high-resolution mass and density functional theory calculations, mechanisms of a detailed degradation pathway for IBP were clarified. Namely, the detailed mechanistic formation pathways for hydroxylated and keto-based products were proposed. Then, possible active sites of the keto-based products, as well as the corresponding subsequent products were predicted by Condensed Fukui Function. Our study can broaden the knowledge of the reactions of emerging contaminants with • OH, and provide theoretical foundation for the optimization of UV/H 2 O 2 process.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Yueli Chen,Huilin Huang,Runying Luo,Aiping Zhang
Landfill leachate contains high levels of refractory organic compounds that pose significant environmental risks. The treatment of landfill leachate through advanced oxidation processes (AOPs) is an effective method for removing these compounds. However, the presence of chloride ions (Cl − ) might lead to the formation of chlorinated organics. In this study, we compared the formation of chlorinated organics during the removal of refractory organic compounds from landfill leachate treated by a membrane bioreactor (MBR) through UV/H 2 O 2 and UV/PDS processes with different oxidant dosages. The relationship between the formation of chlorinated organics and the concentration of organics was explained via ultraviolet visible spectra, three-dimensional excitation and emission matrix spectra, and total organic carbon. The results revealed that the concentration of chlorinated organics increased with increasing oxidant dosage. Under the oxidant dosage of 40 mM and a reaction time of 90 min, the cumulative concentration of the 4 chlorinated organics in the UV/H 2 O 2 process reached 482.8 μg/L, and those of the 8 chlorinated organics reached 34,370.2 μg/L in the UV/PDS process. Concentrations of chloroacetaldehyde, chloroacetic acid and trichloroacetic acid produced in the UV/H 2 O 2 process and concentrations of chloroacetaldehyde, dichloroacetaldehyde and dichloroacetonitrile produced in the UV/PDS process were significantly and positively correlated with the concentrations of aromatic organic compounds. In the UV/H 2 O 2 and UV/PDS processes, the concentration of Cl − affects the conversion of reactive chlorine species, such as Cl • and Cl 2 •– , and the reactive species, such as HO • , SO 4 •– , Cl • and Cl 2 •– generated in the process react with organic compounds to form intermediates through hydrogen extraction, addition and electron transfer processes that gradually open ring structures to form small molecules. Cl • and Cl 2 •– further react with these small-molecule intermediates to form chlorinated organics through chlorine substitution. The toxicity evaluation of chlorinated organics revealed that haloacetaldehydes were the main source of chlorinated organic toxicity in both the UV/H 2 O 2 and UV/PDS processes. This study provides theoretical support for reducing the formation of chlorinated organics during refractory organic compound removal processes from landfill leachate via advanced oxidation processes such as UV/AOPs.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Kai Yin,Lin Deng,Jinming Luo,John Crittenden,Chengbin Liu,Yuanfeng Wei,Longlu Wang
Phenicol antibiotics (PABs) degradation by UV/H 2 O 2 is important because we need to determine the reduction in toxicity and disinfection byproducts for post-chlorine. In this study, the degradation of PABs, including florfenicol (FLO), chloramphenicol (CAP) and thiamphenicol (THA), was examined. The pseudo-first order degradation rate constants of PABs were 3 times higher in ultrapure water (UW) than that in synthetic wastewater (SW) for these conditions: [PABs] 0 = 1 μM, [H 2 O 2 ] = 0.1 mM, and I 0 = 1.985 × 10 −6 E L −1 s −1 . Fulvic acid (FA) and HCO 3 – inhibited PABs degradation, Cl − and NO 3 – concentrations of up to 5 mM and 10 mM had a negligible impact. The impact of water matrix on PABs degradation was successfully predicted using pseudo-steady-state kinetic model. The degradation of PABs was triggered via hydroxylation and/or hydrogen abstraction. The treatment of PABs via UV/H 2 O 2 could decrease their antimicrobial properties, while the byproducts of FLO and THA showed higher acute toxicity in Vibrio fischeri . In addition, two identification products (TP-276 and TP-354) of FLO had higher ecotoxicity toxicity (using ECOSAR) in fish, daphnid and green algae. The trichloromethane formation potential (TCMFP) for PABs with post-chlorination in UW and SW can be reduced after UV/H 2 O 2 compared to UV, and is related to the corresponding decrease of dissolved organic carbon (DOC).
研究领域:
环境科学
·
毒理学
·
水处理工程
✓ 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）