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
Water
·
2019
·Vol. 11
·期 12
·2639
·
IF 2.524
Chi Wang,Zhian Ying,Ming Ma,Mingxin Huo,Wu Yang
The utilization of reclaimed water is a reliable and sustainable approach to enhance water supply in water-deficient cities. However, the presence of micro-organic pollutants (MPs) in reclaimed water has potential adverse effects on aquatic ecosystems and human health. In this study, we investigated the occurrence of 12 target MPs in the influent and reclaimed water collected from a local wastewater treatment plant, and the ultraviolet (UV)–chlorine process was applied to analyze its ability to remove MPs. The results showed that all 12 MPs were detected in both the influent and the reclaimed water, with the concentrations ranging from 25.5 to 238 ng/L and 8.6 to 42.5 ng/L, respectively. Over 52% of all the target MPs were readily degraded by the UV–chlorine process, and the removal efficiency was 7.7% to 64.2% higher than the corresponding removal efficiency by chlorination or UV irradiation only. The degradation efficiency increased with the increasing initial chlorine concentration. The pH value had a slight influence on the MP degradation and exhibited different trends for different MPs. The formation of known disinfectant byproducts (DBPs) during the UV–chlorine process was 33.8% to 68.4% of that in the chlorination process, but the DBPs’ formation potentials were 1.3 to 2.2 times higher. The toxicity assay indicated that UV–chlorine can effectively reduce the toxicity of reclaimed water.Keywords:MPs;UV–chlorine process;disinfectant byproducts;toxicity
研究领域:
环境科学
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水处理
·
毒理学
✓ 已验证
产品关联
DOI
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
INTERNATIONAL JOURNAL OF CHEMICAL KINETICS
·
2023
·
IF 1.5
Jialong Zhu,Kaixuan Fang,Mengdi Zhang,Huixuan Chen,Mengfei Zhou,Xiaofang Sun
In this study, the kinetics and mechanism of UV/O 3 synergistic oxidative digestion of dissolved organic phosphorus (DOP) were investigated, focusing on the ozone direct oxidation and hydroxyl radical oxidation parts of glufosinate and triphenyl phosphate (TPhP). The p-chlorobenzoic acid (p-CBA) was selected as the probe compound, and two kinds of reaction kinetic models were proposed by competitive kinetic method with R ct according to the different scale of rate constants of hydroxyl radical oxidation. Under the condition of weakly alkaline (pH = 9.0) and weakly acidic environment (pH = 5.0), the second-order rate constants of glufosinate and TPhP was determined indirectly to be k o 3/glufosinate = (2.903 ± 0.247)M −1 s −1 and k o 3/TPhP = (3.307 ± 0.204) M −1 s −1 by ozone direct oxidation, and k ·OH/glufosinate = (1.257 ± 1.031) × 10 9 M −1 s −1 and k ·OH/TPhP = (7.120 × 10 8 ± 0.963) M −1 s −1 by hydroxyl radical oxidation, respectively. The comparison of the contribution levels of the two parts to the digestion process showed that the contribution levels in the digestion of glufosinate and TPhP processes both the contribution of ·OH were higher than those of ozone, 86.3% and 72.6%, respectively.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2023
·
IF 2.8
Chen-Yan Hu,Cun Xiong,Yi-Li Lin,Tian-Yang Zhang
The degradation kinetics, reaction pathways, and disinfection by-products formation of an organic UV filter, benzophenone-4 (BP4) during UV/persulfate oxidation were investigated. BP4 can hardly be degraded by UV alone, but can be effectively decomposed by UV/persulfate following pseudo-first order kinetics. BP4 degradation rate was enhanced with increasing persulfate dosage and decreasing pH from 8 to 5. However, the degradation rate of BP4 at pH 9 was higher than that at pH 8 because of the presence of phenolic group in BP4 structure. and SO4−⋅ were confirmed as the major contributors to BP4 decomposition in radical scavenging experiments, and the second-order rate constants between HO⋅ and BP4 as well as those between SO4−⋅ and BP4 were estimated by establishing and solving a kinetic model. The presence of Br− and humic acid inhibited the decomposition of BP4, while NO3− promoted it. The mineralisation of BP4 was only 9.1% at the persulfate concentration of 50 μM. Six degradation intermediates were identified for the promulgation of the reaction pathways of BP4 during UV/persulfate oxidation were proposed as a result. In addition, the formation of DBP in the sequential chlorination was evaluated at different persulfate dosages, pH values, and water matrix. The results of this study can provide essential knowledge for the effective control of DBP formation with reducing potential hazard to provide safe drinking water to the public.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BMC Complementary Medicine and Therapies
·
2020
·Vol. 20
·期 1
·1-10
·
IF 0
Li Hong-Ying,Fang Jiang-Ji,Shen Hua-Dan,Zhang Xue-Qiong,Ding Xiao-Ping,Liu Jun-Feng
Background Quantitation analysis and chromatographic fingerprint of multi-components are frequently used to evaluate quality of herbal medicines but fail to reveal activity of the components. It is necessary to develop a rational approach of chromatography coupled with activity detection for quality assessment of herbal medicines. Methods An on-line HPLC-ultraviolet detection-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging (HPLC-UV-ABTS) method was developed to obtain the chromatographic fingerprints and ABTS +• inhibition profiles (active fingerprints) of Rehmanniae Radix (Dihuang) and Rehmannia Radix Praeparata (Shu Dihuang). Eighteen compounds showing ABTS +• inhibition activity were identified by HPLC-fourier-transform mass spectrometry (HPLC-FTMS). Verbascoside was used as a positive control to evaluate the total activities of the samples and the contribution rate of each compound. The similarities of the chromatographic and active fingerprints were estimated by the vectorial angle cosine method. Results The results showed that the HPLC-UV-ABTS method could efficiently detect antioxidant activity of the herbal medicine samples. The antioxidants were different between the two herbs and several new antioxidants were identified in Shu Dihuang. A function equation was generated in terms of the negative peak area (x) and the concentrations of verbascoside (y, μg/mL), y = 2E-07 × 4 - 8E-05 × 3 + 0.0079 × 2 + 0.5755x + 1.4754, R 2 = 1. Iridoid glycosides were identified as main antioxidants and showed their higher contributions to the total activity of the samples. The total contributions of the three main active components in the Dihuang and Shu Dihuang samples to the total activity, such as echinacoside, verbascoside and an unknown compound, were 39.2–58.1% and 55.9–69.4%, respectively. The potencies of the main active components in the Shu Dihuang samples were two to ten times those in the Dihuang samples. Similarity values for S12 in the chromatographic fingerprints and S03, S12 and P03 in the active fingerprints were less than 0.9. The three batches of samples might show their different quality with the other samples. Conclusions The results suggested that the combination of “quantity-effect” research strategy and the HPLC-UV-ABTS analysis method could comprehensively evaluate the active components and quality of Dihuang and Shu Dhuang.
研究领域:
中药学
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分析化学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
Journal of Water Process Engineering
·
2021
·
IF 5.485
Jialin Chen,Ruina Zhang,Dong Chen,Jianyong Liu,Shanping Chen
The generation process for the highly reductive carbon dioxide radical ( CO 2 − ) in the Fe(III)-oxalate system is enhanced under UV irradiation and used in nitrate (NO 3 − ) reduction with improved product selectivity to nitrogen (N 2 ). The combination of Fe(III) and residual oxalate forms Fe(III)-oxalate complexes again for an Fe(II)/Fe(III) species cycle and achieves generation of CO 2 − radical continually. The electron paramagnetic resonance (EPR) spectrum demonstrates the existence of CO 2 − radicals in this process. Some of the important control factors, such as initial concentrations of ferric ions (Fe(III)) (0.5, 1, 2, and 3 mM), NO 3 − (14, 21, and 42 mg N/L), oxalate (3, 7, and 10 mM), and pH values (2, 3, 4, 5, and 6), are systematically assessed for NO 3 − reduction efficiency and N-species selectivity. Among all the control factors mentioned, pH is a key parameter with an important role in the NO 3 − reduction process. Excellent NO 3 − reduction efficiency (∼90 %) was achieved at pH 3 in the presence of 1 mM Fe(III) and 10 mM oxalate under UV irradiation for 120 min. High Fe(III) and oxalate concentrations promote NO 3 − removal. In addition, there was an increase in the NO 3 − removal amount with a greater initial NO 3 − concentration. About 60 % of NO 3 − can be selectively reduced to N 2 with low selectivity to NO 2 − (∼3.4 % of total N) and NH 4 + (∼15.7 % of total N). In general, the UV/Fe(III)-oxalate system provided an alternative way to improve NO 3 − removal performance and selectivity to form N 2 in water and wastewater remediation processes.
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
CHEMOSPHERE
·
2021
·
IF 7.086
Anhong Cai,Jing Deng,Cheng Ye,Tianxin Zhu,Xiao Ling,Shuwen Shen,Hongguang Guo,Xueyan Li
N,N-Diethyl-3-methyl benzoyl amide (DEET) has been detected as an emerging pollutant in various water bodies because of its widespread use as an insect repellent. In this study, the combination of UV-LED 275 and iron-containing coagulant (FeCl 3 ) was used for the elimination of DEET in water. It was found that UV-LED 275 /FeCl 3 (98 %) system presented a favorable removal of DEET compared with UV 254 /FeCl 3 (59 %) and UV-LED 275 /Fe 2 (SO 4 ) 3 (81 %) processes at initial pH 3.5. DEET degradation by both UV-LED 275 /FeCl 3 and UV-LED 275 /Fe 2 (SO 4 ) 3 processes followed pseudo-first-order kinetics with the calculated pseudo-first-order rate constants ( k obs ) of 0.0105 and 0.0046 cm 2 mJ −1 , respectively. The results of ESR analysis and radicals quenching experiments indicated that hydroxyl radicals ( OH) and superoxide radicals (O 2 − ) were responsible for DEET degradation in UV-LED 275 /FeCl 3 process, and the former played the major role. An increase in FeCl 3 dosage was beneficial to the degradation. In the UV-LED 275 /FeCl 3 process, DEET degradation increased with a decrease in pH from 3.5 to 3.0, whereas it was almost completely suppressed with an increase in pH from 4.3 to 6.3. DEET degradation was almost unchanged after the introduction of NO 3 − , and it impeded after the addition of humic acid (HA), HCO 3 − , and SO 4 2− . The plausible degradation pathway mainly involved hydroxylation, cleavage of the C–N bond, acetylation , and dealkylation. Among the disinfection by-products (DBPs) evaluated, UV-LED 275 /FeCl 3 pretreatment generally increased the generation of trichloromethane, chloral hydrate, dichloroacetic acid, and trichloroacetic acid, which implied that further assessment of environmental risk was needed during its practical applications.
研究领域:
环境科学
·
水处理
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 7
·5877-5897
·
IF 2.993
Zhang Jiancheng,Li Liping,Guo Ruilu,Zhou Haorui,Li Zhiming,Chen Guangxin,Zhou Zheng,Li Qifang
Methacryloxypropyl-polyhedral oligomeric silsesquioxane (MAP-POSS) was photopolymerized with the tri- or tetra-functional thiol monomer in different stoichiometry. A novel inorganic–organic methacrylate hybrid material with highly cross-linked network and high performance was synthesized by UV-initiated thiol–ene click chemistry. SEM–EDAX images and XRD diffractograms showed that no agglomeration of MAP-POSS was observed, indicating MAP-POSS dispersed uniformly in the hybrid materials. Real-time FTIR was employed to monitor the conversion of thiol and methacrylate as a function of irradiation time, and the results revealed that highly thiolated monomer could promote the conversion of methacrylate effectively because of stronger chain propagation capability. The TGA indicated that the hybrid materials had high thermal stability of which the onset decomposition temperature rose to 350 °C, approximately 50 °C higher than that of the traditional UV-cured epoxy acrylate/triethylene glycol dimethacrylate (EA/TEGDMA, 70:30 w/w) resin. The highest glass transition temperature ( T g ) of the hybrid materials was 76.2 °C. Compared with traditional EA/TEGDMA resins, the novel hybrid materials consisted of MAP-POSS had fast curing rate, high mechanical properties and thermal stability which made the wider practical applications of UV-cured hybrid materials feasible.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2019
·Vol. 12
·期 2
·141-148
·
IF 2.378
Xue Ren,Man He,Beibei Chen,Bin Hu
Herein, magnetic porous organic polymers (MOPs) prepared via an azo coupling reaction in water under mild conditions are evaluated for the extraction of seven cardiovascular drugs, including xylocaine, metoprolol, mexiletine, labetalol, propranolol, carvedilol and propafenone, from human urine samples for the first time. The extraction mechanisms are assumed to be electrostatic interaction and π–π stacking. The MOPs exhibited fast adsorption/desorption time (13 min) and high enrichment factors (315–365-fold) for target analytes. Based on this, a method coupling magnetic solid phase extraction with HPLC-UV detection was developed for the analysis of cardiovascular drugs. Under the optimized conditions, the LODs (S/N = 3) were in the range of 0.06–0.57 μg L−1 with an RSD (n = 5) of 4.3–8.6%, and the linear range was 0.2–200 μg L−1 for propranolol, 2–200 μg L−1 for metoprolol, and 0.5–200 μg L−1 for the other five analytes. The developed method was applied for the analysis of cardiovascular drugs in urine samples with recoveries of 89.0–112%. In order to further evaluate the application potential of this method, real-time monitoring of metoprolol in urine samples collected from volunteers treated with metoprolol tablets was performed. The proposed method is simple, fast, and sensitive and has good potential in the monitoring of cardiovascular drugs in competitive sports and clinical analysis.
研究领域:
分析化学
·
药理学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Huaying Liu,Biaojun Zhang,Yingjie Li,Qi Fang,Zhichao Hou,Senlin Tian,Junjie Gu
Degradation of sulfapyridine as a representative sulfonamide by the UV/chlorine process was investigated. Kinetic experiments revealed that aniline and sulfonamide moieties were sulfapyridine’s main reaction sites with •OH, and the aniline moiety was the preferable site for Cl• attack. Effects of four influence factors (pH; humic acid, HA; HCO3–; Cl–) on the degradation kinetics were explored by response surface methodology, and it was found that pH and HA have the highest level influence (81%) among all influence variables (linear, quadratic, and interactive terms), and low pH and concentrations of HA were beneficial for degradation. Approximately 70% of sulfapyridine degradation was observed within 60 min in the UV/chlorine system (pH = 5) without HA. A kinetic model considering steady-state concentrations of reactive radicals and their second-order rate constants is suitable for predicting sulfapyridine degradation, elucidating that •OH and Cl• are major radicals for sulfapyridine degradation in freshwater, and •OH and Cl2•– are responsible for the degradation in coastal seawater.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Yingxue Wu,Xianhong Zhang,Dong Chen,Yuhong Ma,Qin Wang,Jiadong Wang,Wantai Yang
Branched polyacrylamides (PAMs) have shown tremendous potential in wastewater treatment, papermaking, and oil drilling due to their unique molecular structure, remarkable shear stability, and effective flocculability. Efficient approaches for their industrial-scale production have attracted increasing attention. Herein, we report a facile, scalable, highly efficient, and cost-effective strategy for the production of branched PAMs through UV polymerization of acrylamide (AM) initiated with a novel water-soluble macro-photoinitiator. Through precipitation copolymerization of AM and 2-hydroxy-1-[4-(2-acryloyloxyethoxy)phenyl]-2-methyl-1-propanone (M2959), poly(AM-co-M2959)s bearing photoinitiator moieties on the backbone were successfully synthesized, which showed excellent water solubility and high photoinitiation efficiency. Most importantly, both the branching degree and main-chain length of the branched PAMs were controllable, given that the molar mass and photoinitiating group content of poly(AM-co-M2959)s could be effectively controlled by adjusting the monomer feed ratio of AM/M2959. The rheological properties of the resultant branched PAMs were characterized in detail, and excellent water solubility and shear resistance were observed, confirming the well-defined branched structure of the as-prepared PAMs. Due to their facile synthesis, simplicity of operation, and high photoinitiation efficiency, these novel macro-photoinitiators have great potential as a versatile platform for the preparation of various branched polymers containing different functional groups (not limited to branched PAMs).
研究领域:
高分子化学
·
材料科学
·
环境工程
✓ 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）