Journal of Environmental Sciences
·
2016
·
IF 2.208
Suqi Li,Jing Xu,Wei Chen,Yingtan Yu,Zizheng Liu,Jinjun Li,Feng Wu
p -Arsanilic acid ( p -ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth. The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV–Vis light excitation. This work examined the initial rate and efficiency of p -ASA phototransformation under UV-C disinfection lamp. Several factors influencing p -ASA phototransformation, namely, pH, initial concentration, temperature, as well as the presence of NaCl, NH 4 + , and humic acid , were investigated. Quenching experiments and LC–MS were performed to investigate the mechanism of p -ASA phototransformation. Results show that p -ASA was decomposed to inorganic arsenic (including As(III) and As(V)) and aromatic products by UV-C light through direct photolysis and indirect oxidation. The oxidation efficency of p -ASA by direct photosis was about 32%, and those by HO and 1 O 2 were 19% and 49%, respectively. Cleavage of the arsenic–benzene bond through direct photolysis, HO oxidation or 1 O 2 oxidation results in simultaneous formation of inorganic As(III), As(IV), and As(V). Inorganic As(III) is oxidized to As(IV) and then to As(V) by 1 O 2 or HO . As(IV) can undergo dismutation or simply react with oxygen to produce As(V) as well. Reactions of the organic moieties of p -ASA produce aniline, aminophenol and azobenzene derivatives as main products. The photoconvertible property of p -ASA implies that UV disinfection of wastewaters from poultry and swine farms containing p -ASA poses a potential threat to the ecosystem, especially agricultural environments.
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Wen-Long Wang,Zi-Bo Jing,Yi-Lin Zhang,Qian-Yuan Wu,Jörg E. Drewes,Min-Yong Lee,Uwe Hübner
Low-pressure mercury lamps with high-purity quartz can emit both vacuum-UV (VUV, 185 nm) and UV (254 nm) and are commercially available and promising for eliminating recalcitrant organic pollutants. The feasibility of VUV/UV as a chemical-free oxidation process was verified and quantitatively assessed by the concept of H2O2 equivalence (EQH2O2), at which UV/H2O2 showed the same performance as VUV/UV for the degradation of trace organic contaminants (TOrCs). Although VUV showed superior H2O activation and oxidation performance, its performance highly varied as a function of light path length (Lp) in water, while that of UV/H2O2 proportionally decreased with decreasing H2O2 dose regardless of Lp. On increasing Lp from 1.0 to 3.0 cm, the EQH2O2 of VUV/UV decreased from 0.81 to 0.22 mM H2O2. Chloride and nitrate hardly influenced UV/H2O2, but they dramatically inhibited VUV/UV. The competitive absorbance of VUV by chloride and nitrate was verified as the main reason. The inhibitory effect was partially compensated by •OH formation from the propagation reactions of chloride or nitrate VUV photolysis, which was verified by kinetic modeling in Kintecus. In water with an Lp of 2.0 cm, the EQH2O2 of VUV/UV decreased from 0.43 to 0.17 mM (60.8% decrease) on increasing the chloride concentration from 0 to 15 mM and to 0.20 mM (53.5% decrease) at 4 mM nitrate. The results of this study provide a comprehensive understanding of VUV/UV oxidation in comparison to UV/H2O2, which underscores the suitability and efficiency of chemical-free oxidation with VUV/UV.
研究领域:
环境工程
·
水处理
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2015
·
IF 2.358
Jinyue Dai,Songqi Ma,Yonggang Wu,Jin Zhu,Xiaoqing Liu
A series of bio-based unsaturated polyesters was synthesized by melt polycondensation of itaconic acid with 1,4-butanediol and glycerol. Their chemical structures were confirmed by FT-IR, 1 H NMR, acid and hydroxyl values. Waterborne UV curable dispersion coatings based on these polyesters and acrylated epoxidized soybean oil (AESO) were formulated. The average particle size and their stability before curing as well as the coating properties after curing, including adhesion, flexibility, pencil hardness and solvent resistance, were investigated. Results demonstrated that the glycerol segment in the polyesters together with AESO led to the excellent coating properties in terms of highest grade of adhesion (5B), 0T flexibility, pencil hardness of 5H and excellent solvent resistance (no appearance change after 250 double rubs with ethanol and acetone). This work provided us the coating systems combining the merits of being bio-based, UV-curable and water dispersible.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Tianxin Zhu,Jing Deng,Mengyuan Xu,Anhong Cai,Cheng Ye,Jun Li,Xueyan Li,Qiongsong Li
The degradation of N,N -diethyl- meta -toluamide (DEET) in aqueous solution by the UV/monochloramine (UV/NH 2 Cl) process was examined systematically in this study. DEET was resistant to UV photolysis and chloramination, while the synchronous combination of UV irradiation and NH 2 Cl can effectively eliminate DEET, which was caused by the generation of hydroxyl radicals and reactive chlorine species. The former played the critical role in DEET degradation, while the contribution of the latter can be ignored. Under all investigated experimental conditions, DEET degradation in the UV/NH 2 Cl process followed the pseudo-first-order kinetic model. The water quality parameters exerted the complicated impact. Reducing solution pH and raising water temperature both favored the DEET removal. The presence of sulfate, humic acid and fulvic acid accelerated the degradation, while the introduction of bicarbonate and high-concentration chloride retarded the removal. The plausible degradation pathways of DEET in the UV/NH 2 Cl process were proposed through the combination of QTOF/MS analysis and DFT calculation, and mainly involved in the cleavage of C–N bond, dealkylation, mono- and polyhydroxylation. The acute toxicity of reacted solution underwent a trend of first increasing and then decreasing with the prolonged irradiation time, which can be well illustrated by quantitative structure-activity relationship analysis. Electrical energy per order was employed to determine the energy consumption and the optimal conditions were determined as UV fluence of 369.9–493.2 mJ cm −2 and NH 2 Cl dosage of 5–20 mg L −1 .
研究领域:
环境科学
·
化学工程
·
毒理学
✓ 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
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2022
·
IF 3.571
Xueni Zhong,Qianqian Lv,Qiyun Yong,Wenping Hu,Dan Li,Shuhui Ji,Liuyue Zhan,Wenbin Chen,Min Li,Jinsheng Lin,Cuirong Sun
Elagolix sodium (ELS) is a marketed product using to release moderate to severe endometriosis-associated pain. It contains functional groups such as carboxyl group , secondary amino group , 2,4-dioxo pyrimidinyl and several benzyl or benzyl-like position hydrogen atom that are susceptive to occur stress degradation. Forced degradation studies of ELS reveal different degradation profiles of the drug substance which are conducted under photo, thermal, acidic, neutral, alkaline and hydrogen peroxide oxidative conditions in the direction of the ICH guidances. With structural elucidation of LC-PDA/UV-MS n and NMR, the degradants were identified, and seven new degradants are reported in this study. It is confirmed that most of the degradation behaviors of ELS are related to the carboxyl group and secondary amino group in the 3-carboxyl propylamine side chain. Under the oxidative condition using hydrogen peroxide as the oxidant , the secondary amine was oxidized to form an N -hydrogen amine degradant and two further degradants of amine and carbonyl analogs were generated. Under the alkaline degradation condition, the ELS is proven to be stable and no obvious degradants are produced. On the other hand, under the acidic and neutral degradation condition, the 2,4-dioxo pyrimidinyl core of elagolix sodium is stable but the carboxyl group and secondary amine will occur ring cyclization to form the δ -lactam analogs of elagolix sodium. The plausible mechanisms for the degradation of acidic, thermal, photo-degradative and hydrogen peroxide mediated oxidative of elagolix sodium are proposed. It is worth to note that DP-3–4 are the potential degradants which are only found in the solution degradation and are not the real impurities of elagolix sodium.
研究领域:
药物化学
·
分析化学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Ze-Chen Gao,Yi-Li Lin,Bin Xu,Ying Xia,Chen-Yan Hu,Tian-Yang Zhang,Hao Qian,Tong-Cheng Cao,Nai-Yun Gao
The effect of bromide and iodide on the transformation of humic acid (HA) and algal organic matter (AOM), and the formation of disinfection by-products (DBPs) during UV/chlorination were investigated. Experimental results indicated that the halides effectively inhibited mineralization, with multiple changes in organic molecule transformation due to differences in formation and speciation of reactive halogen species and free halogen. As a consequence, bromide and iodide also played important roles in DBP formation. The DBP yields in HA-containing water during UV/chlorination decreased in the order of iodide loaded > freshwater ≫ bromide loaded, whereas DBP formation in AOM-containing water decreased remarkably with halides added (freshwater > bromide loaded ≫ iodide loaded) at high UV fluence . Moreover, Pearson correlation analysis exhibited weaker correlation between DBPs and water parameters in AOM-containing water, while DBPs in HA-containing water exhibited better correlation with water parameters. For both simulated waters, the theoretical toxicity was calculated and peaked in bromide-containing water, whereas the calculated toxicity in iodide-containing water was comparable or slightly higher than that in freshwater. Therefore, UV/chlorine treatment may achieve good quality water with reduced DBP-associated toxicity in freshwater or iodide-containing water (iodide only), but careful consideration is needed when purifying source waters containing bromide (bromide only), especially for AOM/bromide-containing water.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 31
·4524-4531
·
IF 5.582
Xiaoqing Ai,Jiansen Pan,Qingyi Xie,Chunfeng Ma,Guangzhao Zhang
Hyperbranched polymers with high solubility, low viscosity, low crystallinity and dense functional groups are promising to be used in adhesives and coatings. In this study, we have developed a cleavable hyperbranched poly(ester-co-vinyl) with diethylene glycol units and unreacted pendant vinyl groups via radical ring-opening copolymerization of 2-methylene-1,3-dioxepane (MDO), vinyl acetate (VAc) and diethylene glycol divinyl ether. Such a hyperbranched polymer with vinyl groups can form a crosslinked network by UV curing. The cleavable ester bonds are randomly distributed in the main chain, so they can degrade into small fragments with molar masses of 400–600 g mol−1. The degradation rate can be well regulated with MDO content. The protein resistance, antibacterial adhesion and anti-diatom activity of the hyperbranched polymer were examined. The polymer with diethylene glycol units exhibits remarkable antifouling abilities and can effectively inhibit the adhesion of protein, marine bacteria (Pseudomonas sp.) and diatoms (Navicula incerta). The hyperbranched polymer coating can find application in marine antifouling.
研究领域:
材料科学
·
海洋生物学
·
高分子化学
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·Vol. 40
·期 2
·279-286
·
IF 3.1
Dou Renju,Wang Qin,Ren Xiaoyan,Lu Lehui
Here we employ in-situ UV-Vis spectroscopy to monitor the sulfur redox reaction with oxygen-containing molecules as an additive, for example, biphenyl-4,4′-dicarboxylic acid (BDC). Furthermore, Raman spectrum, electron paramagnetic resonance (EPR), and electrospray ionization-mass spectrometry (ESI-MS) measurements reveal that the formation of BDC-S
•‒ 3
complexes can establish the long-term stability of polysulfide radicals, change the kinetics of sulfur redox reaction, and then generate decent capacity retention and rate capability. According to the density functional theory (DFT) analysis, S
•‒ 3
radicals are the underlying product of S
2‒ 6
cleavage, owing to the decreased chemical energy and the increased stability of S
•‒ 3
radicals through Lewis acid-base interaction. The assembled Li-S batteries with BDC additive deliver a high reversible capacity of 420 mA·h·g −1 over 200 cycles with over 98% Coulombic efficiency, under the current density of 0.2 C.
研究领域:
材料科学
·
电化学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 24
·7660
·
IF 3.4
Xiaohui Zhao,Yutong Liu,Yue Cao,Hui Cao,Huihui Wang,Zhou Yang,Dong Wang,Wanli He
We prepared cholesteric liquid crystal (CLC) films with broadband reflective properties by admixing organic dye UV-327 into inorganic zinc oxide nanoparticles (ZnO NPs), utilizing the principle of pitch distribution from a large to a small gradient along the film thickness direction, leading to broadband reflection. ZnO NPs are poorly dispersed and easy to gather, but they do not decompose easily. The addition of UV-327 makes up for the above shortcomings. UV-327 is an organic compound with good compatibility and dispersion with liquid crystal systems. Therefore, we used the method of mixing two UV-absorbing dyes (UV-327 and ZnO NPs) to obtain CLC films. UV-absorbing dyes (UV-327 and ZnO NPs) made the liquid crystal films form a UV intensity gradient in the direction of thickness, prompting the polymerizable monomers to polymerize faster on the stronger side of the light, leading to the relative diffusion of chiral molecules and polymerizable monomers, forming the concentration gradient of chiral molecules in the direction of thickness. The pitch has a gradient distribution as the chiral concentration varies. Then, anchored by the polymer network, the pitch gradient distribution no longer changes. Broadened reflective bandwidth can reach up to 881 nm. Furthermore, the film covers the near-infrared wavelength band well, which can be applied to future smart windows or laser shielding for medical and military applications. It is also believed that this achievement will optimize the preparation technology of broadband reflective CLC films in the future.Keywords:cholesteric liquid crystal;pitch gradient distribution;broadband reflection;UV-327;zinc oxide nanoparticles
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2017
·
IF 2.603
Xiao Zhao,Youfa Xu,Lifang Zhang,Chunmei Wang,Chunna Guo,Chenzhong Fei,Keyu Zhang,Xiaoyang Wang,Yingchun Liu,Mi Wang,Wenli Zheng,Feiqun Xue
Ethanamizuril (EZL) is a novel anti-coccidial triazine synthesized by the Shanghai Veterinary Research Institute of the Chinese Academy of Agricultural Sciences. As a novel coccidiostat, it is essential to study its residue in food animal tissues. In this study, a reliable UPLC method for the determination of ethanamizuril (EZL) and one of its metabolites (M3) in chicken muscle, skin and fat, liver, and kidney samples was developed. Analytes were extracted using acetonitrile and 10% sodium carbonate solution, defatted by n -hexane, and further purified by using an Oasis MCX cartridge. The calibration curves for both test compounds were linear in all tissue matrices we tested: muscle, skin and fat, liver and kidney. The mean relative recoveries of EZL and M3 were from 87.3% to 103.2% between all tissue samples. The inter-day and intra-day relative standard deviations were within 15% and 20%, respectively. This method is accurate, reproducible and is ready to be field-tested.
研究领域:
兽医学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOFT MATERIALS
·
2024
·
IF 1.6
Chengmin Hou,Weimin Yan
UV water-based inks have disadvantages such as slow curing speed and low degree of crosslinking. In this paper, the copolymer P(MMA-r-HEMA) was prepared by traditional free radical polymerization using methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA) as monomers, and the copolymer P(MMA-r-HEMA) was modified by acrylic acid (AA) to synthesis completely water-soluble acrylic prepolymer P(MMA-r-HEMA)-g-AA. Triethylenetetramine reacted with glycidyl methacrylate (GMA) to yield a multifunctional reactive diluent TGMA. Secondly, acrylic prepolymer P(MMA-r-HEMA)-g-AA, multifunctional reactive diluent TGMA and photoinitiator were used to prepare water-based UV curable ink. The influence of the type and quality of photoinitiator, the relative molecular weight and mass fraction of P(MMA-r-HEMA)-g-AA, the number of functional groups and mass fraction of TGMA on the UV ink curing speed and the wear resistance of the ink film were discussed. When the mass fraction of the photoinitiator TPO was 1%, the number-average relative molecular mass of the prepolymer was 1.67 × 104 g/mol and the mass fraction was 60%, the number of functional groups of the reactive diluent was 6 and the mass fraction was 40%, the light curing of UV water-based ink was completed in 0.1 s, and the mass loss after 50 times abrasion was 0.2–0.4%.
研究领域:
材料科学
·
化学工程
✓ 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）