ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 7
·5132-5140
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IF 2.757
Xu Hai-bo,Zhao Dao-yuan,Li Yu-jiao,Liu Pei-ya,Dong Chang-xun
ortho -Nitrochlorobenzene ( o -NCB) in soil poses significant health risks to human because of its persistence and high toxicity. The removal of o -NCB by both zero-valent iron (ZVI) and chemical oxidation (persulfate) was investigated by batch experiments. The o -NCB removal rate increases significantly from 15.1 to 97.3 % with an increase of iron dosage from 0.1 to 1.0 mmol g −1 . The o -NCB removal rate increases with the decrease of the initial solution pH, and a removal efficiency of 90.3 % is obtained at an initial pH value of 6.8 in this combined system. It is found that temperature and soil moisture could also increase the o -NCB removal rate. The o -NCB degradation rate increases from 83.9 to 96.2 % and from 41.5 to 82.4 % with an increase of temperature (15 to 35 °C) and soil moisture (0.25 to 1.50 mL g −1 ), respectively. Compared to the persulfate oxidation system and ZVI system, the persulfate–iron system shows high o -NCB removal capacity. o -NCB removal rates of 41.5 and 62.4 % are obtained in both the persulfate oxidation system and the ZVI system, while the removal rate of o -NCB is 90.3 % in the persulfate–iron system.
研究领域:
环境科学
·
土壤修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2021
·
IF 5.221
Wang Xiang,Deng Rufeng,Shen Wenbo,Huang Jianbo,Li Qun,Zhao Yuanchao,Wan Jinzhong,Zhou Yan,Long Tao,Zhang Shengtian
Although pesticide intermediates are a kind of typical toxic pollutant in contaminated sites, the remediation of these contaminants in groundwater and soils is of limited concern. In the present study we investigated the performance of a novel heterogeneous oxidation system, biochar supported nanoscaled-zero valent iron (nZVI/BC) activated persulfate (PS), in the oxidative degradation of nitrochlorobenzene (NCB), a typical pesticide intermediate. Peanut shell based nZVI/BC was prepared and used as the PS activator. The degradation kinetics of m-, p-, and o-NCB isomers in the aqueous phase were investigated. The effects of BC/nZVI composition (Fe/BC mass ratio), the amount of BC/nZVI and PS, and initial contaminant concentration on NCB removal were also examined. Results suggest that over 90% removals of three NCB isomers could be obtained by the nZVI/BC activated PS system at initial NCB concentration of 10 mg L−1. The combination of nZVI/BC composite and PS showed superior performance to PS alone. The optimal treatment condition was supposed as the Fe: BC ratio of 1:1, Fe amount of 6 mmol L−1, and the mole ratio of Fe to perfulfate of 1:1.
研究领域:
环境科学
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污染修复
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Yan Zhao,Min Song,Qi Cao,Peizhe Sun,Yonghao Chen,Fanyue Meng
CuFe 2 O 4 nanoparticles are decorated on biochar (BC) by modified sol-gel method to form the CuFe 2 O 4 @BC catalyst for persulfate (PS) activation in a wide pH range. The application of CuFe 2 O 4 @BC for o -nitrochlorobenzene degradation in soil was explored in this study. The mechanism of heterogeneous PS activation was comprehensively investigated. The synergistic effects between CuFe 2 O 4 and BC could enhance catalytic activity and stability, including well dispersed CuFe 2 O 4 species, efficient electron transfer and abundant oxygen functional groups. The superoxide radicals (O 2 − ) produced from CuFe 2 O 4 and BC could mediate Cu(I)/Cu(II) and Fe(II)/Fe(III) redox pairs on CuFe 2 O 4 @BC surface to activate PS, and then generating •OH and SO 4 − continuously. Moreover, the reaction intermediates are identified as well to elucidate the possible degradation pathways. These findings help to achieve more comprehensive understanding of the heterogeneous activation process of PS by CuFe 2 O 4 @BC catalyst.
研究领域:
环境科学
·
土壤修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2021
·
IF 4.237
Zhou Lan,Yangcheng Lu
In this work, a tubular reactor with a micromixer was introduced in attempt to enhance the amination reaction of 4-nitrochlorobenzene in terms of the process efficiency and safety. It was found that the reaction system containing a large excess of ammonia water can become homogeneous at high temperature. Thus, as both micromixing and the heat transfer performance were guaranteed, the set-up combining a micromixer and a microtube reactor enabled the reaction to exhibit homogeneous reaction characteristics, meeting the demands of efficiency and reliability. Furthermore, using a multi-channel sampling system connected behind the micromixer, the reaction kinetics were studied in a modified “stop flow” mode, which is adaptable for in-situ fast homogenization, high temperature, and high pressure. The reaction conditions were screened and a kinetic model was developed. Accordingly, we propose and verify a self-circulation strategy to reduce the burden of ammonia separation and recovery in a continuous tubular reactor system.
研究领域:
化学工程
·
反应工程
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 4
·833-838
·
IF 5.2
Zhou Lan,Yangcheng Lu
The reaction rate of the amination is affected by its electron-withdrawing group, however, there is currently a lack of quantitative research on the reaction rate of different substrates in experiments and simulations. In this work, taking the amination of nitrochlorobenzene as an example, the effects of various substrates, namely 4-nitrchlorobenzene, 4-chloro-3-(trifluoromethyl)nitrobenzene, 2,4-dinitrochloroben-zene, and 3,4-dichloronitrobenzene, on the reaction rate were systematically examined in a microflow system. Through the homogeneous continuous amination reaction strategy, the reaction kinetic characteristics of different substrates were obtained. The stronger the electron-withdrawing ability of the side chain group, the milder the reaction conditions and the shorter the reaction time. Furthermore, a density functional theory (DFT) simulation method was established to calculate the condensed local electrophilicity index (ωA). There is a good fitting on the relationship between the relative reaction rate of different substrates and the relative condensed local electrophilic index (ωAX − ωAH). It not only allows the prediction of the reaction rate of different substrates and the design of industrial production systems but also inspires us to enable more quick organic synthesis process development with the assistance of theoretic calculation.
研究领域:
有机化学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2020
·
IF 3.721
Haoran Wang,Ran Suo,Cuncun Zhang,Rongbin Li,Xu Shi,Yaqiong Liu,Wenxiu Wang,Jie Wang
A new method for determining the content of γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly, γ-EVG) using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) with precolumn derivatization by 2,4-Dinitrochlorobenzene (CDNB) was developed. The method exhibited satisfactory linear relationship ( R 2 = 0.9995) at concentrations ranging from 1.0 to 40.0 ng/mL. The limits of detection (LOD) and quantitation (LOQ) were 0.3 and 0.9 ng/mL, respectively. Recoveries of the target peptide in spiked samples were between 83.05% and 116.49%, showing the values of relative standard deviation (RSD) less than 10%. The intra-day and the inter-day precisions were calculated to be 7.13% and 8.54% ( n = 6), respectively. The validated approach was effectively applied to quantify the γ-EVG levels (0.13–0.38 μg/g) in different aquatic products. In conclusions, a sensitive, low-cost, convenient and reliable approach was developed for the detection of γ-EVG, which can serve as a potential tool for evaluating flavor peptide quality of aquatic products.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Renjie Deng,Kuiyi You,Wenjin Ni,Fangfang Zhao,Pingle Liu,He’an Luo
In this work, we developed a low-temperature and efficient approach for the highly selective preparation of valuable p -nitrochlorobenzene from the liquid-phase catalytic nitration of chlorobenzene with NO 2 in O 2 -Ac 2 O-Hβ composite system. The results demonstrated that the introduction of molecular oxygen remarkably enhanced the chlorobenzene conversion and the cooperation catalysis of Hβ zeolite and Ac 2 O envidently improved the selectivity to para -nitro product. Under the optimized reaction conditions, 93.6 % of the selectivity to p -nitrochlorobenzene with 84.0 % of chlorobenzene conversion was obtained, and the ratio of p -nitrochlorobenzene to o -nitrochlorobenzene could reach up to 20.3. Furthermore, the selectivity distribution of nitration products was reasonably explained by the density functional theory (DFT) calculation. Finally, the possible nitration reaction pathway of chlorobenzene with NO 2 was suggested in O 2 -Ac 2 O-Hβ composite catalytic system. The present work affords a new and mild nitration approach for highly selective preparation of valuable para -nitro products, and has potential industrial application prospects.
研究领域:
化学工程
·
催化
·
有机化学
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2023
·Vol. 49
·期 7
·3029-3044
·
IF 3.3
Deng Renjie,Cui Haishuai,Liu Meilin,Ni Wenjin,Tian Yao,Liu Huajie
Different solid superacid sulfated zirconium dioxide (SO 4 2− /ZrO 2 ) samples were successfully prepared by conventional and ultrasonic-assisted chemical precipitation process, and then, they were characterized by X-ray diffraction, Fourier transform infrared, thermal gravimetric analyzer (TGA), nitrogen adsorption–desorption, ammonia temperature programmed desorption (NH 3 -TPD) and pyridine adsorbs Fourier transform infrared. The results of characterizations indicate that the sulfonic acid group is successfully introduced, and the acidity and surface area of sulfated sample can be increased by using ultrasonic method. Furthermore, this ultrasonic-assisted catalyst was used for the chlorobenzene nitration using nitrogen dioxide (NO 2 ) as nitrating agent. The catalyst shows excellent catalytic activity and reusability for the nitration of chlorobenzene giving high para -selectivity. In the optimal reaction conditions, the conversion of chlorobenzene can reach 85.2% with 88.5% selectivity to para- nitrochlorobenzene ( p -NCB). Furthermore, the reaction mechanism was proposed by combination of experimental results and theoretical calculations. The present work provides an easy-to-implement, mild and environmentally friendly approach for the efficient preparation of valuable p -NCB, which has extensive industrial application prospects. Graphical abstract
研究领域:
催化
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有机化学
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材料科学
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化学合成
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环境化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Fanyue Meng,Chenbin Lin,Bing Song,Lei Yu,Yan Zhao,Zejian Zhi,Min Song
This study employed a self-designed underwater arc discharge (UAD) plasma reactor, which combined advanced oxidation process (Fe 2 O 3 -CoFe 2 O 4 /PMS) and low-temperature plasma technology to efficiently degrade refractory organic pollutants (i.e. phenol, p-chlorophenol, p-nitrochlorobenzene). The results illustrated that the plasma/PMS/Fe 2 O 3 -CoFe 2 O 4 system possessed high degradation efficiency and TOC removal rate towards three target pollutants (phenol: 99.8%, 96.12%; 4-CP: 98.4%, 86.48%; p-NCB: 99.9%, 88.31%). With the help of in-situ variable temperature EPR and Indigo colorimetry method, ·OH, SO 4 ·- , O 2 ·- , 1 O 2 and O 3 were identified as the main reactive oxygen species (ROS) for the degradation of target pollutants, revealing the synergistic catalytic mechanism between plasma and Fe 2 O 3 -CoFe 2 O 4 for PMS activation and inferring the degradation pathways of target pollutants. The results confirmed that the plasma/PMS/Fe 2 O 3 -CoFe 2 O 4 system was feasible for the degradation of refractory organic pollutants, has the advantages of high efficiency and low energy consumption, and could provide an effective strategy for the treatment of refractory organic pollutants in groundwater/soil.
研究领域:
环境科学
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化学工程
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
BIOORGANIC CHEMISTRY
·
2024
·
IF 4.5
Xiao-Fang Zhang,Hong-Fei Li,Hui Liu,Fang-Lu Wei,Jiao-Xian Du,Ji-Kai Liu,Juan He,Tao Feng
Twenty-nine sesquiterpenoids, including pseudoguaiane-type ( 1 – 11 ), eudesmane-type ( 12 – 23 ), and carabrane-type ( 24 – 29 ), have been identified from the plant Carpesium abrotanoides . Of them, compounds 1 – 4 , 12 – 15 , and 24 – 27 , namely carpabrotins A–L, are twelve previously undescribed ones. Compound 3 possessed a pseudoguaiane backbone with a rearrangement modification at C-11, C-12 and C-13, while compound 4 suffered a carbon bond break between the C-4 and C-5 to form a rare 4,5- seco -pseudoguaiane lactone. Compounds 1 – 3 , 5 , 13 – 16 and 25 – 27 exhibited anti-inflammatory activity by inhibiting NO production in LPS-induced RAW264.7 macrophages with IC 50 values less than 40 μM, while compounds 1 , 2 , 5 , 13 , 14 , 16 , and 25 – 27 showed significant inhibitory activity comparable to that of dexamethasone. The anti-atopic dermatitis (AD) effects of compounds 5 and 16 were tested according to 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in KM mice, and the results revealed that the major products 5 and 16 improved the histological features of AD-like skin lesions and mast cell infiltration in mice. This study suggested that sesquiterpenoids in C. abrotanoides should play a key role in its anti-inflammatory use.
研究领域:
药理学
·
植物化学
·
炎症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MEDIATORS OF INFLAMMATION
·
2022
·
IF 4.529
Hao Xiong,Jin Yang,Tao Liu,Guangren Liu,Yongzhi Han,Xiuqin Dong
Atopic dermatitis (AD) is a chronic skin inflammatory disease associated with immune abnormalities and disrupted skin barrier function. Mesenchymal stem cells (MSCs) have been suggested as an alternative therapeutic option in AD. Stem cells from human exfoliated deciduous teeth (SHEDs) are a unique postnatal stem cell population with high immunomodulatory properties. The aim of this study was to explore the effects of SHEDs on AD in the BALB/c mouse model induced by 2,4-dinitrochlorobenzene (DNCB). SHEDs were administrated intravenously or subcutaneously, and clinical severity, histopathological findings, skin barrier function, and organ indexes were evaluated. Skin tissue cytokine mRNA levels and serum cytokine protein levels were further analysed. SHED administration significantly alleviated AD clinical severity, including dermatitis scores, ear thickness, scratching behaviour, and infiltration of mast cells. In addition, disrupted skin barrier function and enlarged spleens were restored by SHED administration. Further, SHED treatment reduced the levels of IgE, IgG1, and thymic stromal lymphopoietin (TSLP) in the serum and the modulated expression of Th1-, Th2-, and Th17-associated cytokines in skin lesions. In conclusion, SHEDs attenuated AD-like skin lesions in mice by modulating the immune balance and skin barrier function. SHEDs could be a potential new treatment agent for AD.
研究领域:
免疫学
·
皮肤病学
·
干细胞研究
·
炎症性疾病
✓ 已验证
DOI
PubMed
高影响因子
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