ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Bao-Jun Xu,Yao Lu,Nan Liu,Ying Chen,Min Liu,Qian-Yuan Wu,Ye Du
Periodate (PI) shows promising potential as an oxidant for wastewater treatment; however, its impact on the toxicity of wastewater remains unknown. Here, we found that with 100 μM PI addition, the cytotoxicity of wastewater increased from 4.8 to 7.6 mg-Phenol/L to 9.5 to 12.8 mg-Phenol/L, and genotoxicity increased from 0.3 to 0.9 μg-4-NQO/L. Interestingly, hypoiodous acid (HOI) was not detected during the reaction, and there was no observed increase in the concentration of total organic iodine (TOI). CHON components in dissolved organic matter changed most obviously in PI oxidation, which might serve as primary precursors for toxic byproducts. Cytotoxicity of typical nitrogen-containing precursors of tryptophan, lysine, phenylalanine, and tyrosine after PI oxidation increased from not detected to 14.7, 2.4, 4.1, and 3.2 mg-Phenol/L, respectively. Here, four nonhalogenated aromatic nitrogenous byproducts (N-DBPs) of 3-hydroxyquinoline, 4-hydroxyquinoline, benzopyridine, and benzopyrrole were confirmed using standards, and four byproducts such as 2-formylbenzonitrile were tentatively proposed. The cytotoxicity of the four confirmed byproducts was comparable to those known N-DBPs such as nitrosamines, suggesting attention should be given to these nonhalogenated but nitrogenous byproducts. The four confirmed byproducts were detected in two PI-treated wastewater samples with concentrations of 0.8, 0.98, 0.52, and 0.0038, and 18.28, 1.50, 0.57, and 0.0074 μg/L, respectively, with contributions less than 1.5% to the overall cytotoxicity. Further investigations are warranted to elucidate the primary drivers of toxicity in PI-treated wastewater.
研究领域:
环境科学
·
水处理
·
毒理学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Jiajia Ma,Zhiheng Ye,Jie Zhou,Zhong-Ting Hu,Qianqian Wang,Junliang Wang,Zhiyan Pan,Mian Hu
In this study, the influences of soybean straw (SS) to spirulina platensis (SP) mass ratios and pyrolysis temperature on the evolution properties of N-containing species in pyrolytic tri-products and the nitrogen migration mechanism and involved chemical reactions during the co-pyrolysis processes were comprehensively investigated. Results indicated that co-pyrolysis of SS ang SP significantly facilitated the transformation of nitrogen into N bio-oil and N char from N gas . Increasing the amount of SP led to a decrease in the concentration of NH 3 and HCN in N gas , while their concentrations increased gradually with temperature increasing. NH 3 and HCN formation was due to H radicals attacking the N-sites of N-heterocyclic, with NH 3 formation being more strongly influenced by this process. Regarding N char , increasing the ratio of SP enhanced nitrogen incorporation reactions and promoted formation of pyridinic-N and pyrrolic-N. Conversely, decreasing the ratio of SP enhanced hydrogenation and condensation reactions, which favored the formation of quaternary-N. With increasing temperature, protein-N decomposed significantly, while pyridinic-N, pyrrolic-N, and quaternary-N remained stable. Additionally, pyridinic-N can convert to quaternary-N at temperature > 500 °C. Increasing the SP ratio greatly decreased oxygenates content while increased that of N-containing compounds in N bio-oil . The content of heterocycle-N (34.31 %) and nitriles (9.22 %) in bio-oil peaked at a ratio of 1:3, attributed to SP promoted the condensation and diazotization cyclization reactions. Furthermore, increasing the reaction temperature (from 400 to 800 °C) significantly increased the yields of heterocycles-N, while the yields of amines and amides decreased sharply due to dehydration reaction. As analyzed above, the possible nitrogen migration mechanism and involved chemical reactions were elucidated. These findings provides insights for generating high value-added N-containing chemicals and N-doped carbon materials during N-rich pyrolysis.
研究领域:
能源与环境科学
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化学工程
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产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yang Bai,Fuxiang Feng,Lei Tian,Yankun Xiong,Yong Yang,Qiang Guo,Yuan Liu
To advance the direct coal liquefaction (DCL) technology by a “Catalytic cycle of hydrogen donor solvents” pathway, it was important for the iron-based DCL catalyst to be pre-sulfurized under a suitable condition. In this report, the effect of liquid medium in the slurry bed pre-sulfurization process on iron-based catalyst was studied. Catalysts were pre-sulfurized under a variety of liquid mediums including alkanes, aromatics and heteroatom-containing compounds and the activity were evaluated according to their performance on hydrogenation of naphthalene . It was observed that, the nitrogen-containing medium give rise to the significant negative influence on the catalytic activity (with only 2.5 %-15.3 % of naphthalene conversions). Multiple spectroscopic and microscopic analyses of catalysts exhibited that the decrease of S vacancies was mainly responsible for the low activity. It was due to the promotion effect on Fe 1-x S crystallization and troilite generation. S vacancies of the iron-based catalysts was considered as Lewis acid sites to catalyze the hydrogenation reaction. The new findings from this work is beneficial for the development and optimization of pre-sulfurization technology .
研究领域:
化学工程
·
催化科学
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DOI
高影响因子
Foods
·
2023
·Vol. 12
·期 7
·1371
·
IF 5.2
Jing Wang,Lina Qiao,Ruifang Wang,Ning Zhang,Yuping Liu,Haitao Chen,Jie Sun,Shuqi Wang,Yu Zhang
The Allium plant is widely used in cuisines around the world for its characteristic flavor. The general profile of the plant changes a lot and presents quite different smells after the frying process. In this work, five Allium plants and their fried oils were compared to find out how the frying process impacts the general flavor profile. The results of sensory analysis indicated that the frying process could substantially increase the flavor acceptability of fresh Allium plants. Meanwhile, according to gas chromatography-mass spectrometry (GC-MS) analysis, fewer volatile compounds were detected in fresh Allium plants than in their fried oils. Furthermore, contents of nitrogen-containing compounds (ranging from 0.17 μg/g to 268.97 μg/g), aldehydes (ranging from 71.82 μg/g to 1164.84 μg/g), and lactones (ranging from 0 μg/g to 12.38 μg/g) increased significantly. In addition, more aroma-active substances were identified in the fried Allium oils revealed by gas chromatography-olfactometry (GC-O) analysis. Sulfur-containing compounds were the most abundant in fresh Allium plants, whereas nitrogen-containing compounds dominated in fried oils. The thermal degradation of sugars, amino acids and lipids as well as interactions between carbohydrates, proteins, and fats during the frying process were thought to be the main contributors to these variations. Therefore, this research provides a theoretical basis for the quality control of onion oil flavor and promotes the further development of the onion plant industry. Consequently, the research provided a theoretical basis for the quality control of Allium oils’ flavor and promoted the further development of Allium plant industries.Keywords:Allium plants;frying process;flavor;aroma active compounds
研究领域:
食品科学
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植物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Nan Lu,Bin Liu,Zhengxin Peng,Jing Sui,Xiaofan Zhang,Yuting Ma,Renhong Li,Xiaoqing Yan
Rational design and fabrication of catalysts with excellent efficiency, high selectivity and outstanding stability is of great significance for the practical application of formic acid dehydrogenation into hydrogen gas. Herein, Pd catalysts with a narrow size distribution around 2.2 nm are deposited on the porous chitosan microspheres, which are produced by the polycondensation with Schiff base linkage. The Pd–N bond configuration is formed upon the abundant amino-group on the chitosan backbone with the surface anchoring Pd nanocluster. The surface charge is redistributed to generate high-valence Pd δ+ species due to the ligand-to-metal charge transfer between Pd and N, thus greatly improving the catalytic performance of formic acid dehydrogenation at room temperature and maintaining outstanding stability during 15 consecutive reaction cycles. The present work paves the way to the rational synthesis of Pd-based catalysts with tunable electronic states for practical purposes.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Chao Liu,Huiyan Zhang,Rui Xiao,Shubin Wu
Thermogravimetric characteristics of chitin and chitosan and their potentials to produce value-added organonitrogen chemicals were separately evaluated via TG/DSC-FTIR and Py-GC/MS. Results shown that chitin had the better thermal stability and higher activation energy than chitosan because of the abundant acetamido group. Furthermore, the dominated volatilization in active pyrolysis of chitin contributed to its endothermic property, whereas the charring in chitosan led to the exothermal. During fast pyrolysis, the acetamido group in chitin and chitosan was converted into acetic acid or acetamide. Typical products from chitosan pyrolysis were aza-heterocyclic chemicals, i.e. pyridines, pyrazines, and pyrroles, with the total selectivity of 50.50% at 600 °C. Herein, selectivity of pyrazine compounds was up to 22.99%. These aza-heterocyclic chemicals came from the nucleophilic addition reaction of primary amine and carbonyl. However, main reaction during chitin pyrolysis was ring-opening degradation, which led to the formation of acetamido chemicals, especially acetamido acetaldehyde with the highest selectivity of 27.27% at 450 °C. In summary, chitosan had the potential to produce aza-heterocyclic chemicals, and chitin to acetamido chemicals.
研究领域:
生物化学
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材料科学
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2025
·
IF 5
Wenxuan Huang,Wenbiao Liu,Yongming Zheng,Feng Rao,Lang Yang,Kaixi Jiang
In this study, four N-containing collectors were compared systematically to study the flotation selectivity, froth layer stability and economic cost in reverse flotation of silicate minerals from fluorapatite. The adsorption of collectors were studied by zeta potential and x-ray photoelectron spectroscopy (XPS) measurements. Froth stability of the slurries with collectors was characterized through froth image and water recovery analysis. The flotation of pure fluorapatite, quartz, mica and raw phosphate ore gave that oleyl amine (OA) and N-(2-hydroxyethyl)-dodecane amide (HEDA) had better selectivity than dodecyl amine (DDA). It was found that the physisorption of OA and HEDA associated with the silicate mineral surfaces through hydrophobic bonding to form hemimicelles. Interestingly in octyl-hydroxamic acid (OHA) flotation, the best selectivity in reverse flotation of silicate minerals from fluorapatite was obtained, because of the chemisorption of O atoms on Al atoms through chelating rings. For froth stability, OA and HEDA induced a denser froth layer than DDA. In OHA flotation slurry, the individual bubbles were larger and easier to coalesce, leading to the lowest water recoveries and froth stability. This study might provide a further understanding on the N-containing collectors in reverse flotation of silicate minerals from fluorapatite.
研究领域:
矿物加工工程
·
表面化学
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产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 20
·3636
·
IF 5.719
Jianchao Gong,Tingting Wang,Wei Zhang,Lin Han,Mingxiao Gao,Tianen Chen,Tao Shen,Yaxiong Ji
To explore the effect of spacer structure on the adsorption capability of organo-vermiculites (organo-Vts), a series of aza-containing gemini surfactants (5N, 7N and 8N) are applied to modify Na-vermiculite (Na-Vt). Large interlayer spacing, strong binding strength and high modifier availability are observed in organo-Vts, which endow them with superiority for the adsorption of 2-naphthol (2-NP) and bromophenol blue (BPB). The maximum adsorption capacities of 5N-Vt, 7N-Vt and 8N-Vt toward 2-NP/BPB are 142.08/364.49, 156.61/372.65 and 146.50/287.90 mg/g, respectively, with the adsorption processes well fit by the PSO model and Freundlich isotherm. The quicker adsorption equilibrium of 2-NP than BPB is due to the easier diffusion of smaller 2-NP molecules into the interlayer space of organo-Vts. Moreover, stable regeneration of 7N-Vt is verified, with feasibility in the binary-component system that is demonstrated. A combination of theoretical simulation and characterization is conducted to reveal the adsorption mechanism; the adsorption processes are mainly through partition processes, electrostatic interaction and functional interactions, in which the spacer structure affects the interlayer environment and adsorptive site distribution, whereas the adsorbate structure plays a role in the diffusion process and secondary intermolecular interactions. The results of this study demonstrate the versatile applicability of aza-based organo-Vts targeted at the removal of phenols and dyes as well as provide theoretical guidance for the structural optimization and mechanistic exploration of organo-Vt adsorbents.Keywords:organo-vermiculite;aza-containing gemini surfactant;2-Naphthol;bromophenol blue;adsorption
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Energies
·
2015
·Vol. 8
·期 11
·13021-13032
·
IF 2.072
Pan Gao,Lu Xue,Qiang Lu,Changqing Dong
To study the effects of inherent and external alkali and alkaline earth metallic species (AAEMs,i.e., K, Ca and Mg) on the behavior of N-containing species release during rice straw (RS) pyrolysis, different pretreatments were applied in numerous experiments. Results indicate that ammonia (NH3) and hydrogen cyanide (HCN) are the major N-containing species and that the yields of isocyanic acid (HNCO) and nitric oxide (NO) are relatively low. The removal of inhert AAEMs shifts N-containing species release to a high-temperature zone according to volatile release behavior because of the increase in activation energy. The formation selectivity of NH3, HNCO, and NO increases by demineralized pretreatment, whereas HCN selectivity decreases. The formation of HNCO is mainly affected by alkaline earth metal. N-containing species release occurs in low temperatures with the addition of external AAEMs. The activation energy of samples impregnated with CaCl2and MgCl2sharply decreases compared to the original RS. The total yields of N-containing species are reduced significantly in the presence of KCl, CaCl2, and MgCl2as additives. The inhibition ability of AAEMs follows the sequence MgCl2> CaCl2> KCl. The inhibition effect of MgCl2can be improved by solution immersion compared with solid powder mixing. The clean biomass pyrolysis and gasification technology with low N-containing species content may be developed according to the results.Keywords:pyrolysis;N-containing species;alkali and alkaline earth metals (AAEMs);formation selectivity;relative yield
研究领域:
能源与环境科学
·
化学工程
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产品关联
DOI
高影响因子
SURFACE AND INTERFACE ANALYSIS
·
2021
·Vol. 53
·期 12
·1027-1034
·
IF 1.607
Qi Chen,Renhui Zhang,Zhongyi He,Liping Xiong
N-containing heterocyclic compound (NCHC) was a common used green lubricant addictive due to their extreme pressure, antiwear and friction–reduction performance, and high thermal stability, and ethylene glycol (EG) as lubricant exhibited superior tribological performance, combining of NCHCs, which was a suitable candidate for further improving the tribosystems' tribological properties. Thus, in this work, the synergistic effect between EG and 2,4,6-Tris(2-pyridinyl)-s-triazine (TPT) on the tribological performance was explored coupling of the applied loads and rotational speed. The tribological tests showed that TPT played an important role in improving the tribological properties as sliding in TPT@EG; the formation of the tribofilms induced by tribochemical reaction was in charge of enhancing the tribosystem's lubrication performance sliding in TPT@EG.
研究领域:
材料科学
·
化学工程
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yang Zhang,Yucui Xu,Baoyou Shi,Xin Huang
Activated carbon adsorption has been identified as an effective technique for per- and polyfluoroalkyl substances (PFAS) removal. However, the role of nitrogen-containing functional groups and pore size on PFAS elimination is uncertain. Therefore, this study prepared a series of AC with different nitrogen groups and pore structures by thermal treatment with urea under different temperatures (denoted as AC400, AC600 and AC800). Their PFAS adsorption performance in ultrapure and real water were investigated to identify the contribution of different nitrogen groups and pore structures. The adsorption experiment indicated that the modified AC800 with high proportion of pyridine nitrogen and medium pore volume achieved the best performance in ultrapure water due to the electrostatic interaction. However, in the real water contained dissolved organic matter (DOM), rather than AC800, AC600 with large mesopore volume exhibited the maximum adsorption capacity and kinetic due to its better inhabitation of pore blockage by DOM. It could be inferred that the electrostatic attraction force was more important in PFAS adsorption in ultrapure water, but in real water the mesopore volume was more critical due to the pore blockage by DOM. This study can provide guidance and implications for selection and development of future PFAS adsorption carbon-based material.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 22
·12953-12961
·
IF 3.119
Yunfeng Liu,Zhengsong Qiu,Hanyi Zhong,Xin Zhao,Weian Huang,Xijin Xing
Solvent extraction is commonly used to separate mixtures of hydrocarbons and their derivatives, and solvent choice is strongly influenced by the affinity to the target component, cost and safety. Nitrogen-containing switchable solvents can switch from water-immiscible form to water-miscible bicarbonate salts when CO2 is injected and back to water-immiscible form when N2 is injected. Switchable solvents, as a type of recyclable green solvent, can be used not only to separate such mixtures but also to reduce process costs. Herein, four switchable solvents, namely, dipropylamine, di-sec-butylamine, N,N-dimethylcyclohexylamine (CyNMe2), and N,N,N′,N′-tetraethyl-1,3-propanediamine (TEPDA), were employed to separate benzene/cyclohexane, ethyl acetate/acetonitrile, and ethyl acetate/n-heptane mixtures, and the corresponding partition and selectivity coefficients were determined. In all cases, separation selectivity increased in the order of dipropylamine < di-sec-butylamine < CyNMe2 < TEPDA, i.e., TEPDA was best suited for the separation of hydrocarbons and their derivatives. In addition, cycling experiments revealed that the TEPDA can be re-used at least 15 times and was well suited for industrial applications. In the end, the mechanism of the separation was put forward.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）