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Ozonation of the 5-fluorouracil anticancer drug and its prodrug capecitabine: Reaction kinetics, oxidationmechanisms, and residual toxicity

Siyu Chen, Lee Blaney, Ping Chen, Shanshan Deng, Mamatha Hopanna, Yixiang Bao, Gang Yu

《环境科学与工程前沿（英文）》 2019年 第13卷 第4期 doi: 10.1007/s11783-019-1143-2

摘要：

Specific second-order rate constants were determined for 5-FU and CAP with ozone.

Reaction sites were confirmed by kinetics, Fukui analysis, and products.

The olefin moiety was the main ozone reaction site for 5-FU and CAP.

Carboxylic acids comprised most of the residual TOC for 5-FU.

Ozonation removed the toxicity associated with 5-FU and products but not CAP.

关键词： Ozone     5-fluorouracil     Capecitabine     Hydroxyl radicals     Chemotherapy agents     Toxicity    

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Redox reactions of iron and manganese oxides in complex systems

Jianzhi Huang, Huichun Zhang

《环境科学与工程前沿（英文）》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1255-8

摘要： • Mechanisms of redox reactions of Fe- and Mn-oxides were discussed. • Oxidative reactions of Mn- and Fe-oxides in complex systems were reviewed. • Reductive reaction of Fe(II)/iron oxides in complex systems was examined. • Future research on examining the redox reactivity in complex systems was suggested. Conspectus Redox reactions of Fe- and Mn-oxides play important roles in the fate and transformation of many contaminants in natural environments. Due to experimental and analytical challenges associated with complex environments, there has been a limited understanding of the reaction kinetics and mechanisms in actual environmental systems, and most of the studies so far have only focused on simple model systems. To bridge the gap between simple model systems and complex environmental systems, it is necessary to increase the complexity of model systems and examine both the involved interaction mechanisms and how the interactions affected contaminant transformation. In this Account, we primarily focused on (1) the oxidative reactivity of Mn- and Fe-oxides and (2) the reductive reactivity of Fe(II)/iron oxides in complex model systems toward contaminant degradation. The effects of common metal ions such as Mn2+ , Ca2+, Ni2+, Cr3+ and Cu2+, ligands such as small anionic ligands and natural organic matter (NOM), and second metal oxides such as Al, Si and Ti oxides on the redox reactivity of the systems are briefly summarized.

关键词： Iron oxides     manganese oxides     reduction     oxidation     complex systems     reaction kinetics and mechanisms    

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Product identification and toxicity change during oxidation of methotrexate by ferrate and permanganate in water

《环境科学与工程前沿（英文）》 2022年 第16卷 第7期 doi: 10.1007/s11783-021-1501-8

摘要：

• Oxidation of methotrexate by high-valent metal-oxo species was first explored.

关键词： Anticancer drugs     High-valent metal-oxo species     Oxidation kinetics     Reaction mechanisms     Multi-endpoint toxicity    

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Modeling the aqueous reaction kinetics of estriol with ferrate

Cong LI, Naiyun GAO

《化学科学与工程前沿（英文）》 2009年 第3卷 第1期   页码 39-45 doi: 10.1007/s11705-009-0098-4

摘要： In this study the aqueous oxidation kinetics of estriol (E3) by potassium ferrate (K FeO ), a chemical for its strong oxidizing power and for producing a coagulant from its reduced state (i.e. Fe(III)), was evaluated in the range of pH 8-12 with different molar ratios of the reactants. As the degree of Fe(VI) protonation varies with the solution pH, it was found that a first order model was not suitable to describe the oxidation reaction. This paper describes a theoretical representation that closely models the reaction kinetics of E3 and ferrate. From this modeling, the reaction rates of HFe and Fe with E3 have been determined. The results show that the reactivity of HFe with dissociated and undissociated E3 is greater than that of Fe , and that E3 is more reactive in its dissociated state.

关键词： ferrate     estriol     endocrine disruptor     kinetics     oxidation    

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Theoretical insights into influence of additives on sulfamethoxazole crystal growth kinetics and mechanisms

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1503-1515 doi: 10.1007/s11705-022-2294-4

摘要： In this work, the influence of the initial chemical potential gradient, stirring speed, and polymer type on sulfamethoxazole (SMX) crystal growth kinetics was systematically investigated through density functional theory (DFT) calculations, experimental measurements and the two-step chemical potential gradient model. To investigate the influence of different conditions on the thermodynamic driving force of SMX crystal growth, SMX solubilities in different polymer solutions were studied. Four model polymers effectively improved SMX solubility. It was further found that polyvinylpyrrolidone (PVP) and hydroxypropyl methyl cellulose (HPMC) played a crucial role in inhibiting SMX crystal growth. However, polyethylene glycol (PEG) promoted SMX crystal growth. The effect of the polymer on the crystal growth mechanisms of SMX was further analyzed by the two-step chemical potential gradient model. In the system containing PEG 6000, crystal growth is dominated by the surface reaction. However, in the system containing PEG 20000, crystal growth is dominated by both the surface reaction and diffusion. In addition, DFT calculations results showed that HPMC and PVP could form strong and stable binding energies with SMX, indicating that PVP and HPMC had the potential ability to inhibit SMX crystal growth.

关键词： insoluble drugs     polymer     inhibition crystallization     crystal growth kinetics     DFT calculations    

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Influence of extracellular polymeric substances from activated sludge on the aggregation kinetics of

《环境科学与工程前沿（英文）》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1450-2

摘要：

• The NPs aggregation in the electrolyte solution is consistent with the DLVO theory.

关键词： Silver nanoparticles     Silver sulfide nanoparticles     Extracellular polymeric substances     Aggregation kinetics     Influence mechanisms    

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Kinetics of pozzolanic reaction for preparation of flue gas desulfurizer from fly ash and Ca(OH)2

WANG Jingang, HU Jinbang, WANG Daobin, DUAN Zhenya

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 266-270 doi: 10.1007/s11705-007-0048-y

摘要： A kinetic model of the pozzolanic reaction for the preparation of flue gas desulfurizers from fly ash and Ca(OH) was deduced on the basis of solid phase reaction kinetic theory. Kinetic expressions and parameters were obtained and verified by experiment. A comparison of calculated results with experimental results showed that precision in kinetic expressions was good. The apparent reaction rate constants of the pozzolanic reaction could be raised by increasing the specific surface area of fly ash and the hydration temperature, and by using a suitable additive.

关键词： comparison     calculated     pozzolanic reaction     precision     preparation    

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Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

Jiajun CHEN , Hao WANG , Na ZHANG ,

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 313-319 doi: 10.1007/s11783-009-0025-4

摘要： This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account the impact of leachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model was modified by the introduction of the outflow function and the organic acid conversion coefficient in order to represent the in-situ condition of nutrient loss through leachate. Laboratory experiments were carried out to simulate the impact of leachate recirculation and verify the modified FKTSR model. The model calibration was then calculated by using the experimental data. The results suggested that the new model was in line with the experimental data. The main parameters of the modified FKTSR model, including the LFG production potential (), the reaction rate constant in the first stage (), and the reaction rate constant in the second stage () of 64.746 L, 0.202 d, and 0.338 d, respectively, were comparable to the old ones of 42.069 L, 0.231 d, and 0.231 d. The new model is better able to explain the mechanisms involved in LFG generation.

关键词： landfill gas (LFG)     generation rate model     first-order kinetics     two-stage reaction     outflow function    

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Events and reaction mechanisms during the synthesis of an Al

M. ABDELLAHI, M. ZAKERI, H. BAHMANPOUR

《化学科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 123-129 doi: 10.1007/s11705-013-1325-6

摘要： An Al O -TiB nanocomposite was successfully synthesized by the high energy ball milling of Al, B O and TiO . The structures of the powdered particles formed at different milling times were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermodynamic calculations showed that the composite formed in two steps via highly exothermic mechanically induced self-sustaining reactions (MSRs). The composite started to form at milling times of 9–10 h but the reaction was not complete. The remaining starting materials were consumed by increasing the milling time to 15 h. The XRD patterns of the annealed powders showed that aluminum borate is one of the intermediate products and that it is consumed at higher temperatures. Heat treatment of the 6-h milled sample at 1100 C led to a complete formation of the composite. Increasing the milling time to 15 h led to a refining of the crystallite sizes. A nanocomposite powder with a mean crystallite size of 35–40 nm was obtained after milling for 15 h.

关键词： ball milling     nanocomposite     Al2O3     TiB2    

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Sorption mechanisms of diphenylarsinic acid on natural magnetite and siderite: Evidence from sorptionkinetics, sequential extraction and extended X-ray absorption fine-structure spectroscopy analysis

《环境科学与工程前沿（英文）》 2022年 第16卷 第9期 doi: 10.1007/s11783-022-1547-2

摘要：

• DPAA sorption followed pseudo-secondary and intra-particle diffusion models.

关键词： Diphenylarsinic acid (DPAA)     Sorption     Magnetite     Siderite     Sequential extraction     EXAFS    

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Effects of support acidity on the reaction mechanisms of selective catalytic reduction of NO by CH

Shicheng XU, Junhua LI, Dong YANG, Jiming HAO

《环境科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 186-193 doi: 10.1007/s11783-009-0016-5

摘要： The reaction mechanisms of selective catalytic reduction (SCR) of nitric oxide (NO) by methane (CH ) over solid superacid-based catalysts were proposed and testified by DRIFTS studies on transient reaction as well as by kinetic models. Catalysts derived from different supports would lead to different reaction pathways, and the acidity of solid superacid played an important role in determining the reaction mechanisms and the catalytic activities. Higher ratios of Br?nsted acid sites to Lewis acid sites would lead to stronger oxidation of methane and then could facilitate the step of methane activation. Strong Br?nsted acid sites would not necessarily lead to better catalytic performance, however, since the active surface NO species and the corresponding reaction routes were determined by the overall acidity strength of the support. The reaction routes where NO moiety was engaged as an important intermediate involved moderate oxidation of methane, the rate of which could determine the overall activity. The reaction involving NO moiety was likely to be determined by the step of reduction of NO. Therefore, to enhance the SCR activity of solid superacid catalysts, reactions between appropriate couples of active NO species and activated hydrocarbon intermediates should be realized by modification of the support acidity.

关键词： selective catalytic reduction (SCR)     nitric oxide (NO)     methane     support acidity     Br?nsted acid sites     NOy species    

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Kinetics of oxidation of dimethyl trisulfide by potassium permanganate in drinking water

Xiaoyan MA, Shifei HU, Hongyu WANG, Jun LI, Jing HUANG, Yun ZHANG, Weigang LU, Qingsong LI

《环境科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 171-176 doi: 10.1007/s11783-011-0319-1

摘要： Metabolites of algae such as geosmin, 2-methylisoborneol etc. are reported to induce pungent odors into drinking water and attract additional scientific attention. Recently, in China, taste and odor outbreaks in drinking water supply have become increasingly common. In source water affected by eutrophication, dimethyl trisulfide, speculated to be produced by decayed algae, was found to be the source of taste and odor issues and can be removed effectively by usual oxidation agents. In this experimental study, batch scale tests were carried out focusing on the removal of dimethyl trisulfide. Reaction kinetics of dimethyl trisulfide oxidized by potassium permanganate in water had been studied; influence factors such as pH, organic substrate, other existed taste, and odor contaminant in equivalent concentration were also discussed. Results showed that dimethyl trisulfide can be removed by potassium permanganate efficiently; the ratio can reach more than 70% with oxidant dosage of 4 mg·L and contact time prolonged to 120 min. The dimethyl trisulfide decomposition followed a second-order kinetics pattern with a rate constant = 0.00213 L·(min·mg) . Typically, the degradation rate of dimethyl trisulfide was increased with the increasing KMnO dosage, but dramatically dropped with the increasing levels of humic acid (1.8–4.5 mg·L ) and other odor-causing compounds (e.g. -cyclocitral, 0–1886.0 μg·L ). Solution pH (5.2–9.0) and initial dimethyl trisulfide concentration did not significantly affected the degradation. This study demonstrates that KMnO oxidation is an effective option to remove dimethyl trisulfide from water.

关键词： odor and taste     oxidation reaction     reaction kinetics     water treatment    

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Simultaneous removal of trihalomethanes by bimetallic Ag/Zn: kinetics study

Ahmed H A DABWAN, Satoshi KANECO, Hideyuki KATSUMATA, Kiyoyuki EGUSA, Tohru SUZUKI, Kiyohisa OHTA,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 322-327 doi: 10.1007/s11705-009-0261-y

摘要： In the present work, bimetallic silver/zinc was applied into the degradation of trihalomethanes, THMs: CHCl, CHBrCl, CHBrCl, and CHBr. The kinetics reaction rates and removal efficiencies of the THM compound mixtures, in the aqueous solutions, were investigated. Batch experiments were conducted under mild conditions, ambient temperature, and pressure. The primary degradation reaction followed a pseudo-first-order kinetic law. The first-order rate constants and the degradation efficiencies followed the decreasing order of CHBr>CHBrCl>CHBrCl>CHCl. The bond dissociation energy and hydrophilic/hydrophobic characteristics of the THM compounds may become the most important parameters affecting the degradation kinetics and efficiency by bimetallic Ag/Zn.

关键词： reaction     first-order     dissociation     degradation reaction     aqueous    

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Kinetics and mechanisms of reactions for hydrated electron with chlorinated benzenes in aqueous solution

Haixia YUAN,Huxiang PAN,Jin SHI,Hongjing LI,Wenbo DONG

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 583-590 doi: 10.1007/s11783-014-0691-8

摘要： The reactions between chlorinated benzenes (CBzs) and hydrated electron ( ) were investigated by the electron beam (EB) and laser flash photolysis (LFP) experiments. Under the EB irradiation, the effects of irradiation dose, initial concentration and the number of Cl atoms on the removal efficiencies were further examined. At 10 kGy, the removal efficiencies of mono-CB, 1,3-diCB, 1,2-diCB and 1,4-diCB were 41.2%, 87.2%, 84.0%, and 84.1%, respectively. While irradiation dose was 50 kGy, the removal efficiencies increased to 47.4%, 95.8%, 95.0%, and 95.2%, respectively. Irradiation of CBzs solutions has shown that the higher the initial concentration, the lower the percentage of CBzs removal. In addition to this, the dechlorination efficiencies of 1,2-dichlorobenzene (1,2-diCB), 1,3-dichlorobenzene (1,3-diCB) and 1,4-dichlorobenzene (1,4-diCB) were much higher than that of chlorobenzene (mono-CB). The kinetics of the reactions was achieved with nanosecond LFP. The rate constants of second-order reaction between with mono-CB, 1,2-diCB, 1,3-diCB and 1,4-diCB were (5.3±0.4) × 10 , (4.76±0.1) × 10 , (1.01±0.1) × 10 and (3.29±0.2) × 10 L·mol ·s , respectively. Density functional theory (DFT) calculations were performed to determine the optical properties of unstable CBzs anion radicals, and the main absorption peaks lied in the range of 300–550 nm. The primary reaction pathway of CBzs with was gradual dechlorination, and the major products were Cl and benzene (CBzs(-Cl )). Furthermore, biphenyl (or chlorobiphenyl) was observed during the LFP, which was probably formed by recombination of benzene radicals.

关键词： chlorinated benzenes     hydrated electron     electron beam     laser flash photolysis    

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Reaction kinetics and internal diffusion of Zhundong char gasification with CO

Yun Liu, Jiangyuan Qu, Xuehui Wu, Kai Zhang, Yuan Zhang

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 373-383 doi: 10.1007/s11705-020-1949-2

摘要： Mass transfer usually affects the rate of chemical reactions in coal. The effect of internal diffusion on char gasification with CO in the temperature range from 1123 K to 1273 K was investigated via thermo-gravimetric analysis and assessment of char morphology features. The results revealed that the effect of internal diffusion on the initial reaction rate was more significant with an increase of particle size, due to the concentration gradient of the gasification agent within the solid particles. In the early stage of gasification, the generation of new micropores and the opening of closed pores led to an increase in specific surface area. As the reaction proceeded, the openings were gradually expanded and the specific surface area continued to increase. However, with further reaction, disappearance of edge pores, melting and collapse of the pore structure led to a decrease in specific surface area. The intrinsic activation energy and reaction order based on the th-order model were 157.67 kJ∙mol and 0.36, respectively. Thus, temperature zones corresponding to chemical reaction and diffusion control were identified. Moreover, the calculated effectiveness factor provided a quantitative estimation of internal diffusion in the initial stage.

关键词： coal char     CO2 gasification     internal diffusion     pore evolution    

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标题 作者 时间 类型 操作

Ozonation of the 5-fluorouracil anticancer drug and its prodrug capecitabine: Reaction kinetics, oxidationmechanisms, and residual toxicity

Siyu Chen, Lee Blaney, Ping Chen, Shanshan Deng, Mamatha Hopanna, Yixiang Bao, Gang Yu

期刊论文

Redox reactions of iron and manganese oxides in complex systems

Jianzhi Huang, Huichun Zhang

期刊论文

Product identification and toxicity change during oxidation of methotrexate by ferrate and permanganate in water

期刊论文

Modeling the aqueous reaction kinetics of estriol with ferrate

Cong LI, Naiyun GAO

期刊论文

Theoretical insights into influence of additives on sulfamethoxazole crystal growth kinetics and mechanisms

期刊论文

Influence of extracellular polymeric substances from activated sludge on the aggregation kinetics of

期刊论文

Kinetics of pozzolanic reaction for preparation of flue gas desulfurizer from fly ash and Ca(OH)2

WANG Jingang, HU Jinbang, WANG Daobin, DUAN Zhenya

期刊论文

Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

Jiajun CHEN , Hao WANG , Na ZHANG ,

期刊论文

Events and reaction mechanisms during the synthesis of an Al

M. ABDELLAHI, M. ZAKERI, H. BAHMANPOUR

期刊论文

Sorption mechanisms of diphenylarsinic acid on natural magnetite and siderite: Evidence from sorptionkinetics, sequential extraction and extended X-ray absorption fine-structure spectroscopy analysis

期刊论文

Effects of support acidity on the reaction mechanisms of selective catalytic reduction of NO by CH

Shicheng XU, Junhua LI, Dong YANG, Jiming HAO

期刊论文

Kinetics of oxidation of dimethyl trisulfide by potassium permanganate in drinking water

Xiaoyan MA, Shifei HU, Hongyu WANG, Jun LI, Jing HUANG, Yun ZHANG, Weigang LU, Qingsong LI

期刊论文

Simultaneous removal of trihalomethanes by bimetallic Ag/Zn: kinetics study

Ahmed H A DABWAN, Satoshi KANECO, Hideyuki KATSUMATA, Kiyoyuki EGUSA, Tohru SUZUKI, Kiyohisa OHTA,

期刊论文

Kinetics and mechanisms of reactions for hydrated electron with chlorinated benzenes in aqueous solution

Haixia YUAN,Huxiang PAN,Jin SHI,Hongjing LI,Wenbo DONG

期刊论文

Reaction kinetics and internal diffusion of Zhundong char gasification with CO

Yun Liu, Jiangyuan Qu, Xuehui Wu, Kai Zhang, Yuan Zhang

期刊论文