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

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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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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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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Biodegradation of trace pharmaceutical substances in wastewater by a membrane bioreactor

Longli BO, Taro URASE, Xiaochang WANG

《环境科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 236-240 doi: 10.1007/s11783-009-0004-9

摘要： The biodegradation of selected pharmaceutical micropollutants, including two pharmaceuticals with argued biodegradation, was studied by a lab-scale membrane bioreactor. The reaction kinetics and affecting factors were also investigated in this paper. Clofibric acid (CA) with contradictive biodegradation reported was degraded almost completely at different hydraulic retention times (HRTs) after adaptation to microorganisms. The biodegradation of CA was disturbed at low pH operation, while the activity of microorganisms recovered again after pH adjustment to neutral condition. Ibuprofen (IBP) degraded under neutral and acidic conditions. Removals of IBP and CA were zero-order and first-order reactions under high and low initial concentrations, respectively. Carbamazepine and diclofenac were not degraded regardless of HRTs and pH.

关键词： pharmaceuticals     membrane bioreactor     activated sludge     reaction kinetics    

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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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Characterization of value-added chemicals derived from the thermal hydrolysis and wet oxidation of sewage sludge

Milan Malhotra, Anurag Garg

《环境科学与工程前沿（英文）》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1305-2

摘要： Abstract • Hydrothermal treatment can greatly improve resource recovery from sewage sludge. • tCOD removal during WO was ~55% compared with ~23% after TH. • TOC solubilization during hydrothermal treatment followed first-order kinetics. • Solids and carbon balance confirmed loss of organics during thermal hydrolysis. • Reaction pathways for thermal hydrolysis and wet oxidation are proposed. We evaluated the effect of hydrothermal pretreatments, i.e., thermal hydrolysis (TH) and wet oxidation (WO) on sewage sludge to promote resource recovery. The hydrothermal processes were performed under mild temperature conditions (140°C–180°C) in a high pressure reactor. The reaction in acidic environment (pH= 3.3) suppressed the formation of the color imparting undesirable Maillard’s compounds. The oxidative conditions resulted in higher volatile suspended solids (VSS) reduction (~90%) and chemical oxygen demand (COD) removal (~55%) whereas TH caused VSS and COD removals of ~65% and ~27%, respectively at a temperature of 180°C. During TH, the concentrations of carbohydrates and proteins in treated sludge were 400–1000 mg/L and 1500–2500 mg/L, respectively. Whereas, WO resulted in solids solubilization followed by oxidative degradation of organics into smaller molecular weight carboxylic acids such as acetic acid (~400–500 mg/L). Based on sludge transformation products generated during the hydrothermal pretreatments, simplified reaction pathways are predicted. Finally, the application of macromolecules (such as proteins), VFAs and nutrients present in the treated sludge are also discussed. The future study should focus on the development of economic recovery methods for various value-added compounds.

关键词： Hydrothermal pretreatment     Reaction kinetics     Reaction pathway     Sewage sludge     Thermal hydrolysis     Wet oxidation    

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Reaction kinetics of CaC

Renxing Wang,Zhenyu Liu,Leiming Ji,Xiaojin Guo,Xi Lin,Junfei Wu,Qingya Liu

《化学科学与工程前沿（英文）》 2016年 第10卷 第4期   页码 517-525 doi: 10.1007/s11705-016-1585-z

摘要： The production of CaC from coke/lime powders and compressed powder pellets are low cost and fast processes. A number of studies have reported the reaction kinetics of these reactions but they are still not well understood and the proposed kinetic models are not comparable due to differences in the reaction conditions. Therefore the reaction behavior of CaO/C powders (0.074 mm) and cubes (5 mm × 5 mm × (4.6–5.1) mm) compressed from a mixture of powders have been studied using thermal gravimetric analysis (TGA) at 1700– 1850 °C. Kinetic models were obtained from the TGA data using isoconversional and model-fitting methods. The reaction rates for the compressed feeds were lower than those for the powder feeds. This is due to the reduced surface area of the compressed samples which inhibits heat transfer from the surrounding environment (or the heating source) to the sample. The compression pressure had little influence on the reaction rate. The reaction kinetics of both the powder and the compressed feeds can be described by the contracting volume model ( ) = 3(1− ) , where is the conversion rate of reactant. The apparent activation energy and pre-exponential factor of the powder feed were estimated to 346–354 kJ?mol and 5.9 × 10 min , respectively, whereas those of the compressed feed were 305–327 kJ?mol and 3.6 × 10 min , respectively.

关键词： calcium carbide     kinetic model     activation energy     pre-exponential factor    

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Kinetics of halogen-exchange fluorination of 2,6-dichlorobenzaldehyde

LIANG Zhengyong, LI Bindong, FENG Chao

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 59-62 doi: 10.1007/s11705-008-0008-1

摘要： Under the conditions of phase transfer catalysis and nitrobenzene as the solvent, the halogen-exchange fluorination of 2,6-dichlorobenzaldehyde using KF as fluorinating agent was studied. The kinetics was investigated and the reaction rate constants were obtained under the optimum conditions of (KF):(2,6-dichlorobenzaldehyde):(PhPBr):n(acetone-furan crown ether) = 4:1:0.1:0.05 and temperatures of 433 K, 443 K, 453 K and 463 K. The results illustrated the activation energy of the first and the second step is 4.57 × 10 J·mol and 3.53 × 10 J·mol, respectively. The pre-exponential factor is 4.50 × 10 h and 1.08 × 10 h, respectively. Thus a reliable kinetics data could be obtained for further research.

关键词： reaction     solvent     transfer catalysis     activation     nitrobenzene    

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Kinetics and mechanism of nitrobenzene degradation by hydroxyl radicals-based ozonation process enhanced

Weizhou Jiao, Shengjuan Shao, Peizhen Yang, Kechang Gao, Youzhi Liu

《化学科学与工程前沿（英文）》 2021年 第15卷 第5期   页码 1197-1205 doi: 10.1007/s11705-020-1998-6

摘要： This study investigated the indirect oxidation of nitrobenzene (NB) by hydroxyl radicals (·OH) in a rotating packed bed (RPB) using competitive kinetics method with -nitrochlorobenzene as a reference compound. The rate constants of NB with ·OH are calculated to be between (1.465±0.113) × 10 L/(mol·s) and (2.497±0.192) × 10 L/(mol·s). The experimental data are fitted by the modified Arrhenius equation, where the activation energy is 4877.74 J/mol, the order of NB concentration, rotation speed, and initial pH is 0.2425, 0.1400 and 0.0167, respectively. The ozonation process of NB could be enhanced by RPB, which is especially effective for highly concentrated NB-containing wastewater under alkaline conditions. The high gravity technology can accelerate ozone mass transfer and self-decomposition of ozone to produce more ·OH, resulting in an increase in the indirect oxidation rate of NB by ·OH and consequently effective degradation of NB in wastewater.

关键词： high gravity technology     hydroxyl radicals     nitrobenzene     reaction kinetics    

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Silver-catalyzed bioleaching for raw low-grade copper sulphide ores

Tianlong DENG, Yafei GUO, Mengxia LIAO, Dongchan LI

《化学科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 250-254 doi: 10.1007/s11705-009-0049-0

摘要： This research was conducted to investigate the biooxidation and copper dissolution from raw low-grade refractory copper sulphide ores located in the Xinjiang Autonomous Region of China using adapted bacteria. In order to accelerate the bioleaching rate, the adapted mixed bacteria and silver ion catalyst were tested in the leach columns at laboratory scale. The overall acid consumption was 4.3 kg sulphuric acid per kg of dissolved copper and was linearly related to the percent copper dissolution. The calculated copper dissolution rates obey the Shrinking Core Model. The relative activation energy of the whole biooxidative leaching stages was calculated to be 48.58 kJ/mol.

关键词： green process     biohydrometallurgy     bioleaching     reaction kinetics     sulphide ores    

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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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标题 作者 时间 类型 操作

Modeling the aqueous reaction kinetics of estriol with ferrate

Cong LI, Naiyun GAO

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

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

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

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

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

Biodegradation of trace pharmaceutical substances in wastewater by a membrane bioreactor

Longli BO, Taro URASE, Xiaochang WANG

期刊论文

Redox reactions of iron and manganese oxides in complex systems

Jianzhi Huang, Huichun Zhang

期刊论文

Characterization of value-added chemicals derived from the thermal hydrolysis and wet oxidation of sewage sludge

Milan Malhotra, Anurag Garg

期刊论文

Reaction kinetics of CaC

Renxing Wang,Zhenyu Liu,Leiming Ji,Xiaojin Guo,Xi Lin,Junfei Wu,Qingya Liu

期刊论文

Kinetics of halogen-exchange fluorination of 2,6-dichlorobenzaldehyde

LIANG Zhengyong, LI Bindong, FENG Chao

期刊论文

Kinetics and mechanism of nitrobenzene degradation by hydroxyl radicals-based ozonation process enhanced

Weizhou Jiao, Shengjuan Shao, Peizhen Yang, Kechang Gao, Youzhi Liu

期刊论文

Silver-catalyzed bioleaching for raw low-grade copper sulphide ores

Tianlong DENG, Yafei GUO, Mengxia LIAO, Dongchan LI

期刊论文

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

期刊论文