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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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Simulation analysis of methanol flash distillation circulation process in biodiesel production with supercritical

Zhengjiao TANG, Cunwen WANG, Weiguo WANG, Jia GUO, Yuanxin WU, Jinfang CHEN, Yigang DING

《能源前沿（英文）》 2011年 第5卷 第1期   页码 93-97 doi: 10.1007/s11708-010-0028-7

摘要： High methanol-to-oil ratio is required to obtain a high conversion of oil for the production of biodiesel with supercritical methanol. Recovering the methanol of a stream issuing from a transesterification supercritical reactor by flash distillation instead of evaporation was analyzed. The one-stage and two-stage flash distillation processes were presented and compared. The difference of the recovery percentage of methanol of the above two flash processes is less than 0.5% and the methanol concentration in the vapor for the one-stage process decreases rapidly when feed temperature increases. The process in which the product of transesterification of soybean oil with supercritical methanol is cooled to an appropriate temperature (about 240°C) first and then flashed was put forward. The effect of cooling temperature, feed pressure and flash pressure on methanol concentration and recovery percentage was investigated. According to this study, when the feed pressure range is 15–30 MPa, the flash pressure equals 0.4 MPa, and cooling temperature range is 240°C–250°C, the recovery percentage of methanol is not less than 85%, and the concentration of the vapor in mass fraction of methanol is approximately 99%. Thus, the vapor leaving the flash tank can be directly circulated to the transesterification reactor.

关键词： supercritical methanol     biodiesel     recovery     flash distillation    

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Benzene degradation in waste gas by photolysis and photolysis-ozonation: experiments and modeling

Fariba Mahmoudkhani, Maryam Rezaei, Vahid Asili, Mahsasadat Atyabi, Elena Vaisman, Cooper H. Langford, Alex De Visscher

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0876-4

摘要： A photochemical model of benzene degradation compares well with experimental data obtained in the Lab. 62 reactions were needed to fully describe benzene degradation. A feasibility study shows that the photolysis of benzene is a cost-effective process. Experimental data and modeling results show that the degradation efficiency will increase when the combination of UV light and ozone is used. The degradation of benzene, a carcinogenic air pollutant, was studied in a gas-phase photochemical reactor with an amalgam lamp emitting ultraviolet light at 185 and 254 nm. Efficient benzene degradation (>70%) was possible for benzene mass flow rates of up to 1.5 mg·min . Adding ozone allowed benzene mass flow rates of up to 5 mg·min to be treated with the same efficiency. In terms of energy consumption, ozone doubles the efficiency of the process. A comprehensive mechanistic simulation model was developed incorporating a chemical kinetics model (62 reactions involving 47 chemical species), a material balance model incorporating diffusion and flow, a flow velocity model, and a light field model. The model successfully predicted the efficiency of the reactor, generally within 20%, which indicates that the model is sound, and can be used for feasibility studies. The prediction of the reactor efficiency in the presence of ozone was less successful, with systematically overestimated efficiency. Condensation of reaction products in the reactor is thought to be the main cause of model inaccuracy. Both experimental data and model predictions show that there is a synergistic effect between ozonation and ultraviolet degradation.

关键词： Photolysis     Ozone     Benzene     Waste gas     Simulation     Synergism    

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Ambient photolysis frequency of NO

Qi Zou,Keding Lu,Yusheng Wu,Yudong Yang,Zhuofei Du,Min Hu

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0885-3

摘要： • Chemical actinometer (CA) was built for NO photolysis frequency, j(NO ), analysis. • CA data (10% accuracy) were compared with spectroradiometer (SR) data. • Long-term j(NO ) measurement was validated by comparison of CA and SR. • Dis-benefit of aerosol on j(NO ) due toparticulate matter (PM ) control on O . The photolysis frequency of NO , j(NO ), is an important analytical parameter in the study of tropospheric chemistry. A chemical actinometer (CA) was built to measure the ambient j(NO ) based on a high precision NO instrument with 1 min time resolution. Parallel measurements of the ambient j(NO ) by using the CA and a commercial spectroradiometer (SR) were conducted at a typical urban site (Peking University Urban Environmental Monitoring Station) in Beijing. In general, good agreement was achieved between the CA and SR data with a high linear correlation coefficient ( = 0.977) and a regression slope of 1.12. The regression offset was negligible compared to the measured signal level. The j(NO ) data were calculated using the tropospheric ultraviolet visible radiation (TUV) model, which was constrained to observe aerosol optical properties. The calculated j(NO ) was intermediate between the results obtained with CA and SR, demonstrating the consistency of all the parameters observed at this site. The good agreement between the CA and SR data, and the consistency with the TUV model results, demonstrate the good performance of the installed SR instrument. Since a drift of the SR sensitivity is expected by the manufacturer, we propose a regular check of the data acquired via SR against those obtained by CA for long-term delivery of a high quality series of j(NO ) data. Establishing such a time series will be invaluable for analyzing the long-term atmospheric oxidation capacity trends as well as O pollution for urban Beijing.

关键词： Photolysis frequency of nitrogen dioxide     Chemical actinometer     Spectroradiometer     Tropospheric ultraviolet visible radiation model    

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Comparison of sequential with intimate coupling of photolysis and biodegradation for benzotriazole

Shunan Shan, Yuting Zhang, Yining Zhang, Lanjun Hui, Wen Shi, Yongming Zhang, Bruce E. Rittmann

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0953-3

摘要： Benzotriazole (BTA) is an emerging contaminant that also is a recalcitrant compound. Sequential and intimate coupling of UV-photolysis with biodegradation were investigated for their impacts on BTA removal and mineralization in aerobic batch experiments. Special attention was given to the role of its main photolytic products, which were aminophenol (AP), formic acid (FA), maleic acid (MA), and phenazine (PHZ). Experiments with sequential coupling showed that BTA biodegradation was accelerated by photolytic pretreatment up to 9 min, but BTA biodegradation was slowed with longer photolysis. FA and MA accelerated BTA biodegradation by being labile electron-donor substrates, but AP and PHZ slowed the rate because of inhibition due to their competition for intracellular electron donor. Because more AP and PHZ accumulated with increasing photolysis time, their inhibitory effects began to dominate with longer photolysis time. Intimately coupling photolysis with biodegradation relieved the inhibition effect, because AP and PHZ were quickly biodegraded and did not accumulate, which accentuated the beneficial effect of FA and MA.

关键词： Benzotriazole     Photolysis     Biodegradation     Inhibition     Electron donor    

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Phase change effect of low melting point metal for an automatic cooling of USB flash memory

Haoshan GE, Jing LIU

《能源前沿（英文）》 2012年 第6卷 第3期   页码 207-209 doi: 10.1007/s11708-012-0204-z

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Synthesis of hydrophobic carbon nanotubes/reduced graphene oxide composite films by flash light irradiation

Kai Wang, Jinbo Pang, Liwei Li, Shengzhe Zhou, Yuhao Li, Tiezhu Zhang

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 376-382 doi: 10.1007/s11705-018-1705-z

摘要：

Carbon nanotubes/graphene composites have superior mechanical, electrical and electrochemistry properties with carbon nanotubes as a hydrophobicity boosting agent. Their extraordinary hydrophobic performance is highly suitable for electrode applications in lithium ion batteries and supercapacitors which often employ organic electrolytes. Also the hydrophobic features enable the oil enrichment for the crude oil separation from seawater. The ever reported synthesis routes towards such a composite either involve complicated multi-step reactions, e.g., chemical vapor depositions, or lead to insufficient extrusion of carbon nanotubes in the chemical reductions of graphene oxide, e.g., fully embedding between the compact graphene oxide sheets. As a consequence, the formation of standalone carbon nanotubes over graphene sheets remains of high interests. Herein we use the facile flash light irradiation method to induce the reduction of graphene oxides in the presence of carbon nanotubes. Photographs, micrographs, X-ray diffraction, infrared spectroscopy and thermogravimetric analysis all indicate that graphene oxides has been reduced. And the contact angle tests confirm the excellent hydrophobic performances of the synthesized carbon nanotube/reduced graphene oxide composite films. This one-step treatment represents a straightforward and high efficiency way for the reduction of carbon nanotubes/graphene oxides composites.

关键词： carbon nanotubes     graphene composite     flash irradiation method     reduced graphene oxide     contact angles    

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A photolysis coefficient for characterizing the response of aqueous constituents to photolysis

David R. HOKANSON,Ke LI,R. Rhodes TRUSSELL

《环境科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 428-437 doi: 10.1007/s11783-015-0780-3

摘要： UV photolysis and UV based advanced oxidation processes (AOPs) are gaining more and more attention for drinking water treatment. Quantum yield ( ) and molar absorption coefficient ( ) are the two critical parameters measuring the effectiveness of photolysis of a compound. The product of the two was proposed as a fundamental measure of a constituent’s amenability to transformation by photolysis. It was shown that this product, named the photolysis coefficient, , can be determined using standard bench tests and captures the properties that govern a constituent’s transformation when exposed to light. The development showed the photolysis coefficient to be equally useful for microbiological, inorganic and organic constituents. Values of calculated by the authors based on quantum yield and molar absorption coefficient data from the literature were summarized. Photolysis coefficients among microorganisms ranged from 8500 to more than 600000 and are far higher than for inorganic and organic compounds, which varied over a range of approximately 10 to 1000 and are much less sensitive to UV photolysis than the microorganisms.

关键词： UV photolysis     disinfection     advanced oxidation     N-nitrosodimethylamine     quantum yield     absorption coefficient    

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Estimation of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitative

Davoud BEIKNEJAD,Mohammad Javad CHAICHI

《环境科学与工程前沿（英文）》 2014年 第8卷 第5期   页码 683-692 doi: 10.1007/s11783-014-0680-y

摘要： In this paper the photolysis half-lives of the model dyes in water solutions and under ultraviolet (UV) radiation were determined by using a continuous-flow spectrophotometric method. A quantitative structure-property relationship (QSPR) study was carried out using 21 descriptors based on different chemometric tools including stepwise multiple linear regression (MLR) and partial least squares (PLS) for the prediction of the photolysis half-life ( ) of dyes. For the selection of test set compounds, a K-means clustering technique was used to classify the entire data set, so that all clusters were properly represented in both training and test sets. The QSPR results obtained with these models show that in MLR-derived model, photolysis half-lives of dyes depended strongly on energy of the highest occupied molecular orbital ( ), largest electron density of an atom in the molecule ( ) and lipophilicity (log ). While in the model derived from PLS, besides aforementioned and descriptors, the molecular surface area ( ), molecular weight ( ), electronegativity ( ), energy of the second highest occupied molecular orbital ( ) and dipole moment ( ) had dominant effects on logt values of dyes. These were applicable for all classes of studied dyes (including monoazo, disazo, oxazine, sulfonephthaleins and derivatives of fluorescein). The results were also assessed for their consistency with findings from other similar studies.

关键词： dye     photolysis half-life     quantitative structure-property relationship     continuous-flow     stepwise multiple linear regression     partial least squares    

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Predictive models on photolysis and photoinduced toxicity of persistent organic chemicals

Qing ZHANG

《环境科学与工程前沿（英文）》 2013年 第7卷 第6期   页码 803-814 doi: 10.1007/s11783-013-0547-7

摘要： Photodegradation is a major abiotic transformation pathway of toxic chemicals in the environment, which in some cases might lead to photoinduced toxicities. The data on photodegradation kinetics and photoinduced toxicities of organic chemicals are essential for their risk assessment. However, the relevant data are only available for a limited number of chemicals, due to the difficulty and high cost of experimental determination. Quantitative structure-activity relationship (QSAR) models that relate photodegradation kinetics or photoinduced toxicity of organic chemicals with their physicochemical properties or molecular structural descriptors may enable simple and fast estimation of their photochemical behaviors. This paper reviews the QSAR models on photodegradation quantum yields and rate constants for toxic organic chemicals in different media including liquid phase, gaseous phase, surfaces of plant leaves, and QSAR models on photoinduced toxicity of organic chemicals to plants, bacteria, and aquatic invertebrates. Further prospects for QSAR model development on photodegradation kinetics and photoinduced toxicity of refractory organic chemicals are proposed.

关键词： quantitative structure-activity relationship (QSAR) models     photodegradation     persistent organic pollutants     environmental media     mechanisms    

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闪速熔炼——清洁高效的炼铜工艺

周松林

《中国工程科学》 2001年 第3卷 第10期   页码 86-89

摘要：

闪速熔炼是当今铜冶金中最具有竞争力的熔炼技术，被认为是标准的清洁炼铜工艺。目前，全球粗铜产量的50%是采用该技术生产的。由于闪速熔炼符合可持续发展战略，世界上大部分新建或改扩建的铜企业均选择该工艺。文章就铜闪速熔炼的特点及发展，阐述了我国铜冶金的现状，提出了我国铜冶金的主要发展方向。

关键词： 闪速熔炼     铜冶金     环保     清洁生产    

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chemical descriptors into quantitative structure-property relationship models for prediction of the photolysis

Yueping BAO, Qiuying HUANG, Wenlong WANG, Jiangjie XU, Fan JIANG, Chenghong FENG

《环境科学与工程前沿（英文）》 2011年 第5卷 第4期   页码 505-511 doi: 10.1007/s11783-011-0318-2

摘要： Quantitative structure-property relationship (QSPR) models were developed for prediction of photolysis half-life ( ) of polychlorinated biphenyls (PCBs) in water under ultraviolet (UV) radiation. Quantum chemical descriptors computed by the PM3 Hamiltonian software were used as independent variables. The cross-validated value for the optimal QSPR model is 0.966, indicating good prediction capability for lg values of PCBs in water. The QSPR results show that the largest negative atomic charge on a carbon atom ( ) and the standard heat of formation (Δ ) have a dominant effect on values of PCBs. Higher values or lower Δ values of the PCBs leads to higher lg values. In addition, the lg values of PCBs increase with the increase in the energy of the highest occupied molecular orbital values. Increasing the largest positive atomic charge on a chlorine atom and the most positive net atomic charge on a hydrogen atom in PCBs leads to the decrease of lg values.

关键词： photolysis     polychlorinated biphenyls (PCBs)     quantitative structure-property relationships (QSPRs)     quantum chemical descriptors    

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Toward better understanding vacuum ultraviolet–iodide induced photolysis via hydrogen peroxide formation

《环境科学与工程前沿（英文）》 2022年 第16卷 第5期 doi: 10.1007/s11783-021-1489-0

摘要：

• UV/VUV/I– induces substantial H2O2 and IO3– formation, but UV/I– does not.

关键词： Vacuum ultraviolet     Hydrogen peroxide     Iodate     Hydroxyl radical     Redox transition    

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Prediction of the flash points of alkanes by group bond contribution method using artificial neural networks

PAN Yong, JIANG Juncheng, WANG Zhirong

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 390-394 doi: 10.1007/s11705-007-0071-z

摘要： A group bond contribution model using artificial neural networks, which had the high ability of nonlinear of prediction, was established to predict the flash points of alkanes. This model contained not only the information of group property but also connectivity in molecules. A set of 16 group bonds were used as input parameters of neural networks to study the correlation of molecular structures with flash points of 44 alkanes. The results showed that the predicted flash points were in good agreement with the experimental data that the absolute mean absolute error was 6.9 K and the absolute mean relative error was 2.29%, which were superior to those of traditional group contribution methods. The method can be used not only to reveal the quantitative correlation between flash points and molecular structures of alkanes but also to predict the flash points of organic compounds for chemical engineering.

关键词： information     nonlinear     quantitative correlation     superior     molecular    

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冷风闪速冶金在中国的实现和发展

张文海

《中国工程科学》 2002年 第4卷 第11期   页码 19-25

摘要：

基于常温变量喷射—动力波洗涤闪速炼铜技术，介绍了“冷风闪速冶金”等6项创新技术在金隆铜业公司的实施和实现清洁生产的业绩，并就我国铜、镍闪速冶金技术提出了近期的研究方向。

关键词： 铜冶金     闪速熔炼     冷风冶炼     动力波洗涤     中国    

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标题 作者 时间 类型 操作

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

Simulation analysis of methanol flash distillation circulation process in biodiesel production with supercritical

Zhengjiao TANG, Cunwen WANG, Weiguo WANG, Jia GUO, Yuanxin WU, Jinfang CHEN, Yigang DING

期刊论文

Benzene degradation in waste gas by photolysis and photolysis-ozonation: experiments and modeling

Fariba Mahmoudkhani, Maryam Rezaei, Vahid Asili, Mahsasadat Atyabi, Elena Vaisman, Cooper H. Langford, Alex De Visscher

期刊论文

Ambient photolysis frequency of NO

Qi Zou,Keding Lu,Yusheng Wu,Yudong Yang,Zhuofei Du,Min Hu

期刊论文

Comparison of sequential with intimate coupling of photolysis and biodegradation for benzotriazole

Shunan Shan, Yuting Zhang, Yining Zhang, Lanjun Hui, Wen Shi, Yongming Zhang, Bruce E. Rittmann

期刊论文

Phase change effect of low melting point metal for an automatic cooling of USB flash memory

Haoshan GE, Jing LIU

期刊论文

Synthesis of hydrophobic carbon nanotubes/reduced graphene oxide composite films by flash light irradiation

Kai Wang, Jinbo Pang, Liwei Li, Shengzhe Zhou, Yuhao Li, Tiezhu Zhang

期刊论文

A photolysis coefficient for characterizing the response of aqueous constituents to photolysis

David R. HOKANSON,Ke LI,R. Rhodes TRUSSELL

期刊论文

Estimation of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitative

Davoud BEIKNEJAD,Mohammad Javad CHAICHI

期刊论文

Predictive models on photolysis and photoinduced toxicity of persistent organic chemicals

Qing ZHANG

期刊论文

闪速熔炼——清洁高效的炼铜工艺

周松林

期刊论文

chemical descriptors into quantitative structure-property relationship models for prediction of the photolysis

Yueping BAO, Qiuying HUANG, Wenlong WANG, Jiangjie XU, Fan JIANG, Chenghong FENG

期刊论文

Toward better understanding vacuum ultraviolet–iodide induced photolysis via hydrogen peroxide formation

期刊论文

Prediction of the flash points of alkanes by group bond contribution method using artificial neural networks

PAN Yong, JIANG Juncheng, WANG Zhirong

期刊论文

冷风闪速冶金在中国的实现和发展

张文海

期刊论文