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Atmospheric heterogeneous reaction of chlorobenzene on mineral -FeO particulates: a chamber experiment

《环境科学与工程前沿(英文)》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1734-9

摘要:

● Photochemical conversion of chlorobenzene (CB) on α-Fe2O3 was evaluated.

关键词: Photochemical conversion     Chlorobenzene     α-Fe2O3     PCDD/Fs     Mineral particulate    

Secondary aerosol formation in winter haze over the Beijing-Tianjin-Hebei Region, China

Dongjie Shang, Jianfei Peng, Song Guo, Zhijun Wu, Min Hu

《环境科学与工程前沿(英文)》 2021年 第15卷 第2期 doi: 10.1007/s11783-020-1326-x

摘要: Abstract • Characteristics and interannual variation of aerosol pollution are illustrated. • Mechanisms of secondary aerosol formation in winter haze of North China are reviewed. • Directions in future studies of secondary aerosol formation are provided. Severe haze pollution occurs frequently in the winter over the Beijing-Tianjin-Hebei (BTH) region (China), exerting profound impacts on air quality, visibility, and human health. The Chinese Government has taken strict mitigation actions since 2013 and has achieved a significant reduction in the annual mean PM2.5 concentration over this region. However, the level of secondary aerosols during heavy haze episodes showed little decrease during this period. During heavy haze episodes, the concentrations of secondary aerosol components, including sulfate, nitrate and secondary organics, in aerosol particles increase sharply, acting as the main contributors to aerosol pollution. To achieve effective control of particle pollution in the BTH region, the precise and complete secondary aerosol formation mechanisms have been investigated, and advances have been made about the mechanisms of gas phase reaction, nucleation and heterogeneous reactions in forming secondary aerosols. This paper reviews the research progress in aerosol chemistry during haze pollution episodes in the BTH region, lays out the challenges in haze formation studies, and provides implications and directions for future research.

关键词: Secondary aerosol formation     Regional haze     Photochemical reaction     Aqueous reaction     Chemical mechanism    

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 372-381 doi: 10.1007/s11705-010-0005-z

摘要: Thrombus formation and blood coagulation are serious problems associated with blood contacting products, such as catheters, vascular grafts, artificial hearts, and heart valves. Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper. Three approaches to modify biomaterial surfaces for improving the hemocompatibility, i.e., bioinert surfaces, immobilization of anticoagulative substances and biomimetic surfaces, are introduced. The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp (RGD) sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces. The RGD sequence can enhance adhesion and growth of endothelial cells (ECs) on material surfaces and increase the retention of ECs under flow shear stress conditions. This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.

关键词: biomimetic amphiphilic     amphiphilic phosphorylcholine     endothelial     functional     biomaterial    

Identification of sources, characteristics and photochemical transformations of dissolved organic matter

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1340-z

摘要:

• The source of DOM in surface water and sediment is inconsistent.

关键词: Dissolved organic matter     Parallel factor analysis     Excitation-emission matrices     Photodegradation    

Photochemical indicators of ozone sensitivity: application in the Pearl River Delta, China

Lyumeng Ye,Xuemei Wang,Shaofeng Fan,Weihua Chen,Ming Chang,Shengzhen Zhou,Zhiyong Wu,Qi Fan

《环境科学与工程前沿(英文)》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0887-1

摘要: The distribution of NO - and VOC-sensitive regimes in the PRD are identified. The effectiveness of six popular chemical indicators for discriminating O sensitivity regimes is evaluated. Threshold levels for HCHO/NO , H O /HNO , O /NO , O /NO , O /HNO were derived and verified. The indicators H O /HNO and H O /NO performed best and maintained relatively stable threshold levels. Surface O production has a highly nonlinear relationship with its precursors. The spatial and temporal heterogeneity of O -NO -VOC-sensitivity regimes complicates the control- decision making. In this paper, the indicator method was used to establish the relationship between O sensitivity and assessment indicators. Six popular ratios indicating ozone-precursor sensitivity, HCHO/NO , H O /HNO , O /NO , O /NO , O /HNO , and H O /NO , were evaluated based on the distribution of NO - and VOC-sensitive regimes. WRF-Chem was used to study a serious ozone episode in fall over the Pearl River Delta (PRD). It was found that the south-west of the PRD is characterized by a VOC-sensitive regime, while its north-east is NO -sensitive, with a sharp transition area between the two regimes. All indicators produced good representations of the elevated ozone hours in the episode on 6 November 2009, with H O /HNO being the best indicator. The threshold sensitivity levels for HCHO/NO , H O /HNO , O /NO , O /NO , O /HNO , and H O /NO were estimated to be 0.41, 0.55, 10.2, 14.0, 19.1, and 0.38, respectively. Threshold intervals for the indicators H O /HNO , O /NO , O /NO , O /HNO , and H O /NO were able to identify more than 95% of VOC- and NO -sensitive grids. The ozone episode on 16 November 16 2008 was used to independently verify the results, and it was found that only H O /HNO and H O /NO were able to differentiate the ozone sensitivity regime well. Hence, these two ratios are suggested as the most appropriate indicators for identifying fall ozone sensitivity in the PRD. Since the species used for indicators have seasonal variation, the utility of those indicators for other seasons should be investigated in the future work.

关键词: Ozone     Pearl River Delta (PRD)     Sensitivity regime     Photochemical indicator     Threshold levels    

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1700-1712 doi: 10.1007/s11705-022-2207-6

摘要: The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha. Herein, for a better catalyst design and operation parameters optimization, the reaction pathways and equilibrium yields for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins were analyzed thermodynamically. The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways, respectively. However, the formation of light paraffin severely limits the maximum selectivity toward light olefins. The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins. The results are thus useful as a direction for future catalyst improvements, facilitating superior reaction pathways to enhance light olefins. In addition, the equilibrium yield of light olefins increased with increasing the chain length, and the introduction of cyclo-paraffin inhibits the formation of light olefins. High temperatures and low pressures favor the formation of ethylene, and moderate temperatures and low pressures favor the formation of propylene. n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90% and 55.77%, respectively. This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词: naphtha     catalytic pyrolysis     reaction pathway     equilibrium yield    

催化裂化过程反应化学的进展

许友好,汪燮卿

《中国工程科学》 2007年 第9卷 第8期   页码 6-14

摘要:

面对催化裂化工艺所遇到的挑战,提出了催化裂化过程反应化学的多维反应结构模式。多维反应结构模式的建立是基于对烃类在酸性催化剂上反应化学认识而进行的知识创新,但多维反应结构不同于烃类在酸性催化剂上反应化学。具有多维反应结构的催化裂化工艺更具有多样性和灵活性,基于此已成功地开发了多产异构烷烃的催化裂化工艺和生产清洁汽油和多产丙烯的催化裂化工艺。

关键词: 催化裂化     反应化学     催化剂     多维反应结构     两个反应区    

Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

《环境科学与工程前沿(英文)》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0836-z

摘要: We studied the heterogeneous reaction mechanism of gaseous HNO with solid NaCl. HCl is released from heterogeneous reactions between gaseous HNO and solid NaCl. Water molecules induce surface reconstruction of NaCl to facilitate the reaction. Sea salt particles containing NaCl are among the most abundant particulate masses in coastal atmosphere. Reactions involving sea salt particles potentially generate Cl radicals, which are released into coastal atmosphere. Cl radicals play an important role in the nitrogen and O cycles, sulfur chemistry and particle formation in the troposphere of the polluted coastal regions. This paper aimed at the heterogeneous reaction between gaseous HNO and solid NaCl. The mechanism was investigated by density functional theory (DFT). The results imply that water molecules induce the surface reconstruction, which is essential for the heterogeneous reaction. The surface reconstruction on the defective (710) surface has a barrier of 10.24 kcal·mol and is endothermic by 9.69 kcal·mol , whereas the reconstruction on the clean (100) surface has a barrier of 18.46 kcal·mol and is endothermic by 12.96 kcal·mol . The surface reconstruction involved in water-adsorbed (710) surface is more energetically favorable. In comparison, water molecules adsorbed on NaCl (100) surface likely undergo water diffusion or desorption. Further, it reveals that the coordination number of the Cl is reduced after the surface reconstruction, which assists Cl to accept the proton from HNO . HCl is released from heterogeneous reactions between gaseous HNO and solid NaCl and can react with OH free radicals to produce atomic Cl radicals. The results will offer further insights into the impact of gaseous HNO on the air quality of the coastal areas.

关键词: Seasalt particles     NaCl     HNO3     Heterogeneous reaction     Reaction mechanism     Density functional theory    

Dual-reaction-center catalytic process continues Fenton’s story

Chao Lu, Kanglan Deng, Chun Hu, Lai Lyu

《环境科学与工程前沿(英文)》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1261-x

摘要: Abstract • Dual-reaction-center (DRC) system breaks through bottleneck of Fenton reaction. • Utilization of intrinsic electrons of pollutants is realized in DRC system. • DRC catalytic process well continues Fenton’s story. Triggered by global water quality safety issues, the research on wastewater treatment and water purification technology has been greatly developed in recent years. The Fenton technology is particularly powerful due to the rapid attack on pollutants by the generated hydroxyl radicals (•OH). However, both heterogeneous and homogeneous Fenton/Fenton-like technologies follow the classical reaction mechanism, which depends on the oxidation and reduction of the transition metal ions at single sites. So even after a century of development, this reaction still suffers from its inherent bottlenecks in practical application. In recent years, our group has been focusing on studying a novel heterogeneous Fenton catalytic process, and we developed the dual-reaction-center (DRC) system for the first time. In the DRC system, H2O2 and O2 can be efficiently reduced to reactive oxygen species (ROS) in electron-rich centers, while pollutants are captured and oxidized by the electron-deficient centers. The obtained electrons from pollutants are diverted to the electron-rich centers through bonding bridges. This process breaks through the classic Fenton mechanism, and improves the performance and efficiency of pollutant removal in a wide pH range. Here, we provide a brief overview of Fenton’s story and focus on combing the discovery and development of the DRC technology and mechanism in recent years. The construction of the DRC and its performance in the pollutant degradation and interfacial reaction process are described in detail. We look forward to bringing a new perspective to continue Fenton’s story through research and development of DRC technology.

关键词: Dual reaction centers     Fenton     Pollutant utilization     Electron transfer    

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1487-1499 doi: 10.1007/s11705-021-2085-3

摘要: Developing cost-effective electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is vital in energy conversion and storage applications. Herein, we report a simple method for the synthesis of graphene-reinforced CoS/C nanocomposites and the evaluation of their electrocatalytic performance for typical electrocatalytic reactions. Nanocomposites of CoS embedded in N, S co-doped porous carbon and graphene (CoS@C/Graphene) were generated via simultaneous sulfurization and carbonization of one-pot synthesized graphite oxide-ZIF-67 precursors. The obtained CoS@C/Graphene nanocomposites were characterized by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis-mass spectroscopy, scanning electronic microscopy, transmission electronic microscopy, X-ray photoelectron spectroscopy and gas sorption. It is found that CoS nanoparticles homogenously dispersed in the in situ formed N, S co-doped porous carbon/graphene matrix. The CoS@C/10Graphene composite not only shows excellent electrocatalytic activity toward ORR with high onset potential of 0.89 V, four-electron pathway and superior durability of maintaining 98% of current after continuously running for around 5 h, but also exhibits good performance for OER and HER, due to the improved electrical conductivity, increased catalytic active sites and connectivity between the electrocatalytic active CoS and the carbon matrix. This work offers a new approach for the development of novel multifunctional nanocomposites for the next generation of energy conversion and storage applications.

关键词: MOF derivative     graphene     electrocatalyst     oxygen reduction reaction     oxygen evolution reaction     hydrogen evolution reaction    

Decomposition of aqueous chlorinated contaminants by UV irradiation with H

Eunsung KAN,Chang-Il KOH,Kyunghyuk LEE,Joonwun KANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第3期   页码 429-435 doi: 10.1007/s11783-014-0677-6

摘要: In the present study, the decomposition rates of carbon tetrachloride (CCl ) and 2,4-dichlorophenol (2,4-DCP) in water by the ultraviolet (UV) light irradiation alone and H O /UV were experimentally investigated. The detailed experimental studies have been conducted for examining treatment capacities of the two different ultraviolet light sources (low and medium pressure Hg arc) in H O /UV processes. The low or medium UV lamp alone resulted in a 60%–90% decomposition of 2,4-DCP while a slight addition of H O resulted in a drastic enhancement of the 2,4-DCP decomposition rate. The decomposition rate of 2,4-DCP with the medium pressure UV lamp alone was about 3–6 times greater than the low pressure UV lamp alone. In the direct photolysis of aqueous CCl , the medium pressure UV lamp had advantage over the low pressure UV lamp because the molar extinction coefficient of CCl at shorter wavelength (210–220 nm) is about 20 to 50 times higher than that at 254 nm. However, adding H O to the medium pressure UV lamp system rendered a negative oxidation rate because H O acted as a UV absorber being competitive with CCl due to negligible reaction between CCl and OH radicals. The results from the present study indicated significant influence of the photochemical properties of the target contaminants on the photochemical treatment characteristics for designing cost-effective UV-based degradation of toxic contaminants.

关键词: H2O2/ultraviolet (UV) light     advanced oxidation     UV light irradiation     chlorinated contaminants     photochemical treatment characteristics    

Impact and inhibitory mechanism of phenolic compounds on the formation of toxic Maillard reaction products

Jing TENG, Xiaoqian HU, Ningping TAO, Mingfu WANG

《农业科学与工程前沿(英文)》 2018年 第5卷 第3期   页码 321-329 doi: 10.15302/J-FASE-2017182

摘要:

As one of the dominant reactions occurring during thermal treatment of food, the Maillard reaction not only leads to the formation of aroma, browning color and taste compounds, but also contributes to the formation of some unpleasant toxic substances including acrylamide, heterocyclic amines and advanced glycation end products. Polyphenols, one of the most abundant antioxidants in the human diet, are contained in different kinds of foods. In this review, some recent studies on the impact of dietary polyphenols on the formation of acrylamide, heterocyclic amines and advanced glycation end products formed during the Maillard reaction are summarized, including the research work conducted with both chemical model systems and real food model systems; the possible inhibitory mechanisms of different polyphenols are also summarized and discussed in this review. Basically we found that some dietary polyphenols not only scavenge free radicals, but also react with reactive carbonyl species, thus lowering the formation of toxic Maillard reaction products. This review provides a useful theoretical foundation for the application of polyphenols in food safety, and suggests some directions for further study of natural products as inhibitors against the formation of toxic substances in thermally processed food.

关键词: advanced glycation end products     acrylamide     food safety     heterocyclic amine     Maillard reaction     polyphenols    

An overview and recent advances in electrocatalysts for direct seawater splitting

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1408-1426 doi: 10.1007/s11705-021-2102-6

摘要: In comparison to pure water, seawater is widely accepted as an unlimited resource. The direct seawater splitting is economical and eco-friendly, but the key challenges in seawater, especially the chlorine-related competing reactions at the anode, seriously hamper its practical application. The development of earth-abundant electrocatalysts toward direct seawater splitting has emerged as a promising strategy. Highly efficient electrocatalysts with improved selectivity and stability are of significance in preventing the interference of side reactions and resisting various impurities. This review first discusses the macroscopic understanding of direct seawater electrolysis and then focuses on the strategies for rational design of electrocatalysts toward direct seawater splitting. The perspectives of improved electrocatalysts to solve emerging challenges and further development of direct seawater splitting are also provided.

关键词: seawater splitting     electrocatalysts     oxygen evolution reaction     hydrogen evolution reaction     chlorine chemistry    

Behavior of aqueous stable colloidal nano-C

Jing HUO,Ye YU,Ling GE,Bo ZHANG,Yiliang HE

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 197-205 doi: 10.1007/s11783-014-0624-6

摘要: C , as one of carbon nanomaterials widely used in various fields, could be released into the water environment thus exerting some potential health risks to human beings. This work examined the behavior of aqueous stable colloidal nano-C (nC ) aggregates under different environmental conditions including Polyethylene glycol octylphenol ether (TX100) micelles concentration, pH, and reaction time when exposed to TX100 micelles. Results show that the nC aggregates became more dispersive and restored the capability of generating the singlet oxygen when exposed to TX100 micelles. With the increase of TX100 concentration, smaller average size of nC aggregates was observed in dynamic light scattering (DLS) analysis, the fluorescence intensity of TX100 was more quenched by nC aggregates, and the kinetic rate constant of generating the singlet oxygen for nC aggregates was improved. The mean size of nC aggregates in the presence of TX100 had no obvious variations when the pH ranged from 4 to 8. The longer reaction time between nC aggregates and TX100 led to a higher kinetic rate constant of generating the singlet oxygen. Collective data suggest that variations in physicochemical properties of nC aggregates are strongly dependent on the surrounding media under different environmental conditions and directly govern nC ’s transport behavior and potential toxicity.

关键词: nano-C60 (nC60) aggregates     photochemical reactivity     artificial biological membrane    

Trends of chemical speciation profiles of anthropogenic volatile organic compounds emissions in China, 2005–2020

Wei WEI, Shuxiao WANG, Jiming HAO, Shuiyuan CHENG

《环境科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 27-41 doi: 10.1007/s11783-012-0461-4

摘要: This study estimates the detailed chemical profiles of China’s anthropogenic volatile organic compounds (VOCs) emissions for the period of 2005–2020. The chemical profiles of VOCs for seven activity sectors are calculated, based on which the Photochemical Ozone Creation Potential (POCP) of VOCs for these sectors is evaluated. At the national level, the VOCs species emitted in 2005 include alkanes, alkenes and alkynes, aromatic compounds, alcohols, ketones, aldehydes, esters, ethers and halocarbons, accounting for 26.4 wt.%, 29.2 wt.%, 21.3 wt.%, 4.7 wt.%, 5.4 wt.%, 1.7 wt.%, 2.1 wt.%, 0.7 wt.% and 2.2 wt.% of total emissions, respectively. And during 2005-2020, their mass proportions would respectively grow or decrease by -6.9%, -32.7%, 7.3%, 65.3%, 34.7%, -48.6%, 108.5%, 100.5%, and 55.4%. This change would bring about a 13% reduction of POCP for national VOCs emissions in the future. Thus, although the national VOCs emissions are expected to increase by 33% over the whole period, its ozone formation potential is estimated to rise only by 14%. Large discrepancies are found in VOCs speciation emissions among provinces. Compared to western provinces, the eastern provinces with a more developed economy would emit unsaturated hydrocarbons and benzene with lower mix ratios, and aromatic compounds except benzene, oxidized hydrocarbons and halocarbons with higher mix ratios. Such differences lead to lower POCP of VOCs emitted in eastern provinces, and higher POCP of VOCs emitted in western provinces. However, due to the large VOCs emissions from Chinese eastern region, the ozone formation potential of VOCs emission in eastern provinces would be much higher than those in western provinces by about 156%–235%.

关键词: volatile organic compounds (VOCs)     chemical speciation     ozone formation     Photochemical Ozone Creation Potential (POCP)     China    

标题 作者 时间 类型 操作

Atmospheric heterogeneous reaction of chlorobenzene on mineral -FeO particulates: a chamber experiment

期刊论文

Secondary aerosol formation in winter haze over the Beijing-Tianjin-Hebei Region, China

Dongjie Shang, Jianfei Peng, Song Guo, Zhijun Wu, Min Hu

期刊论文

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

期刊论文

Identification of sources, characteristics and photochemical transformations of dissolved organic matter

期刊论文

Photochemical indicators of ozone sensitivity: application in the Pearl River Delta, China

Lyumeng Ye,Xuemei Wang,Shaofeng Fan,Weihua Chen,Ming Chang,Shengzhen Zhou,Zhiyong Wu,Qi Fan

期刊论文

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

期刊论文

催化裂化过程反应化学的进展

许友好,汪燮卿

期刊论文

Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

期刊论文

Dual-reaction-center catalytic process continues Fenton’s story

Chao Lu, Kanglan Deng, Chun Hu, Lai Lyu

期刊论文

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

期刊论文

Decomposition of aqueous chlorinated contaminants by UV irradiation with H

Eunsung KAN,Chang-Il KOH,Kyunghyuk LEE,Joonwun KANG

期刊论文

Impact and inhibitory mechanism of phenolic compounds on the formation of toxic Maillard reaction products

Jing TENG, Xiaoqian HU, Ningping TAO, Mingfu WANG

期刊论文

An overview and recent advances in electrocatalysts for direct seawater splitting

期刊论文

Behavior of aqueous stable colloidal nano-C

Jing HUO,Ye YU,Ling GE,Bo ZHANG,Yiliang HE

期刊论文

Trends of chemical speciation profiles of anthropogenic volatile organic compounds emissions in China, 2005–2020

Wei WEI, Shuxiao WANG, Jiming HAO, Shuiyuan CHENG

期刊论文