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Heterogeneous reactions of gaseous methanesulfonic acid with calcium carbonate and kaolinite particles

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Science China Chemistry 2010年第12期53卷 2657-2662页

作者： TANG MingJin,li MengQiu & zhu {2. state key joint laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering,Peking University,Bei{12. 100871,China 1. state key {2. laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering Peking University Beijing 100871 China

Heterogeneous reactions of gaseous methanesulfonic acid (MSA) with calcium carbonate (CaCO3) and kaolinite particles at room temperature were investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Methanesulfonate (MS-) was identified as the product in the condensed phase,in accordance with the product of the reaction of gaseous MSA with NaCl and sea salt *** the concentration of gaseous MSA was 1.34 × 10-13 molecules cm-3,the uptake coefficient was (1.2. ± 0.06) × 10-8 (1) for the reaction of gaseous MSA with CaCO3 and (4.10 ± 0.65) × 10 10 (1) for the reaction with *** uptake coefficients were significantly smaller than those of the reactions of gaseous MSA with NaCl and sea salt particles.

关键词： gaseous MSA heterogeneous reaction calcium carbonate kaolinite

Heterogeneous reactions of SO_2.on ZnO particle surfaces

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Science China Chemistry 2011年第1期54卷 161-166页

作者： li Jia,shang jing & {2. tong state key joint laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering,Peking University,Beijing 100871,China 1. state key {2. laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering Peking University Beijing 100871 China

Heterogeneous reactions of SO2.on ZnO particle surfaces were studied using in situ diffuse reflectance infrared Fourier transform spectroscopy （DRIFTS）. The influences of relative humidity （RH） and UV radiation （2. 365 nm） were investigated. In the absence of UV radiation, sulfite was the prominent product on the particle surfaces, and a negative relationship between RH and sulfite production was observed. In the presence of UV radiation, infrared （IR） absorption of sulfite and sulfate was evident in the spectra. With increasing RH or UV intensity, sulfite was gradually transformed into sulfate. UV intensity and RH exhibited a synergistic effect on the heterogeneous oxidation of SO2.on ZnO. On dry particles and with no UV radiation, the reaction order of SO2.on ZnO particles was 1.6. The initial uptake coefficient for the formation of sulfite, using the Brunauer-Emmett-Teller （BET） area as the reactive surface area of SO2. was 4.87 × 10^-6. At 40% RH and with UV radiation, the reaction order was 0.91, and the initial uptake coefficient was 2.2. ×10^-5.

关键词： SO2 ZnO DRIFTS heterogeneous oxidation UV radiation

The roles of heterogeneous chemical processes in the formation of an air pollution complex and gray haze

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Science China Chemistry 2011年第1期54卷 145-153页

作者： zhu tong,{2. & ZHAO DeFeng state key joint laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering,Peking University,Bei{12. 100871,China 1. state key {2. laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering Peking University Beijing 100871 China

Urban and regional air pollutions are characterized by high concentrations of secondary pollutants such as photo-oxidants （mainly ozone） and fine particulate matter, which are formed through chemical reactions of the primary pollutants emitted from various sources. The accumulation of these pollutants under stagnant meteorological conditions results in the formation of gray haze, reducing visibility and causing major impacts on human health and climate. In an air pollution complex, the co- existence of high concentrations of primary and secondary gaseous and particulate pollutants provides a large amount of reac- tants for heterogeneous reactions on the surface of fine particles; these reactions change the oxidizing capacity of the atmos- phere, as well as chemical compositions along with the physicochemical and optical properties of particulate matter, thereby accelerating formation of the air pollution complex and gray haze. Using in situ technologies, such as diffuse reflectance infra- red Fourier-transform spectroscopy and single-particle Raman spectroscopy, we systematically investigated the reaction kinet- ics and mechanisms of gaseous pollutants （i.e., NO2. SO2. 03, and formaldehyde） on the surfaces of the major components of atmospheric particles such as CaCO3, kaolinite, montmorillonite, NaC1, sea salt, A12.3, and Tit2. We found that the main re- action products were sulfate, nitrate, or formate, which can change the hygroscopicity and light extinction parameters of those particles significantly. By analyzing the reaction kinetics of these heterogeneous reactions, we identified synergetic mechanisms of the three ternary reaction systems, ,i.e., NOE-particles-H2., SO2.particles-O3, and organics/SO2.particles-UV illumination. These synergetic mechanisms can provide experimental and theoretical bases for understanding the feedback mechanisms and nonlinear processes in the formation of an air pollution complex and gray haze.

关键词： fine particles secondary pollutants oxidizing capacity ternary reaction nonlinear processes

Photocatalytic degradation of rhodamine B by dye-sensitized TiO_2.under visible-light irradiation

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Science China Chemistry 2011年第1期54卷 167-172页

作者： shang jing,ZHAO FengWei,zhu {2. & li Jia state key joint laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering,Peking University,Beijing 100871,China 1. state key {2. laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering Peking University Beijing 100871 China

Perylene tetracarboxylic diimide (PTCDI),widely used in organic photovoltaic devices,is an n-type semiconductor with strong absorption in the visible-light *** has been almost no study of the PTCDI-sensitized TiO2.composite used to photocatalytically degrade *** this study,PTCDIand copper phthalocyanine tetrasulfonic acid (CuPcTs)-sensitized TiO2.composites were prepared using a hydrothermal *** morphologies and structures of the two composites were characterized by X-ray diffraction,transmission electron microscopy,ultraviolet-visible spectroscopy,and fluorescence *** visible-light photocatalytic activities of the composites were evaluated using the degradation of rhodamine B as a model *** showed that dye-sensitized TiO2.samples had a wider absorption spectrum range and higher visiblelight photocatalytic activity compared to TiO2.*** double dye-sensitized (or co-sensitized) TiO2.composite with efficient electron collection exhibited higher photocatalytic activity than did the single dye-sensitized TiO2.*** electron transfer processes of single and double dye-sensitized TiO2.composites were illustrated according to band theory.

关键词： copper phthalocyanine tetrasulfonic acid dye sensitization perylene tetracarboxylic diimide rhodamine B visible-lightphotocatalysis

Heterogeneous reaction of formaldehyde on the surface of TiO_2.particles

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Science China Chemistry 2010年第12期53卷 2644-2651页

作者： XU BingYe 1,2.zhu tong 1,TANG XiaoYan 1 & {2. 1 1 state key joint laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering,Peking University,Bei{12. 100871,China 2.Zhejiang Province environmental Monitoring Center,Hangzhou 310012.China 1. state key {2. laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering Peking University Beijing 100871 China2. Zhejiang Province Environmental Monitoring Center Hangzhou 310012 China

The heterogeneous reaction of formaldehyde (HCHO) on the surface of titanium dioxide (TiO2. was investigated in situ using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) combined with ion chromatography (IC),X-ray diffraction (XRD),and transmission electron microscopy (TEM).Formate,dioxymethylene,methoxy,and polyoxymethylene were observed in the infrared spectra of TiO2.particles during the *** the surface of TiO2.the adsorbed HCHO was first oxidized to dioxymethylene and further oxidized to *** effects of temperature and ultraviolet radiation (UV) on the reaction products and reactive uptake coefficients were studied,and the results indicate that the reaction rate can be accelerated at increasing temperatures as well as under *** heterogeneous reaction mechanisms of HCHO on the surface of TiO2.in the dark and under UV irradiation are *** measurements show that formate formation on TiO2.is second order in HCHO concentration and the initial reactive uptake coefficients at room temperature calculated with the Brunauer-EmmettTeller specific surface area are (0.5-5) × 10-8 ([HCHO]:1 × 1013-2.× 10 14 molecules/cm3).A linear function relationship exists between the uptake coefficient and the *** apparent activation energy of the reaction was also determined.

关键词： DRIFTS formaldehyde heterogeneous reaction reactive uptake coefficient TiO2

Hydroxyl radicals induced by quartz particles in lung alveolar macrophages: the role of surface iron

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Progress in Natural Science:Materials International 2006年第10期16卷 1038-1044页

作者： li Yi, zhu {2., GUO Xinbiao and shang Yu ( state key joint laboratory for environmental simulation & pollution control, Peking University, Bei{12. 100871, China Occupational & environmental Health Sciences, School of Public Health, Peking University Health Science Center, Bei{12. 100083, China) [a]state key {2. laboratory for environmental simulation & pollution control Peking University Beijing China [b]Occupational & environmental Health Sciences School of Public Health Peking University Health Science Center Beijing China

Previous studies have shown that hydroxyl radical generation is a key step in the mechanism of pathogenic process caused by airborne particles to the lung. However, there is no direct evidence for dose-response relationship between airborne particles and hydroxyl radical generation. In this study, hydroxyl radicals generated in lung alveolar macrophages exposed to quartz particles were measured using a highly sensitive capillary electrophoresis-fluorescence detection method. The results demonstrated that quartz particles induced the generation of hydroxyl radical in a dose-dependent manner, and the amount of the hydroxyl radicals was 10-10 mol/10 cells. The viability of alveolar macrophages exposed to quartz particles decreased with the increase of quartz concentration, showing a clear dose-response relationship. Hydroxyl radical scavenger mannitol could increase the viability of quartz-treated cells, suggesting that hydroxyl radical contributed directly to cell death. In this study this contribution accounted for about 5%-2.% of cell death. The hydroxyl radical generating potential was found to be related to surface iron content of the quartz particles.

关键词： inhalable quartz hydroxyl radical capillary electrophoresis dose-response relationship iron.

Development of a Method to Determine the environmental Burden of Diseases and an Application to Identify Factors Driving Changes in the Number of PM_(2.5)-Related Deaths in China between 2.00 and 2.10

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Environment & Health 2024年第9期2卷 642-650页

作者： Ning Kang Pengfei li Tao Xue tong {2. Institute of Reproductive and Child Health National Health Commission Key Laboratory of Reproductive Health/Department of Epidemiology and BiostatisticsMinistry of Education Key Laboratory of Epidemiology of Major Diseases(PKU)School of Public HealthPeking University Health Science CenterBeijing 100191China Institute of Medical Technology Peking University Health Science CenterBeijing 100191China Advanced Institute of Information Technology Peking UniversityHangzhou 311215China state environmental Protection {2. laboratory of Atmospheric Exposure and Health Risk Management and Center for Environment and HealthPeking UniversityBeijing 100871China state environmental Protection {2. laboratory of Atmospheric Exposure and Health Risk Management and Center for Environment and Health and State Key Joint Laboratory of Environment Simulation and Pollution ControlCollege of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

The attributable burden is codetermined by the exposure level and nontarget ***,the conventional method of health impact assessment based on preestablished exposure−response functions includes only a few well-known characteristics and thus is insufficient to capture the comprehensive *** aimed to develop a method to fuse health impact assessment with epidemiological analysis and to identify factors driving baseline *** method was applied to identify the factors underlying the change in the number of fine particulate matter(PM_(2.5))related deaths in China between 2.00 and *** the study period,the number of PM_(2.5)-related deaths across China's Mainland increased by 0.62.95%CI:0.57,0.69)million,with 0.65(95%CI:0.47,0.91)million,0.55(95%CI:0.39,0.79)million,and 0.11(95%CI:0.06,0.18)million deaths being associated with increased PM_(2.5)exposure,population aging,and growth in population size,***,economic growth,urbanization,improvement of welfare services,and improvement of hospital services resulted in 0.2.(95%CI:0.15,0.40)million,0.16(95%CI:0.10,0.2.)million,0.16(95%CI:0.09,0.2.)million,and 0.09(95%CI:0.05,0.15)million fewer deaths,*** indicated that increased exposure was the major driver of the change in the number of PM_(2.5)-related deaths,and economic growth was the main driver of increased resilience to air {12..

关键词： health burden decomposition analysis air pollution fine particulate matter premature deaths

Heterogeneous reactions on the surface of fine particles in the atmosphere

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Chinese Science Bulletin 2003年第21期48卷 2267-2276页

作者： DING Jie & zhu tong {2. key joint laboratory of environmental simulation and pollution control, College of environmental Sciences, Peking University, Beijing 100871, China Correspondence should be addressed to zhu tong (e-mail:tzhu@ ***) state key {2. laboratory of environmental simulation and pollution control College of Environmental Sciences Peking University China

Fine particles play an important role in the atmosphere. Research on heterogeneous reactions on the surface of fine particles is one of the frontier areas of atmospheric science. In this paper, physical and chemical characteristics of fine particles in the atmosphere and the interactions between trace gases and fine particles are described, methods used in heterogeneous reactions research are discussed in detail, progress in the study of heterogeneous reactions on the surface of fine particles in the atmosphere is summarized, existing important questions are pointed out and future research directions are suggested.

关键词：细微颗粒大气科学多相反应空气动力学

Raman micro-spectrometry as a technique for investigating heterogeneous reactions on individual atmospheric particles

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Science China Chemistry 2011年第1期54卷 154-160页

作者： ZHAO DeFeng,zhu tong,CHEN Qi,{2.U YingJun & ZHANG ZeFeng state key joint laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering,Peking University,Bei{12. 100871,China 1. state key {2. laboratory of environmental simulation and pollution control College of environmental Sciences and Engineering Peking University Beijing 100871 China

Investigating the heterogeneous reaction on individual atmospheric particles is important because it approximates actual atmospheric conditions and can aid in reducing artifacts in elucidating real mechanisms and processes,and determining real kinetic parameters of the atmosphere *** study developed a Raman microspectrometry method to investigate heterogeneous reactions on individual *** method was applied to the reaction of NO2.with individual CaCO3 *** was demonstrated that Raman microspectrometry can obtain information on both chemical composition and microscopic morphology at the same time,as well as information on chemical characteristics,such as the phase,which is useful for studying reaction *** spectra of individual particles deposited on a substrate showed no interference by morphological resonance,which is helpful for obtaining high-quality ***,Raman microspectrometry was compared with other methods for investigating heterogeneous reactions on individual particles and was found to have several advantageous characteristics.

关键词： Raman microspectrometry individual atmospheric particle heterogeneous reaction