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A monitoring-modeling approach to SO_4^(2-) and NO_3^- secondary conversion ratio estimation during haze periods in Beijing, China

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Journal of Environmental Sciences 2019年第4期31卷 293-302页

作者： Xiaoqi Wang Wei Wei shuiyuan cheng Chong Zhang Wenjiao Duan Key Laboratory of Beijing on Regional Air Pollution Control Beijing University of Technology Collaborative Innovation Center of Beijing City Traffic Beijing University of Technology

SO_4^(2-) and NO_3^- are important chemical components of fine particulate matter(PM_(2.5)),especially during haze *** study selected two haze episodes in Beijing,China with similar meteorological conditions.A monitoring-modeling approach was developed to estimate the secondary conversion ratios of sulfur and nitrogen based on monitored and simulated *** showed that in Episode 1(24th–25th October,2014),the concentrations(proportions)of SO_4^(2-) and NO_3^- reached 35.1μg/m^3(14.9%) and 55.0μg/m^3(22.9%),while they reached 14.4μg/m^3(9.3%) and 59.1μg/m^3(38.1%)in Episode 2(26th–27th October,2017).A modeling system was applied to apportion Beijing's SO_4^(2-) and NO_3^- in primary and secondary SO_4^(2-)/NO_3^- emitted from local and regional ***,secondary conversion contributions considering the local and regional level were *** former primarily focused on Beijing atmospheric oxidation ability and the latter mainly considered the existence form of Beijing SO_4^(2-)/NO_3^- under the regional transport ***,secondary oxidation ratios were estimated through combining secondary conversion contribution coefficients for simulated and monitored *** regional level,sulfur oxidation ratios in polluted(clean)days during two sampling periods were0.57–0.72(0.07–0.52)and 0.74–0.80(0.08–0.61),nitrogen oxidation ratios were 0.20–0.29(0.05–0.15)and 0.34–0.38(0.02–0.29),indicating that atmospheric oxidation was enhanced when considering regional transport through 2014–*** the local level,sulfur oxidation ratios were 0.66–0.71(0.04–0.48)in haze(clean)days,while nitrogen oxidation ratios were0.16–0.29(0.02–0.16).The atmospheric oxidation ability markedly increased in PM_(2.5)pollution days,but changed only slightly between the two periods.

关键词： Haze periods SO42- and NO3- Secondary conversion Secondary oxidation ratio

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Characterization of aircraft emissions and air quality impacts of an international airport

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Journal of Environmental Sciences 2018年第10期30卷 198-207页

作者： Xiaowen Yang shuiyuan cheng Jianlei Lang Ran Xu Zhe Lv Key Laboratory of Beijing on Regional Air Pollution Control Beijing University of TechnologyBeijing 100124 China Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081 China National Meteorological Center of CMA Beijing 100081 China

Beijing Capital International Airport（ZBAA） is the world＇s second busiest airport. In this study, the emissions of air pollutants from aircraft and other sources at ZBAA in 2015 were estimated using an improved method, which considered the mixing layer height calculated based on aircraft meteorological data relay（AMDAR）, instead of using the height（915 m）recommended by ICAO. The yearly emissions of NOx, CO, VOCs, SO2, and PM2.5 at the airport were 8.76 × 10^3, 4.43 × 10^3, 5.43 × 10^2, 4.80 × 10^2, and 1.49 × 10^2 ton/year, respectively. The spatial–temporal distribution of aircraft emissions was systematically analyzed to understand the emission characteristics of aircraft. The results indicated that NOxwas mainly emitted during the take-off and climb phases, accounting for 20.5% and 55.5% of the total emissions. CO and HC were mainly emitted during the taxi phase, accounting for 91.6%and 92.2% of the total emissions. Because the mixing layer height was high in summer, the emissions of aircraft were at the highest level throughout the year. Based on the detailed emissions inventory, four seasons simulation using WRF-CMAQ model was performed over the domain surrounding the airport. The results indicated that the contribution to PM2.5 was relatively high in winter; the average impact was about 1.15 μg/m3 within a radius of1 km around the airport. Meanwhile, the near surroundings and southwest areas of the airport are the most sensitive to PM2.5.

关键词： Beijing Capital International Airport Aircraft Emission inventory Air quality

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

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Frontiers of Environmental Science & Engineering 2014年第1期8卷 27-41页

作者： Wei WEI Shuxiao WANG Jiming HAO shuiyuan cheng Department of Environmental Science and Engineering Beijing University of Technology Beijing 100124 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC) Tsinghua University Beijing 100084 China

This study estimates the detailed chemical profiles of China＇s anthropogenic volatile organic com- pounds （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 26.4wt.%, 29.2wt.%, 21.3 wt.%, 4.7 wt.%, 5.4 wt.%, 1.7 wt.%, 2.1 wt.%, 0.7 wt. % and 2.2wt.% of total emissions, respectively. And during 2005-2020, their mass proportions would respec- tively grow or decrease by - 34.7%, -48.6%, 108.5%, 6.9%, -32.7%, 7.3%, 65.3%, 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 hydrocar- bons 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 forma- tion 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) chemi-cal speciation ozone formation Photochemical OzoneCreation Potential (POCP) China

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Source apportionment of PM2.5 in Tangshan, China --Hybrid approaches for primary and secondary species apportionment

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Frontiers of Environmental Science & Engineering 2016年第5期10卷 83-96页

作者： Wei WEN shuiyuan cheng Lei LIU Gang WANG Xiaoqi WANG Key Laboratory of Beijing on Regional Air Pollution Control Beijing University of Technology Beijing 100124 China Environmental Meteorology Forecast Center of Beijing-Tianjin-Hebei Chinese Meteorological Administration Beijing 100089 China Department of Civil and Resource Engineering Dalhousie University Halifax NS B3H 4RZ Canada Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081 China

The objective of this paper is to propose a hybrid approach for the source apportionment of primary and secondary species of PM2.5 in the city of Tangshan. The receptor-based PMF （Positive Matrix Factorization） is integrated with the emission inventory （El） to form the first hybrid method for the source apportionment of the primary species. The hybrid CAMx-PSAT-CP （Comprehensive Air Quality Model with Extensions - Particulate Source *** Technology - Chemical Profile）approach is then proposed and used for the source apportionment of the secondary species. The PM2.5 sources identified for Tangshan included the soil dust, the metallurgical industry, power plants, coal- fired boilers, vehicles, cement production, and other sources. It is indicated that the PM2.5 pollution is a regional issue. Among all the identified sources, the metallurgy industry was the biggest contribution *** PM2.5, followed by coal-fired boilers, vehicles and soil dust. The other-source category plays a crucial role for PM2.5, particularly for the formation of secondary species and aerosols, and these other sources include non-specified sources such as agricultural activities, biomass combustion, residential emissions, etc. The source apportionment results could help the local authorities make sound policies and regulations to better protect the citizens from the local and regional PM2.5 pollution. The study also highlights the strength of utilizing the proposed hybrid approaches in the identification of PM2.5 sources. The techniques used in this study show considerable promise for further application to other regions as well as to identify other source categories of PM2.5.

关键词： Secondary species Emission inventory PM2.5 Source apportionment

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Deformation of freezing water droplets on a cold copper surface

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Science China(Technological Sciences) 2006年第5期49卷 590-600页

作者： WANG Jieteng LIU Zhongliang GOU Yujun ZHANG Xinhua cheng shuiyuan College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China

Freezing processes of water and peanut oil droplets on a cold surface are investigated in this paper. We observed during our experiments that the base surface of a water droplet that is in direct contact with the cold surface keeps its original shape, but the other part of the droplet shows an obvious growth along the direction normal to the base surface. One small protrusion appears on the top of the water droplet at the end of the freezing process. The experimental observations also show that no obvious shape change happens during the freezing of peanut oil droplets. It is postulated that the effects of sur- face tension and volume dilatation resulted from liquid-to-solid phase change cause the shape change and protrusions formation. Based on this postulation, a physical and mathematical model is developed. The results of the model of a water droplet’s freezing process correspond with our experimental observations. The observed phenomenon that frost-growth speed on the protrusion is higher than that on the other part of the water droplet is also analyzed.

关键词： frost, droplet, freezing, protrusion formation, surface tension.

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Characteristics of ozone and ozone precursors(VOCs and NOx) around a petroleum refinery in Beijing, China

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Journal of Environmental Sciences 2014年第2期26卷 332-342页

作者： Wei Wei shuiyuan cheng Guohao Li Gang Wang Haiyang Wang Department of Environmental Science and Engineering Beijing University of Technology State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Tsinghua University

A field measurement campaign for ozone and ozone precursors （VOCs and NOx） was conducted in summer 2011 around a petroleum refinery in the Beijing rural region. Three observation sites were arranged, one at southwest of the refinery as the background, and two at northeast of the refinery as the downwind receptors. Monitoring data revealed the presence of serious surface 03 pollution with the characteristics of high average daily mean and maximum concentrations （64.0 and 145.4 ppbV in no-rain days, respectively） and multi-peak diurnal variation. For NOx, the average hourly concentrations of NO2 and NO were in the range of 20.546.1 and 1.8-6.4 ppbV, respectively. For VOC measurement, a total of 51 compounds were detected. Normally, TVOCs at the background site was only dozens of ppbC, while TVOCs at the downwind sites reached several hundreds of ppbC. By subtracting the VOC concentrations at background, chemical profiles of VOC emission from the refinery were obtained, mainly including alkanes （60.0% ± 4.3%）, alkenes （21.1% ± 5.5%） and aromatics （18.9% ±3.9%）. Moreover, some differences in chemical profiles for the same measurement hours were observed between the downwind sites; the volume ratios of alkanes with low reactivity and those of alkenes with high reactivity respectively showed an increasing trend and a decreasing trend. Finally, based on temporal and spatial variations of VOC mixing ratios, their photochemical degradations and dispersion degradations were estimated to be 0.15-0.27 and 0.42-0.62, respectively, by the photochemical age calculation method, indicating stronger photochemical reactions around the refinery.

关键词： ozone volatile organic compounds (VOCs) photochemical degradations petroleum refinery

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A framework for investigating the air quality variation characteristics based on the monitoring data: Case study for Beijing during 2013–2016

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Journal of Environmental Sciences 2019年第7期31卷 225-237页

作者： Jixian Cui Jianlei Lang Tian Chen Shushuai Mao shuiyuan cheng Zhanshan Wang Nianliang cheng Key Laboratory of Beijing on Regional Air Pollution Control College of Environmental & Energy Engineering Beijing University of Technology Beijing Municipal Environmental Monitoring Center

In this study, an analysis framework based on the regular monitoring data was proposed for investigating the annual/inter-annual air quality variation and the contributions from different factors(i.e., seasons, pollution periods and airflow directions), through a case study in Beijing from 2013 to 2016. The results showed that the annual mean concentrations(MC) of PM_(2.5), SO_2, NO_2 and CO had decreased with annual mean ratios of 7.5%, 28.6%, 4.6%and 15.5% from 2013 to 2016, respectively. Among seasons, the MC in winter contributed the largest fractions(25.8%～46.4%) to the annual MC, and the change of MC in summer contributed most to the inter-annual MC variation(IMCV) of PM_(2.5) and NO2. For different pollution periods, gradually increase of frequency of S-1(PM_(2.5), 0～ 75 μg/m^3) made S-1 become the largest contributor(28.8%) to the MC of PM_(2.5) in 2016, it had a negative contribution(-13.1%) to the IMCV of PM_(2.5); obvious decreases of frequencies of heavily polluted and severely polluted dominated(44.7% and 39.5%) the IMCV of PM_(2.5). For different airflow directions, the MC of pollutants under the south airflow had the most significant decrease(22.5%～62.5%), and those decrease contributed most to the IMCV of PM_(2.5)(143.3%),SO2(72.0%), NO_2(55.5%) and CO(190.3%); the west airflow had negative influences to the IMCV of PM_(2.5), NO_2 and CO. The framework is helpful for further analysis and utilization of the large amounts of monitoring data; and the analysis results can provide scientific supports for the formulation or adjustment of further air pollution mitigation policy.

关键词： Monitoring data analysis Air quality variations Airflow directions Pollution periods Beijing

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Adsorption performance of CMK-3 and C-FDU-15 in NO removal at low temperature

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Journal of Environmental Sciences 2020年第1期32卷 289-298页

作者： Runping Wu Qing Ye Kai Wu shuiyuan cheng Tianfang Kang Hongxing Dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Chemistry and Chemical EngineeringCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China

CMK-3 and C-FDU-15 samples were synthesized using hard-templating and evaporationinduced self-assembly(EISA)methods,*** pore structures of CMK-3 and CFDU-15 as well as commercial activated carbon were characterized by means of X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and N2 adsorption–*** of NO was investigated by means of thermogravimetric analysis,temperature-programmed desorption of NO+O2,and in situ diffuse reflectance Fourier transform infrared *** results show that the CMK-3 and C-FDU-15 materials possessed ordered and uniform *** coadsorption capacity of NO and O2 decreased in the sequence CMK-3(88.6 mg/g)>C-FDU-15(71.7 mg/g)>AC(25.3 mg/g).There were two main adsorption species on CMK-3 and CFDU-15:nitrite and *** is converted to nitrate ***,the adsorption species were more complex on AC,with nitrite being the main ***,CMK-3 and C-FDU-15 exhibit excellent regeneration efficiency compared with *** excellent NO adsorption performance of CMK-3 and C-FDU-15 was associated with their ordered mesoporous structures and high surface *** research provides more options for NO adsorption in the future.

关键词： Ordered mesoporous carbon material CMK-3 C-FDU-15 NO adsorption species Regeneration performance

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Effect of wet flue gas desulfurization(WFGD) on fine particle(PM_(2.5)) emission from coal-fired boilers

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Journal of Environmental Sciences 2019年第3期31卷 32-42页

作者： Sen Yao shuiyuan cheng Jianbing Li Hanyu Zhang Jia Jia Xiaowei Sun Key Laboratory of Beijing on Regional Air Pollution Control Beijing University of Technology Environmental Engineering Program University of Northern British Columbia

In this study, the characteristics of fine particles before and after wet flue gas desulfurization(WFGD) in three coal-fired heating boilers in northern China were investigated by using a dilution-based emission sampling experimental system. The influences of the WFGD process on the mass and number concentrations as well as the chemical composition of fine particles were analyzed. The removal efficiency of desulfurization processes on particulate matter mass was 30.06%–56.25% for the three study units. The WFGD had a great influence on the size distributions of particle mass concentration and number concentration. A significant increase in the number and mass concentration of particles in the size range of 0.094–0.946 μm was observed. The watersoluble ion content accounted for a very large proportion of PM_(2.5) mass, and its proportion in PM_(2.5) increased from 28.39%–41.08% to 48.96%–61.21% after the WFGD process for the three units. The desulfurizing process also drastically increased the proportion of cation component(Ca^(2+) for unit A, Mg^(2+) for unit B, and Na+for unit C) and the proportion of SO_4^(2-) in PM_(2.5), and it increased the CE/AE values of PM_(2.5) from 0.82–0.98 to 0.93–1.27 for the three study units.

关键词： PM2.5 Wet flue gas desulfurization Size distribution Number concentration

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Chlorine Gas Sensors with HPS Film on Interdigitated Capacitors

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稀有金属材料与工程 2006年第A3期35卷 152-154页

作者： Wang Dao Jiang Lingyan Fan Cuiyun Yang Yang cheng shuiyuan Research Office of Chemical Sensors College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China

The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on *** of interdigital capacitance were performed at room temperature for frequencies 100 Hz,1 kHz and 10 *** is shown that there is a linear relationship between the capacitance and the concentration of chlorine *** of the measurement frequency and film thickness of silicate on the sensitivity of the sensor to C12 gas were *** organically modified N,N-diethylaminopropyl-trimethoxysilane (APMS) had a much higher sensitivity.

关键词： chlorine sensor HPS thin film interdigital capacitors

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