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Seasonal variations and sources of mass and chemical composition for PM_(10) aerosol in Hangzhou,China

Particuology 2009年第3期7卷 161-168页

作者： Junji Cao Zhenxing Shen Judith C. Chow Guowei Qi john G. watson State Key Lab of Loess and Quaternary Geology - SKLLQG. Institute of Earth Environment ChineseAcademy of Sciences Xi'an. Shaanxi 710075 China Department of Environmental Science and Engineering. xi'an Jiaotong University. Xi'an 710049. China Division of Atmospheric Sciences. Desert Research Institute. Reno. USA Hangzhou Municipal Environmental Monitoring Center Hangzhou 310007 China

Aerosol observation was conducted for four seasons from September 2001 to August 2002 at five sampling sites in Hangzhou, South China, on PM10 mass, 22 elements （Na, Mg, AI, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As. Se, Br, Cd, Ba, and Pb）, 5 major ions （F^-, Cl^ , NO3^-, SO4^2- , and NH4^＋）, and organic and elemental carbon （OC and EC）, showing that PM10 mass ranged from 46.7 to 270.8 μg/m^3, with an annual average of 119.2 μg/m^3. Na, AI, Si, S, K, Ca, and Fe were the most abundant elements in PM10, most of S being in the form of SO4^2- . SO4^2-, NO3^-, and NH4^＋ were the major ions, which contributed to about 20% of the PM10 mass. The mean seasonal concentrations for SO4^2- , averaged over all sites, were found to be 18.0, 18.5, 24,Z and 21.4 μg/m^3, for spring, summer, autumn, and winter, respectively, while the corresponding loadings for NO3^- were 7.2, 4.7, 7.1, and 11.2 μg/m^3, and for NH4^＋ were 6.0, 5.9, 8.2, and 9.3 μg/m^3, in the form mostly of NH4NO3 in spring, autumn, and winter, and mostly of （NH4）2SO4 in summer. The low NO3^-/SO4^2- ratio found indicates coal combustion as the major source throughout the year. The mean annual concentrations of OC and EC in PM10 were found to be 21.4, and 4.1 μg/m^3, respectively. Material balance calculation indicated that fugitive dust, the secondary aerosol, and carbonaceous matter were the most abundant species in PM10 for the four seasons, as is characteristic for cities in South China.

关键词： PM10 Elements lons Carbon Material balance

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Chemical Characteristics of Carbonaceous Aerosols During Dust Storms over Xi'an in China

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Advances in Atmospheric Sciences 2008年第5期25卷 847-855页

作者：李旭祥曹军骥 Judith CHOW 韩永明李顺诚 john watson Department of Environmental Science and Technology Xi'an Jiaotong University Desert Research Institute Reno NV USA State Key Lab of Loess & Quaternary Geology Institute of Earth EnvironmentChinese Academy of Sciences The Hong Kong Polytechnic University

Characterization of carbonaceous aerosols including CC （carbonate carbon）, OC （organic carbon）, and EC （elemental carbon） were investigated at Xi＇an, China, near Asian dust source regions in spring 2002. OC varied between 8.2 and 63.7μgm^- 3, while EC ranged between 2.4 and 17.2 μ m^-3 during the observation period. OC variations followed a similar pattern to EC and the correlation coefficient between OC and EC is 0.89 （n=31）. The average percentage of total carbon （TC, sum of CC, OC, and EC） in PM2.5 during dust storm （DS） events was 13.6%, which is lower than that during non-dust storm （NDS） periods （22.7%）. CC, OC, and EC accounted for 12.9%, 70.7%, and 16.4% of TC during DS events, respectively. The average ratio of OC/EC was 5.0 in DS events and 3.3 in NDS periods. The OC-EC correlation （R^2=0.76, n=6） was good in DS events, while it was stronger （R^2=0.90, n=25） in NDS periods. The percentage of watersoluble OC （WSOC） in TC accounted for 15.7%, and varied between 13.3% and 22.3% during DS events. The distribution of eight carbon fractions indicated that local emissions such as motor vehicle exhaust were the dominant contributors to carbonaceous particles. During DS events, soil dust dominated the chemical composition, contributing 69% to the PM2.5 mass, followed by organic matter （12.8%）, sulfate （4%）, EC （2.2%）, and chloride （1.6%）. Consequently, CC was mainly entrained by Asian dust. However, even in the atmosphere near Asian dust source regions, OC and EC in atmospheric dust were controlled by local emission rather titan the transport of Asian dust.

关键词： carbonate carbon organic carbon elemental carbon dust storm

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Improved estimation of PM_(2.5) brown carbon contributions to filter light attenuation

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Particuology 2021年第3期19卷 1-9页

作者： Judith C.Chow L.-W.Antony Chen Xiaoliang Wang Mark C.Green john G.watson Division of Atmospheric Sciences Desert Research InstituteRenoNVUSA State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’anChina Graduate Faculty Department of Atmospheric SciencesUniversity of NevadaReno NevadaUSA Department of Environmental and Occupational Health School of Public HealthUniversity of NevadaLas VegasNVUSA

Multiwavelength light attenuation measurements have been acquired as part of thermal/optical carbon analysis in the *** Speciation Network(CSN)and the Interagency Monitoring of PROtected Visual Environments(IMPROVE)network beginning in *** are used to estimate PM_(2.5)brown carbon(BrC)contributions to light absorption at various wavelengths,a useful method for separating biomass burning contributions from other *** of light transmitted through the filter deviates from Beers Law as the mass of light absorbing materials *** study estimates the effects of these deviations with empirical adjustment factors applied to samples for CSN from 2016 to 2017 and for IMPROVE from 2016 to *** for the filter loading effect results in an annual average increase of∼6-7%BrC contribution to light attenuation:from 3.6%to 10.7%for the urban,more heavily loaded CSN samples;and from 23.7%to 29.5%for the non-urban IMPROVE *** alternative method is examined for BrC and black carbon(BC)adjustments by calculating the AbsorptionÅngström Exponent(AAE)for BC(i.e.,AAE_(BC))based on the ratios of 635 nm/780 nm light attenuation rather than assuming AAE_(BC)of *** paired-wavelength calculations result in a median AAE_(BC)of 0.76 for CSN and 0.8 for IMPROVE,with the majority of samples(i.e.,91%of CSN and 70%of IMPROVE)showing AAE_(BC)<*** assuming negligible contributions from BrC to AAE at longer wavelengths,the amount of light attenuation at shorter wavelengths(e.g.,405 nm)where BrC is dominant can be *** paired-wavelength method applied to the filter loading adjusted data has a greater effect on urban(fresh)than on non-urban(aged)aerosols,resulting in a factor of two increase in annual averaged BrC light attenuation(from 10.7%to 21.6%)for CSN and by a factor of 1.11(from 29.5%to 32.7%)for IMPROVE *** result demonstrates the importance of particle loading and AAE correction on quantifying BrC light attenuatio

关键词： Organic carbon Brown carbon Elemental carbon Black carbon AbsorptionÅngström Exponent

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Potential emission reductions by converting agricultural residue biomass to synthetic fuels for vehicles and domestic cooking in China

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Particuology 2020年第2期18卷 40-47页

作者： Xiaoliang Wang SKent Hoekman Yang Han Judith CChow john G.watson Xiaomeng Wu Ye Wu Dennis Schuetzle Robert Schuetzle Desert Research Institute 2215 Raggio PkwyRenoNV 89512USA School of Environment Tsinghua UniversityBeijing 100084China Greyrock Energy Inc.2020 L StreetSuite 120SacramentoCA 95811USA

Vehicle exhaust and transported biomass burning emissions are important air pollution sources in many urban areas,and domestic cooking with biomass fuels causes indoor air pollution in many rural *** agricultural waste-generated synthetic fuels can reduce emissions both from vehicles and biomass *** estimate the potential benefits of synthetic diesel in Beijing,the emission factor model for the Beijing vehicle fleet was applied to estimate exhaust emissions for the 2015-2030 *** with 100%petroleum diesel,a 20%synthetic diesel blend reduced diesel fleet emissions by 24%for carbon monoxide,30%for total hydrocarbons,5.5%for nitrogen oxides,and 19%for fine particulate matter with an aerodynamic diameter of≤2.5μm(PM2.5)while using 100%synthetic diesel decreased emissions by 36%for carbon monoxide,48%for total hydrocarbons,10%for nitrogen oxides,and 34%for *** use of biomass for producing synthetic fuels rather than burning in the field also reduces air *** 60g of PM2.5 agricultural open-field burning emissions are avoided per liter of synthetic fuel *** solid crop residues with synthetic liquid fuels in household cooking would reduce PM2.5 emissions by more than 90%.

关键词： PM2.5 Air pollution Vehicle emission Biomass burning Synthetic fuel Agricultural biomass

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Dilution sampling and analysis of particulate matter in biomass-derived syngas

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Frontiers of Environmental Science & Engineering 2011年第3期5卷 320-330页

作者： Xiaoliang WANG Curtis ROBBINS S.Kent HOEKMAN Judith C.CHOW john G.watson Dennis SCHUETZLE Division of Atmospheric Sciences Desert Research Institute(DRI)RenoNV 89512USA Renewable Energy Institute International(REII)McClellanCA 95652USA

Thermochemical biomass gasification,followedby conversion of the produced syngas to fuels andelectrical power,is a promising energy *** of particulate matter(PM)and othercontaminants in the syngas is important to minimizedamage and ensure efficient operation of the engines itpowers and the fuels created from it.A dilution samplingsystem is demonstrated to quantify PM in syngas generatedfrom two gasification plants utilizing different biomassfeedstocks:a BioMax®15 Biopower System that uses rawand torrefied woodchips as feedstocks,and an integratedbiorefinery(IBR)that uses rice hulls and woodchips ***_(2.5)mass concentrations in syngas from theIBR downstream of the purification system were 12.8-13.7μg·m^(-3),which were significantly lower than themaximum level for catalyst protection(500μg·m^(-3))andwere 2-3 orders of magnitude lower than those inBioMax®15 syngas(2247-4835μg·m^(-3)).Ultrafine particlenumber concentration and PM_(2.5)chemical constituentswere also much lower in the IBR syngas than in theBioMax®*** dilution sampling system enabledreliable measurements over a wide range of concentrations:the use of high sensitivity instruments allowed measurementat very low concentrations(~1μg·m^(-3)),while theflexibility of dilution minimized sampling problems thatare commonly encountered due to high levels of tars in rawsyngas(~1 g·m^(-3)).

关键词： dilution source sampling syngas characterization biomass gasification ultrafine particles

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Real-world emission factors for Caterpillar 797B heavy haulers during mining operations

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Particuology 2016年第5期14卷 22-30页

作者： Xiaoliang Wang Judith C. Chow Steven D. Kohl Kevin E. Percy Allan H. Legge john G. watson Desert Research Institute 2215 Raggio Parkway Reno NV 895J2 USA Graduate Faculty University of Nevada Reno NV89503 USA The State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Wood Buffalo Environmental Association 330 Thickwood Boulevard Fort McMurray AB Canada 7DK 1 Y1 Biosphere Solutions 1610 1 lth Avenue N.W. Calgary AB Canada T2N IG9

Real-world fuel-based emission factors （EFs） from Caterpillar 797B diesel heavy haulers when used for oil sands mining operations were measured using an on-hoard portable emissions monitoring system. Average EFs （in g/kg fuel） for 16 separate tests on four trucks were 3150 ± 4 for CO2, 2.51 ± 1.30 for CH4, 10.28 ± 3.21 for CO, 0.61 ± 0.32 for non-methane hydrocarbons, 55.49 ± 9,75 for NOx （reported as NO2）, 0.70 ± 0.17 for PM2.s （mass of particles with aerodynamic diameter 〈2.5 μm）, and 0.34 ± 0.05 for black carbon （BC）. Ultrafine particle numbers averaged （4.7 ± 4.1 ） × 10^15 particleslkg fuel. Fuel-based EFs of NO, NO2, and particle numbers were higher during idling, whereas PM2.5 and BC EFs were higher during traveling without a load. A comparison of emissions with those reported by oil sands facilities showed large variations, both among the facilities and between the reported emissions and the real-world measurements.

关键词： Heavy hauler Emission Nonroad Portable emissions measurement system Mining Oil sands

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PM_(2.5) and PM_(10-2.5) chemical composition and source apportionment near a Hong Kong roadway

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Particuology 2015年第1期13卷 96-104页

作者： Yan Cheng Shuncheng Lee Zhaolin Gu Kinfai Ho Yunwei Zhang Yu Huang Judith C.Chow john G.watson Junji Cao Renjian Zhang Department of Environmental Science and Technology School of Human Settlements and Civil EngineeringXi'an Jiaotong University State Key Laboratory of Loess Quaternary Geology Institute of Earth and EnvironmentChinese Academy of Sciences Department of Civil and Structural Engineering Research Center for Environmental Technology and ManagementThe Hong Kong Polytechnic University School of Public Health and Primary Care The Chinese University of Hong Kong Division of Atmospheric Sciences Desert Research Institute Key Laboratory of Regional Climate-Environment Research for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of Sciences

Twenty-four-hour PM2.5 and PM10 samples were collected simultaneously at a highly trafficked road-side site in Hong Kong every sixth day from October 2004 to September 2005. The mass concentrations of PM2.5, PMlo-2.5 （defined as PM10 - PM2.5）, organic carbon （OC）, elemental carbon （EC）, water-soluble ions, and up to 25 elements were determined. Investigation of the chemical compositions and potential sources revealed distinct differences between PM2.5 and PM10-2.5. The annual average mass concentrations were 55.5 ＋ 25.5 and 25.9±15.7μg/m^3 for PM2.5 and PM10-2.5, respectively. EC, OM （OM = OC × 1.4）, and ammonium sulfate comprised over -82% of PM2.5, accounting for -29%, -27%, and -25%, respectively, of the PM2.5 mass. Low OC/EC ratios （less than 1） for PM2.5 suggested that fresh diesel-engine exhaust was a major contributor. Seven sources were resolved for PM2.5 by positive matrix factorization （PMF） model, including vehicle emissions （-29%）, secondary inorganic aerosols （-27%）, waste incinera- tor/biomass burning （-23%）, residual oil combustion （-10%）, marine aerosols （-6%）, industrial exhaust （-4%）, and resuspended road dust （-1%）. EC and OM comprised only -19% of PM10-2.5. The average OC/EC ratio of PM10-2.5 was 7.8± 14.2, suggesting that sources other than vehicular exhaust were important contributors. The sources for PM10-2.5 determined by the PMF model included -20% traffic-generated resuspension （e.g., tire dust/brake linear/petrol evaporation）, -17% locally resuspended road dust, -17% marine aerosols, -12% secondary aerosols/field burning, and -11% vehicle emissions.

关键词： PM2.5 PM10-2.5 Roadside Chemical composition Source apportionment Hong Kong

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Comparison of four scanning mobility particle sizers at the Fresno Supersite

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Particuology 2011年第3期9卷 204-209页

作者： john G. watson Judith C. Chow David A. Sodeman Douglas H. Lowenthal M.-C. Oliver Chang Kihong Park Xiaoliang Wang Desert Research Institute 2215 Raggio Parkway Reno NV 89512 USA Institute of Earth Environment Chinese Academy of Sciences 10 Fenghui South Road Xi'an High Tech Zone Xi'an 710075 China San Diego Air Pollution Control District San Diego CA USA. California Air Resources Board El Monte CA USA. Gwangju Institute of Science and Technology Gwangju Korea.

Size distributions of ambient aerosols at the Fresno Supersite were measured with four commercially available scanning mobility particle sizers （SMPS）. TSI nano, TSI standard, Grimm, and MSP instruments were collocated at the Fresno Supersite and particle size distributions were measured continuously from August 18 through September 18, 2005. For particles with diameters between 10 and 200 nm, differences among hourly-average ambient particle concentrations ranged from 0% between the TSI nano and Grimm in the 30-50 nm size range to 39% between the Grimm and MSP in the 10-30 nm size range. MSP concentrations were 10-33% lower than those measured with the TSI standard for particles smaller than 200 nm. The TSI nano and TSI standard agreed to within 5% in their overlapping size range （10-84 nm）. The TSI nano and Grimm agreed to within 40% for 5-10 nm particles.

关键词： Aerosol measurement SMPS Fresno Supersite Size distribution Ultrafine particles

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OCA认证考试指南(1Z0-062)

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作者： (美)john watson

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Quantitative assessment of energy changes in underground coal excavations using numerical approach

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Geohazard Mechanics 2023年第1期1卷 58-68页

作者： Chunchen Wei Chengguo Zhang Onur Vardar john watson Ismet Canbulat School of Minerals and Energy Resources Engineering University of New South WalesSydneyNSW2052Australia

Coal burst is caused by a dynamic and unstable release of energy within the overstressed rock mass/coal during the mining *** the occurrence of coal burst is a result of the complex impacts of many factors,a major component of coal burst mechanism is associated with energy storage and *** study reviewed the sources of energy that can contribute to a coal burst,principally strain and potential energy stored in the coal mass around excavations,and radiated seismic energy released by geological *** energy balance concept proposed by[1]was utilised in numerical modellings to compute the radiated seismic energy in a modelling system and the kinetic energy of ejected rock/coal for a given burst *** modelling results showed that the strain energy density(SED)around excavations increases with increasing mining depth and the maximum SED area migrates deeper into the *** the effect of geological features on both roadway and longwall face,the coal burst risk proneness can be assessed considering the proposed energy *** to the results of energy changes in excavations,the modelling predicts that for depths of ejection 2 m and 3 m the kinetic energy of a burst increases as the mining depth increases from 100 m to 1000 m,but for depth of ejection 1 m only increases until mining depth reaches 700 m and then *** proposed energy-based model indicators can deepen the understanding of energy changes and the associated coal burst risks for different mining conditions.

关键词： Coal burst Energy changes Numerical approaches

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