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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)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

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

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

Source apportionment of atmospheric particulate carbon in Las Vegas,Nevada,USA

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Particuology 2013年第1期11卷 110-118页

作者： Mark c.Green judith c.chow M.-c.Oliver chang L.-W.Antony chen Hampden D.Kuhns Vicken R.Etyemezian John G.Watson Division of Atmospheric Sciences Desert Research Institute2215 Raggio ParkwayRenoNV 89512USA Division of Atmospheric Sciences Desert Research Institute.2215 Raggio ParkwayRenoNV 89512USA State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'anChina california Air Resources Board 9528 Telstar Ave.El MonteCA 91731USA

A study was conducted to quantify wintertime contributions of source types to carbonaceous PM2.5 at four urban sites in the Las Vegas Valley, one of the most rapidly growing urban areas in the southwestern United States. Twenty-four hour average ambient samples were collected for mass, ions, elements, organic carbon （Oc）, elemental carbon （Ec）, and trace organic markers analysis. Additional measurements were made to determine diurnal patterns in light-absorbing black carbon （Bc） as a marker for combustion sources. carbonaceous PM sources of on-road gasoline vehicles, on-road diesel vehicles, and off-road diesel engines were characterized with their chemical profiles, as well as fuel-based emission factors, using an In-Plume Sampling System. The Effective Variance chemical Mass Balance （EV-cMB） source apportionment model was applied to the ambient samples collected, using source profiles developed in this study as well as profiles from other relevant studies. Four main sources contributed to PM2.5 carbon within the Las Vegas Valley：（1） paved road dust, （2） on-road gasoline vehicles, （3） residential wood combustion, and （4） on-road diesel vehicles. cMB estimated that on-road mixed fleet gasoline vehicles are the largest source for Oc and Ec at all the sites. The contribution of paved road dust to both Oc and Ec was 5-10% at the four sites. On-road diesel vehicles contribute 22% of the Oc and 34% of the Ec at a site near the city center, which is located immediately downwind of a major freeway. Residential wood combustion is a more important source than on-road diesel vehicles for two residential neighborhood sites, These results are consistent with our conceptual model, and the research methodology may be applied to studying other urban areas.

关键词： Source characterization Mobile sources Elemental carbon Source apportionment Organic marker

Enhanced characterization for PM2.5 Source Apportionment

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Enhanced Characterization for PM2.5 Source Apportionment

New Approaches in Multiple Pollutant Air Quality Management

第十五届海峡两岸气胶技术研讨会

作者： judith c.chow John G.Watson Division of Atmospheric Sciences Desert Research Institute Nevada System of Higher Education

PM speciation networks normally quantify elements,water-soluble ions,and carbon *** have proven useful for identifying sources and quantifying their contributions to PM ***,they are limited in separating source sub-types,such as diesel *** exhaust,smoldering *** biomass combustion,secondary organic aerosols,fugitive dusts,

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New Approaches in Multiple Pollutant Air Quality Management

2003年秋冬季西安大气中有机碳和元素碳的理化特征及其来源解析

第八届海峡两岸气溶胶技术研讨会暨第三届空气污染技术研讨会

作者： judith c.chow John G.Watson Desert Research Institute Reno NV USA

The single-pollutant air quality management strategy carried out for the past 50 years has resulted in a continuous reduction in source emissions and ambient concentrations in developed countries. However,air pollution consists of a mixture of different substances,and the effects of this mixture may be greater than the sum of their parts. Few source types emit a single pollutant,and more cost-effective and beneficial effects might be achieved by controlling this mixture rather than its individual components. A prime example is the integration of climate-forcing pollutants into current air quality management systems. As the effects of individual pollutants become more difficult to detect,a framework for multi-pollutant air quality management must be developed. This framework should include broad assessment tools that quantify co-benefits of multiple pollutant reductions on health,material and ecosystem damage,visibility degradation,and global warming. Emissions need to be assessed over a product’s entire life cycle for global air quality management,but these must be integrated with local and regional assessments to quantify human exposure and health risks. Several indicators and software tools are currently used for these purposes,but their input data and simplifying assumptions are poorly documented and uncertainties are large. On a more practical basis,movement toward multi-pollutant air quality management could begin with adapting more cost-effective multi-pollutant measurement technologies to source and ambient monitoring. current test methods are dominated by single pollutant techniques that are limiting and costly. Many advanced air quality models already address a large number of pollutants,but in current use they are optimized for a single pollutant and only applied to situations that show excessive levels for that pollutant. The transition from single-pollutant/single-effect to multi-pollutant/multi-effect will take decades,but it won’t start until a roadmap

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自然科学进展 2005年第12期15卷 1460-1466页

作者：曹军骥李顺诚李杨 judith c.chow Kochy Fung 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710075 香港理工大学 Desert Research Institute AtmAA Inc.calabasas CAUSA

2003年9月至2004年2月在西安站点开展了大气PM2．5和PM10中碳气溶胶的连续观测,并采集了三类主要污染来源样品(燃煤,机动车尾气和生物质燃烧)进行对比分析,采用IMPROVE-TOR 方法准确地测量了样品的有机碳(Oc),元素碳(Ec)及其中的8个碳... 详细信息

2003年9月至2004年2月在西安站点开展了大气PM2．5和PM10中碳气溶胶的连续观测,并采集了三类主要污染来源样品(燃煤,机动车尾气和生物质燃烧)进行对比分析,采用IMPROVE-TOR 方法准确地测量了样品的有机碳(Oc),元素碳(Ec)及其中的8个碳组分含量．西安秋季和冬季大气 PM2．5中Oc的平均含量ρOc分别为(34．1±18．0),(61．9±33．2)μg·m-3,Ec的平均含量ρEc为 (11．3±6．9),(12．3±5．3)μg·***和Ec均主要赋存于PM2．5粒级中．秋季Oc和Ec的相关性好(R2>0．90),冬季一般(R2=0．66)．总碳气溶胶在秋季PM2．5中占(48．8±10．1)％,在冬季也达到了(45．9±7．5)％．所有观测日的ρOc／ρEc比值均大于2．0,秋季PM2．5中ρOc／ρEc平均为3．3,冬季为 5．1,这可能主要与直接排放来源有关．由碳气溶胶的8个碳组分数据,采用绝对主分量分析获得了主要排放来源对总碳的贡献份额,即秋季汽油车尾气占73％,柴油车尾气占23％,生物质燃烧占 4％,而冬季燃煤占了44％,汽油车尾气占44％,生物质燃烧占9％,柴油车占3％。

关键词：有机碳元素碳气溶胶来源解析

Evolution of Measurements for Air Quality Management

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Evolution of Measurements for Air Quality Management

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

第十五届海峡两岸气胶技术研讨会

作者： John G.Watson judith c.chow George M.Hidy Division of Atmospheric Sciences Desert Research Institute Nevada System of Higher Education Envair/Aerochem

＜正＞Air quality measurements include sampling and quantitation,data integrity,documentation,network design,sponsorship and operations,and archiving and accessing for *** of these components has evolved and advanced over the last 200 years as knowledge of atmospheric chemistry and physics has *** quality was first detected by what people could see smoke and smell contaminated *** pollutants were found to react with certain materials or

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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