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Refractory black carbon aerosols in rainwater in the summer of 2019 in Beijing:Mass concentration,Size distribution and wet scavenging ratio

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Journal of Environmental Sciences 2023年第10期132卷 31-42页

作者： Shandong Lei Baozhu Ge Hang Liu Jiannong Quan Danhui Xu Yuting Zhang Weijie Yao Lu Lei Yu Tian Qi Liao Xiaoyong Liu Jie Li Jinyuan Xin Yele Sun Pingqing Fu Junji Cao Zifa Wang Xiaole Pan State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China National Center for Climate Change Strategy and International Cooperation Ministry of Ecology and EnvironmentBeijing 100035China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100190China

Black carbon(BC)aerosols in the atmosphere play a significant role in climate systems due to their strong ability to absorb solar radiation.The lifetime of BC depends on atmospheric transport,aging and consequently on wet scavenging processes(in-cloud and below-cloud scavenging).In this study,sequential rainwater samples in eight rainfall events collected in 2 mm interval were measured by a tandem system including a single particle soot photometer(SP2)and a nebulizer.The results showed that the volume-weighted average(VWA)mass concentrations of refractory black carbon(rBC)in each rainfall event varied,ranging from 10.8 to 78.9μg/L.The highest rBC concentrations in the rainwater samples typically occurred in the first fraction from individual rainfall events.The geometric mean median mass-equivalent diameter(MMD)decreased under precipitation,indicating that rBC with larger sizes was relatively aged and preferentially removed by wet scavenging.A positive correlation(R2=0.73)between the VWA mass concentrations of rBC in rainwater and that in ambient air suggested the important contribution of scavenging process.Additionally,the contributions of in-cloud and below-cloud scavenging were distinguished and accounted for 74%and 26%to wet scavenging,respectively.The scavenging ratio of rBC particles was estimated to be 0.06 on average.This study provides helpful information for better understanding the mechanism of rBC wet scavenging and reducing the uncertainty of numerical simulations of the climate effects of rBC.

关键词： Refractory black carbon Wet deposition Size distribution

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Year-round observation of atmospheric inorganic aerosols in urban Beijing:Size distribution,source analysis,and reduction mechanism

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Journal of Environmental Sciences 2022年第4期34卷 354-364页

作者： Xi Zhang Jinhe Wang Kai Zhang Xiaona Shang Masahide Aikawa Guanhua Zhou Jie Li Huanhuan Li State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Resources and Environment Innovation Research Institute School of Municipal and Environmental EngineeringShandong Jianzhu UniversityJinan 250101China Faculty of Environmental Engineering The University of Kitakyushu1-1 HibikinoWakamatsuKitakyushuFukuoka 808-0135Japan School of Instrumentation Science and Opto-electronics Engineering Beihang UniversityBeijing 100191China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3) Department of Environmental Science and EngineeringFudan UniversityShanghai 200438China

To investigate particle characteristics and find an effective measure to control severe particle pollution,year-round observation of size-segregated inorganic aerosols was conducted in Beijing fromJanuary to December,2016.The sampled atmospheric particles all presented bimodal Size distribution at four pollution levels(clear,slight pollution,moderate pollution and severe pollution),and peak values appeared at the size range of 0.7-2.1μmand>9.0μm,respectively.As dominant particle compositions,NO_(3)^(-),SO_(4)^(2-),and NH_(4)^(+)in four pollution levels all showed significant peaks in fine mode,especially at the size range of 1.1-2.1μm.Secondary inorganic aerosols accounted for about 67.6%(36.3%(secondary sulfates)+31.3%(secondary nitrates))of the total sources of fine particles in urban Beijing.Severe pollution of fine particles was mainly caused by the air masses transported from nearby western and southern areas,which are industrial and densely populated region,respectively.Sensitivity tests further revealed that the control measures focusing on ammonium emission reduction was the most effective for particle pollution mitigation,and fine particles all showed nonlinear responses after reducing ammonium,nitrate,and sulfate concentrations,with the fitting curves of y=-120.8x-306.1x^(2)+290.2x^(3),y=-43.5x-67.8x^(2),and y=-25.8x-110.4x^(2)+7.6x^(3),respectively(y and x present fine particle mass variation(μg/m3)and concentration reduction ratio(CRR)/100(dimensionless)).Overall,our study presents useful information for understanding the characteristics of atmospheric inorganic aerosols in urban Beijing,as well as offers policy makers with effective measure for mitigating particle pollution.

关键词： Size distribution Secondary inorganic ions Source analysis Secondary formation Sensitivity test

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Effects of process parameters on the growth behavior and granule Size distribution of iron ore mixtures in a novel high-shear granulator

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International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2152-2161页

作者： Yang You Jiabao Guo Gang Li Zhuang Zheng Yong Li Xuewei Lü College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium–Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

This work proposes a novel horizontal high-shear granulator for iron ore granulation before sintering process.The granulation behavior such as growth process and structure of granules were firstly analyzed,followed by the effects of operation conditions such as water content,initial particle Size distribution,and the concentrate ratio.The results show that the granule size increased significantly with increasing the granulation time,and the structure of granule can be divided into three types:non-nuclei,single-nuclei,and multi-nuclei.Water promotes the coalescence and growth of particles,and a better granulation performance was obtained at the water content of 8.8wt%under the current raw material conditions.Increasing the nuclei particle ratio led to an increase in average size of granules and permeability of the granules bed,but a decrease in growth index.Besides,with increasing of concentrate ratio,granulation performance such as granule size,bed permeability,and uniformity became worse.

关键词： horizontal high-shear granulation iron ore granule structure granulation performance Size distribution

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Size distribution and chemical characteristics of particles from crop residue open burning in North China

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Journal of Environmental Sciences 2021年第11期33卷 66-76页

作者： Tingkun Li Qili Dai Xiaohui Bi Jianhui Wu Yufen Zhang Yinchang Feng State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin300350China.

Crop residue open burning is an important emission source of ambient particles in China.This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China(corn,wheat,and rice).Particle samples size ranging from 0.006–9.890μm were collected by an Electrical Low Pressure Impactor plus,a high size-resolution instrument capable of dividing particles into 14 size stages.The Size distributions of organic carbon(OC),elemental carbon(EC),water-soluble ions,and elements were analyzed,and source chemical profiles were constructed for PM0.1,PM1,PM2.5,and PM10.The number concentration of particles was concentrated in the Aiken nuclei mode(0.006–0.054μm),accounting for 75%of the total number,whereas the mass concentration was concentrated in the accumulation mode(0.054–0.949μm),accounting for 85.43%of the mass loading.OC,EC,Cl−,and K(include total K and water-soluble K)were the major chemical components of the particles,whose mass percentage distributions differed from those of other components.These fivemain components exhibited a bell-shaped Size distribution in the 0.006–9.890μm range,whereas the other components exhibited a U-shaped distribution.Among the chemical profiles for PM0.1–PM10,OC was the most important component at 10–30%,followed by EC at 2%–8%.The proportions of K^(+),Cl^(−),and K varied substantially in different experimental groups,ranging from 0–15%,and K+and Cl−were significantly correlated(r=0.878,α=0.000).

关键词： Crop residue Open burning Size distribution Source profile Electrical Low Pressure Impactor plus(ELPI+)

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Size distribution and source of heavy metals in particulate matter on the lead and zinc smelting affected area

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Journal of Environmental Sciences 2018年第9期30卷 188-196页

作者： Kai Zhang Fahe Chai Zilong Zheng Qing Yang Xuecai Zhong Khanneh Wadinga Fomba Guangzhu Zhou State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing 100022China College of Chemical and Environmental Engineering Shandong University of Science and Technology Qingdao 266590 China Zhuzhou Environment Monitoring Center Zhuzhou 412000 China Leibniz-Institute for Tropospheric Research (FROPOS) Leipzig 04318 Germany

In order to understand the Size distribution and the main kind of heavy metals in particulate matter on the lead and zinc smelting affected area, particulate matter （PM） and the source samples were collected in Zhuzhou, Hunan Province from December 2011 to January 2012 and the results were discussed and interpreted. Atmospheric particles were collected with different sizes by a cascade impactor. The concentrations of heavy metals in atmospheric particles of different sizes, collected from the air and from factories, were measured using an inductively coupled plasma mass spectrometry （ICP-MS）. The results indicated that the average concentration of PM, chromium （Cr）, arsenic （As）, cadmium （Cd） and lead （Pb） in PM was 177.3 ± 33.2 μg/m^3, 37.3 ± 8.8 ng/m^3, 17.3 ± 8.1 ng/m^3, 4.8 ± 3.1 ng/m^3 and 141.6 ± 49.1 ng/m^3, respectively. The Size distribution of PM displayed a bimodal distribution; the maximum PM Size distribution was at 1.1-2.1 μm, followed by 9-10 μm. The Size distribution of As, cd and Pb in PM was similar to the distribution of the PM mass, with peaks observed at the range of 1.1-2.1 μm and 9-10 μm ranges while for Cr, only a single-mode at 4.7-5.8 μm was observed. PM （64.7%, As （72.5%）, cd （72.2%） and Pb （75.8%） were associated with the fine mode below 2.1 μm, respectively, while Cr （46.6%） was associated with the coarse mode. The Size distribution characteristics, enrichment factor, correlation coefficient values, source information and the analysis of source samples showed that As, Cd and Pb in PM were the typical heavy metal in lead and zinc smelting affected areas, which originated mainly from lead and zinc smelting sources.

关键词： Atmospheric particulate matter Size distribution Heavy metals Pollution characteristics Lead and zinc smelting

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The Size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

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Frontiers of Environmental Science & Engineering 2021年第3期15卷 87-96页

作者： Min Gao Ziye Yang Yajie Guo Mo Chen Tianlei Qiu Xingbin Sun Xuming Wang Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology Beijing Agro-Biotechnology Research CenterBeijing Academy of Agriculture and Forestry SciencesBeijing 100097China College of Forestry Northeast Forestry UniversityHarbin 150040China

Composting plants are regarded as one of the important sources of environmental bioaerosols.However,limitations in the Size distribution of airborne bacteria have prevented our comprehensive understanding of their risk to human health and their dispersal behavior.In this study,different sizes of airborne bacteria were collected using an eight-stage impactor from a full-scale composting facility.size-related abundance and communities of airborne bacteria as well as human pathogenic bacteria(HPB)were investigated using 16S rRNA gene sequencing coupled with droplet digital PCR.Our results indicate that the bacterial concentrations from the eight stages were approximately 10^(4)-105copies/m^(3).Although no statistical correlation was detected between the particle size and the Shannon index,the influence of size on bacterial lineages was observed in both composting and packaging areas.For airborne bacteria from different stages,the dominant phyla were Firmicutes,Proteobacteria,and Actinobacteria,and the dominant genera was Bacillus.Seven out of eight HPB with a small geometric mean aerodynamic diameter had a high concentration in composting areas.Based on diameters of 2.42 to 5.09μm,most HPB in the composting areas were expected to be deposited on the bronchus and secondary bronchus.However,in the packaging areas,the deposition of HPB(diameters 3.70 to 8.96μm)occurred in the upper part of the respiratory tract.Our results on the Size distribution,abundance,and diversity of these bacteria offer important information for the systematic evaluation of bacterial pathogenicity and the potential health impacts on workers in composting plants and the surrounding residents.

关键词： Size distribution Airborne bacteria Biological diversity Human pathogenic bacteria Composting plants

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Seasonal variation and Size distribution of biogenic secondary organic aerosols at urban and continental background sites of China

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Journal of Environmental Sciences 2018年第9期30卷 32-44页

作者： Yanqin Ren Gehui Wang Jianjun Li Can Wu Cong Cao Jiayuan Wang Lu Zhang Fan Meng Hong Li State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710061 China. Key Laboratory of Geographic Information Science of the Ministry of Education School of Geographic Sciences East China Normal UniversityShanghai 200041 China Center of Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China University of Chinese Academy of Sciences Beijin9 100049 China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing 100012 China

size-resolved biogenic secondary organic aerosols （BSOA） derived from isoprene and monoterpene photooxidation in Qinghai Lake, Tibetan Plateau （a continental background site） and five cities of China were measured using gas chromatography/mass spectrometry （GC/MS）. Concentrations of the determined BSOA are higher in the cities than in the background and are also higher in summer than in winter. Moreover, strong positive correlations （R^2 = 0.44-0.90） between BSOA and sulfate were found at the six sites, suggesting that anthropogenic pollution （i.e., sulfate） could enhance SOA formation, because sulfate provides a surface favorable for acid-catalyzed formation of BSOA. Size distribution measurements showed that most of the determined SOA tracers are enriched in the fine mode （〈3.3 μm） except for cis-pinic and cis-pinonic acids, both presented a comparable mass in the fine and coarse （〉3.3 μm） modes, respectively. Mass ratio of oxidation products derived from isoprene to those from monoterpene in the five urban regions during summer are much less than those in Qinghai Lake region. In addition, in the five urban regions relative abundances of monoterpene oxidation products to SOA are much higher than those of isoprene. Such phenomena suggest that BSOA derived from monoterpenes are more abundant than those from isoprene in Chinese urban areas.

关键词： Biogenic secondary organic aerosols Photochemical oxidation Seasonal and spatial variations Size distribution Sulfate

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Particulate Amines in the Background Atmosphere of the Yangtze River Delta,China:Concentration,Size distribution,and Sources

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Advances in Atmospheric Sciences 2021年第7期38卷 1128-1140页

作者： Wei DU Xinpei WANG Fengqin YANG Kaixu BAI Can WU Shijie LIU Fanglin WANG Shaojun LV Yubao CHEN Jinze WANG Wenliang LIU Lujun WANG Xiaoyong CHEN Gehui WANG Key Laboratory of Geographic Information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China School of Ecological and Environmental Sciences East China Normal UniversityShanghai 200241China Institute of Eco-Chongming Shanghai 200062China

Amines are important for new particle formation and subsequent growth in the atmosphere.Consequently,the processes involved are receiving more attention in recent years.Here,we conduct a field observation in order to investigate the atmospheric particulate amines at a background site in the Yangtze River Delta(YRD)during the summer of 2018.Four amines in PM_(2.5),i.e.,methylamine(MA),dimethylamine(DMA),diethylamine(DEA),and trimethylamine(TMA),were collected,twice daily and analyzed.During the campaign,our measurements found the concentrations of MA,DMA,DEA,and TMA of 15.0±15.0,6.3±6.9,20.4±30.1,and 4.0±5.9 ng m^-(3),respectively,and the four amines correlated well with each other.The concentration of amines appear to be independent of whether they were collected during the day or night.Both MA and DMA exhibited a bimodal Size distribution that had peaks at 0.67 and 1.1μm,suggesting amines preferably distribute on submicron particles.Boundary layer height(BLH),relative humidity,and pH of aerosols were found have a negative relationship with amines,while aerosol liquid water content(ALWC)was found to have a positive relationship with amines.The PMF(positive matrix factorization)source apportionment results showed that the main source of amines in Chongming Island was of anthropogenic origin such as industrial and biomass emission,followed by marine sources including sea salt and marine biogenic sources.Given that the YRD region is still suffering from complex atmospheric pollution and that the knowledge on aerosol amines is still limited,more field studies are in urgent need for a better understanding of the pollution characteristics of amines.

关键词： particulate amines Yangtze River Delta PM_(2.5) Size distribution source

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Effects of high pressure roller grinding on Size distribution of vanadium-titanium magnetite concentrate particles and improvement of green pellet strength

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Journal of Iron and Steel Research(International) 2017年第3期24卷 266-272页

作者： Feng Chen Yu-feng Guo Tao Jiang Fu-qiang Zheng Shuai Wang Ling-zhi Yang School of Minerals Processing and Bioengineering Central South University Changsha 410083 Hunan China

The vanadium-titanium magnetite concentrate from Panxi region of China was pretreated by high pressure roller grinding（ HPRG） and then used in pelletization. Size distribution change of the vanadiumtitanium magnetite concentrate after HPRG and the improvement of its green pellet strength were investigated. The results indicated that,besides the increase of fine particles,the vanadium-titanium magnetite concentrate after HPRG had a smaller size ratio of fine particle to coarse particle of 0. 126,meaning a lower porosity,compared with the size ratio of raw material of 0. 157. The concentrate particles were more closely packed when there was a smaller size ratio of fine particle to coarse particle. The particle packing in the green pellets was closer after HPRG,which strengthened the green pellets with an average drop number of 5. 1（ drop height of 0. 5 m） and average compressive strength of 13. 1 N per pellet of 11 mm in diameter.

关键词： High pressure roller grinding Particle packing Size distribution size ratio Green pellet strength

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Effect of particle Size distribution on magnetic behavior of nanoparticles with uniaxial anisotropy

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Chinese Physics B 2018年第9期27卷 572-576页

作者： S Rizwan Ali Farah Naz Humaira Akber M Naeem S Imran Ali S Abdul Basit M Sarim Sadaf Qaseem Department of Physics Federal Urdu University of Arts Science and Technology Department of Applied Chemistry and Chemical Technology University of Karachi Department of Computer Science Federal Urdu University of Arts Science and Technology

The effect of particle Size distribution on the field and temperature dependence of the hysteresis loop features like coercivity（HC）, remanence（MR）, and blocking temperature（TB） is simulated for an ensemble of single domain ferromagnetic nanoparticles with uniaxial anisotropy. Our simulations are based on the two-state model for T 〈 TB and the metropolis Monte-Carlo method for T 〉 TB. It is found that the increase in the grain size significantly enhances HC and TB. The presence of interparticle exchange interaction in the system suppresses HC but causes MRto significantly increase.Our results show that the parameters associated with the particle Size distribution（D（d,δ）） such as the mean particle size d and standard-deviation δ play key roles in the magnetic behavior of the system.

关键词： magnetic nanoparticles Monte Carlo simulations Size distribution interparticle interaction hysteresis

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