Gravimetric analysis for PM2.5 mass concentration based on year-round monitoring at an urban site in Beijing

2016 ◽  
Vol 40 ◽  
pp. 154-160 ◽  
Author(s):  
Yanli Wang ◽  
Wen Yang ◽  
Bin Han ◽  
Wenjie Zhang ◽  
Mindong Chen ◽  
...  
2020 ◽  
Vol 64 (8) ◽  
pp. 876-889
Author(s):  
Candace Su-Jung Tsai ◽  
Nara Shin ◽  
Jürgen Brune

Abstract Concerns have been raised regarding small respirable particles, i.e. sub-micrometer-sized particles, associated with mining activities. This evaluation was designed to investigate the emissions from jackleg drilling and diesel engines and to characterize the nature of emitted particles using gravimetric analysis and number metrics. The mass concentration to which workers are potentially exposed was determined from a 4-h sampling in the vicinity of drilling activities in an underground metal mine; this concentration was found to be lower than 0.6 mg m−3 of total respirable dust. This mass concentration is low; however, the number concentrations of emitted particles from drilling exceeded 1 × 106 particles cm−3 in areas 7–9 m downwind from the drilling operation. Sub-micrometer-sized particles were also observed in aerosol samples collected using a specialized sampler, and various elements associated with drilling were found among these emitted particles. Finally, the particles in the diesel exhaust were collected, and the exhaust was found to contain nanometer-sized particles.


2014 ◽  
Vol 14 (6) ◽  
pp. 2887-2903 ◽  
Author(s):  
J. K. Zhang ◽  
Y. Sun ◽  
Z. R. Liu ◽  
D. S. Ji ◽  
B. Hu ◽  
...  

Abstract. In January 2013, Beijing experienced several serious haze events. To achieve a better understanding of the characteristics, sources and processes of aerosols during this month, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site between 1 January and 1 February 2013 to obtain the size-resolved chemical composition of non-refractory submicron particles (NR-PM1). During this period, the mean measured NR-PM1 mass concentration was 89.3 ± 85.6 μg m−3, and it peaked at 423 μg m−3. Positive matrix factorization (PMF) differentiated the organic aerosol into five components, including a highly oxidized, low-volatility oxygenated organic aerosol (LV-OOA), a less oxidized, semi-volatile oxygenated OA (SV-OOA), a coal combustion OA (CCOA), a cooking-related OA (COA), and a hydrocarbon-like OA (HOA), which on average accounted for 28%, 26%, 15%, 20% and 11% of the total organic mass, respectively. A detailed comparison between the polluted days and unpolluted days found many interesting results. First, the organic fraction was the most important NR-PM1 species during the unpolluted days (58%), while inorganic species were dominant on polluted days (59%). The OA composition also experienced a significant change; it was dominated by primary OA (POA), including COA, HOA and CCOA, on unpolluted days. The contribution of secondary OA (SOA) increased from 35% to 63% between unpolluted and polluted days. Second, meteorological effects played an important role in the heavy pollution in this month and differed significantly between the two types of days. The temperature and relative humidity (RH) were all increased on polluted days and the wind speed and air pressure were decreased. Third, the diurnal variation trend in NR-PM1 species and OA components showed some differences between the two types of days, and the OA was more highly oxidized on polluted days. Fourth, the effects of air masses were significantly different between the two types of days; air was mainly transported from contaminated areas on the polluted days. The comparison also found that the aerosol was more acidic on polluted days. Additionally, the variation trends of the mass concentration and mass fractions of NR-PM1 species and OA components were more dramatic when the NR-PM1 mass loading was at a higher level. The serious pollution observed in this month can be attributed to the synergy of unfavorable meteorological factors, the transport of air masses from high-pollution areas, emission by local sources, and other factors.


Author(s):  
Raminta Vyzienė ◽  
Aloyzas Girgždys

Though some authors declare that aerosol number concentration might be a better indicator of health effects of the particulates than the mass method, there is lack of aerosol number investigation studies. Most of air quality studies so far have been based on aerosol mass concentration measurements. Lithuanian National Air Quality Monitoring Network does not carry out aerosol number concentration measurements. Nonetheless, detailed particulate matter mass concentration investigation studies are made periodically in the biggest Lithuanian cities by various scientific organizations. Jonava seems to be overpassed even there. This is the reason for choosing the investigation object. In Jonava town persistent measurements of aerosol number concentration were performed since 21 till 29 of November in the year 2006. The pollutants were measured with an optical particle counter AZ‐5. The fluctuations of 24 hours, diurnal aerosol number concentration were analysed. The weather was favorable for pollutant accumulation and stood quite stable during the experimental period. The variation of aerosol number concentration was compared with other pollutants and wind speed changes. The increase of aerosol number concentration was detected with the decrease of wind speed and vice versa. The biggest concentration was detected when the wind blew from the South, there green territories are located. The increase of particulate concentration was not observed with the South‐eastern wind directions coming from a fertilizer plant. The correlation between aerosol number concentration and nitrogen compounds was found. The tendency for high aerosol number concentrations was not observed during the rush hours as well as weekend effect could not be detected, indicating about low impact of local transportation. Comparison between particulate matter (PM10) mass and aerosol number concentrations was performed. The linear tendency between aerosol number and mass concentration was found. The increase of PM10 mass concentration was found to be 1,6 μg/m3 for each additional 1000 aerosol particle cm−3. While comparing aerosol number concentration fluctuations in Jonava and Preila locations, the results exhibited great variability on both monitoring sites. Aerosol number concentration was higher in Preila in February, March and April. Meanwhile, in summer months the aerosol number concentration increased on the urban site. These urban and rural differences were influenced by geographical and meteorological site peculiarities and air mass transport. Santrauka Nors kai kurie autoriai teigia, kad aerozolių skaitinė koncentracija gali būti geresnis indikatorius, vertinant kietųjų dalelių įtaką sveikatai nei masinė koncentracija, aerozolio skaitinės koncentracijos tyrimų trūksta. Daugelis oro kokybės tyrimų remiasi kietųjų dalelių masinės koncentracijos matavimais. Didžiuosiuose Lietuvos miestuose masinės kietųjų dalelių koncentracijos tyrimai atliekami periodiškai įvairių mokslinių organizacijų. Kietųjų dalelių tyrimų Jonavoje trūkumas lėmė tyrimo objekto pasirinkimą. Aerozolių skaitinė koncentracija nenutrūkstamai buvo matuojama Jonavoje lapkričio 21– 29 dienomis optiniu dalelių skaičiuotuvu AZ-5. Vėliau gauti duomenys buvo analizuojami, stebimi valandiniai ir paros skaitinės koncentracijos kitimai per visą matavimo laikotarpį. Buvo tiriama sąsaja tarp skaitinės aerozolių koncentracijos ir kitų teršalų bei vėjo greičio. Nustatyta priklausomybė tarp aerozolių skaitinės koncentracijos ir azoto junginių, taip pat vėjo greičio. Oro sąlygos teršalų kaupimuisi matavimo laikotarpiu buvo palankios, viso eksperimento metu gana pastovios, todėl staigūs aerozolių koncentracijos pokyčiai negali būti siejami su netikėtais oro sąlygų pokyčiais. Vis tik aerozolių skaitinės koncentracijos padidėjimas nustatytas mažėjant vėjo greičiui, ir atvirkščiai. Didžiausios koncentracijos užfiksuotos pučiant pietų vėjui iš periferijos. Gi pučiant rytų vėjui, nešančiam oro mases nuo trąšų fabriko, koncentracijos netgi sumažėjo. Aerozolių skaitinės koncentracijos padidėjimo neužfiksuota rytinių ir vakarinių transporto pikų metu. Nebuvo nustatytas ir „savaitgalio efektas“. Tai byloja apie nežymią vietos transporto įtaką matavimo rezultatams. Tarp aerozolių masinės ir skaitinės koncentracijų rasta tiesinė priklausomybė. Nustatyta, kad aerozolių skaitinei koncentracijai padidėjus 1000 dalelių/cm3, aerozolių masinė koncentracija padidėja 1,6 μm/m3 Lyginant kietųjų dalelių (PM10) masinės koncentracijos kitimą miesto ir kaimo vietovėse, pastebėta didelis rezultatų skirtumas. Aerozolių skaitinė koncentracija buvo žymiai didesnė Preiloje vasario – balandžio mėnesiais, palyginti nei Jonavoje. Vasarą kietųjų dalelių masinė koncentracija buvo didesnė miesto aplinkoje. Šiuos kietųjų dalelių koncentracijų skirtumus kaimo ir miesto aplinkoje lemia geografiniai bei meteorologiniai vietovių skirtumai. Įvertinus tyrimo duomenis paaiškėjo, kad kietųjų dalelių koncentracijų kaitą eksperimento metu Jonavoje labiausiai lėmė tolimieji oro teršalai. Vietinių taršos šaltinių įtaka kietųjų dalelių koncentracijų pasiskirstymui eksperimento metu nebuvo esminė. Резюме По мнению некоторых авторов, числовая концентрация аэрозоля может быть лучшим индикатором воздействия твердых частиц на здоровье людей, чем массовый метод, однако она недостаточно исследована. Большинство исследований качества воздуха пока основано на измерении массовой концентрации макрочастиц. В больших городах Литвы исследования массовой концентрации твердых частиц осуществляются различными научными организациями периодически. В Йонаве таких исследований было недостаточно. Постоянные измерения концентрации числа аэрозоля в городе были выполнены с 21 по 29 октября 2006 г. Загрязнители были измерены фотоэлектрическим счетчиком аэрозольных частиц АЗ-5. Суточные и часовые колебания числовой концентрации аэрозоля были проанализированы. Исследовалась связь между числовой концентрацией аэрозолей и других загрязнителей и скоростью ветра. Была найдена корреляция между числовой концентрацией аэрозоля, соединениями азота и скоростью ветра. Увеличение числовой концентрации аэрозоля было установлено с уменьшением скорости ветра и наоборот. Высокая числовая концентрация аэрозолей не нaблюдaлась в часы «пик» утром и вечером. В этом же отношении не был установлен эффект конца недели из-за небольшого воздействия местного транспорта на результаты измерений. Была установлена линейная зависимость между числовой и массовой концентрацией аэрозоля. С увеличением числовой концентрации на 1000 частиц аэрозоля на 1 см3 массовая концентрация PM10 увеличивается на 1,6 μм/м3 . Сравнение колебаний числовой концентрации аэрозоля в Йонаве и Прейле выявило большую изменчивость результатов. Числовая концентрация аэрозоля в Прейле была выше в феврале, марте и апреле, а в летние месяцы она увеличивалась на городском участке. Эти городские и сельские различия объясняются особенностями географических и метеорологических участков и движением транспорта.


2013 ◽  
Vol 117 (1-2) ◽  
pp. 133-147 ◽  
Author(s):  
Parth S. Mahapatra ◽  
Sipra Panda ◽  
Namrata Das ◽  
Satyajit Rath ◽  
Trupti Das

2018 ◽  
Vol 2 (1) ◽  
pp. 13
Author(s):  
Walter Manuel Vicharra ◽  
Carlos Cabrera

The main objective of esta research is to determine the level of concentration of particulate materials of the size of 10 microns and 2.5 microns of an artisanal foundry, and to Evaluate the health in workers' respiratory diseases, as well as to find a relationship Between the particulate materials and the respiratory diseases, Which the project is located in the district of San Antonio, Department of Huarochiri, Department of Lima, Peru - 2017. The gravimetric analysis method approved by the General Directorate of Environmental Health DIGESA was used, with the Protocol for air quality monitoring and data management, to determine the level of concentration of particulate material and on the other hand Health Assessments in respiratory diseases Were used a survey made by a doctor in pulmonology, Which was Then backed by medical examinations performed on workers. It was Determined That the particulate materials of 10 microns and 2.5 microns Were above environmental quality standards, Which is Considered as risky for the health of people, and in respiratory diseases it was Concluded That some of the subjects of the population of study are With occupational diseases.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (4) ◽  
pp. 29-33
Author(s):  
LEE A. GOETZ ◽  
AJI P. MATHEW ◽  
KRISTIINA OKSMAN ◽  
ARTHUR J. RAGAUSKAS

The thermal stability and decomposition of in-situ crosslinked nanocellulose whiskers – poly(methyl vinyl ether-co-maleic acid) – polyethylene glycol formulations (PMVEMA-PEG), (25%, 50%, and 75% whiskers) – were investigated using thermal gravimetric analysis (TGA) methods. The thermal degradation behavior of the films varied according to the percent cellulose whiskers in each formulation. The presence of cellulose whiskers increased the thermal stability of the PMVEMA-PEG matrix.


2003 ◽  
Vol 775 ◽  
Author(s):  
G.V.Rama Rao ◽  
Qiang Fu ◽  
Linnea K. Ista ◽  
Huifang Xu ◽  
S. Balamurugan ◽  
...  

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.


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