scholarly journals SIZE DISTRIBUTION AND CONTRIBUTION OF PARTICLES FROM RICE STRAW OPEN BURNING TO THE ATMOSPHERE IN HANOI

2020 ◽  
Vol 58 (5A) ◽  
pp. 94
Author(s):  
Thuy Chau Pham
Keyword(s):  
Size Distribution ◽  
Rice Straw ◽  
Fine Particle ◽  
Mass Concentration ◽  
Fine Particles ◽  
Sampling Site ◽  
Accumulation Mode ◽  
Open Burning ◽  
Average Mass ◽  
Sampling Campaign

Atmospheric ultrafine, accumulation mode and coarse fractions collected at representative rice straw open burning areas in Hanoi were investigated to identify characteristics of size distribution and contribution of particles emitted from rice straw (RS) burning season to the atmosphere. The sampling was conducted in two episodes: RS burning episode and RS non-burning episode at Dong Anh and Quoc Oai, in seven consecutive days for each sampling campaign from 2018 to 2019. In the RS burning episode, PM1-2.5 showed the highest fraction among all collected particles in both sampling sites, while PM2.5-10 was the most abundant in RS non-burning season. The average mass concentration of PM2.5 in RS burning period and RS non-burning period were 79.7  46.5 g m-3 and 65.2  21.9 g m-3, respectively at Dong Anh sampling site. Those values were 90.9  33.2 g m-3  in the QO_RS burning site and 71.9  29.3 g m-3  in the TM_RS non-burning site. The proportion of fine particle (PM2.5) at both sites were considerable higher in RS burning period as compared to non-burning period, while the concentration of ultrafineparticle (PM0.1) and coarse particle (PM>10m) were similar between two episodes. This result provides better understanding on size distribution and contribution of fine particles from open RS burning to the atmosphere in Hanoi, which is an useful information for the environmental managers to control RS open burning in Hanoi as well as in Vietnam. 

Long term PM2.5 trends in the Australian industrial city of Newcastle: a 15-year study from 1998 to 2013

2014 ◽  
Vol 11 (6) ◽  
pp. 644 ◽  
Author(s):  
Eduard Stelcer ◽  
David D. Cohen ◽  
Armand J. Atanacio
Keyword(s):  
Air Pollution ◽  
Fine Particle ◽  
Ion Beam ◽  
Sampling Site ◽  
Local Area ◽  
Large Dataset ◽  
Average Mass ◽  
Industrial Operations ◽  
Aerosol Sources

Environmental context Long-term exposure to fine particle air pollution has significant implications for human health. At a mixed urban–industrial site in Newcastle, Australia, we identified contributions from individual industrial aerosol sources in addition to the more common aerosol sources such as soil, sea and smoke. These results are significant for the assessment and management of fine particulate air pollution in the Newcastle air shed. Abstract A long-term, large dataset approach combining standard accelerator-based ion beam analysis (IBA) techniques with positive matrix factorisation (PMF) analysis to determine the sources and trends of fine particle pollution in the Newcastle NSW, Australia is discussed. Over 1500 samples of particle matter with aerodynamic diameter less than 2.5µm (PM2.5) were collected between February 1998 and December 2013 and analysed using IBA techniques to obtain the concentration of 22 different elements from hydrogen to lead. The PM2.5 15-year average mass at the sampling site was 8.11µgm–3. Statistical PMF analysis was applied to this large dataset to quantitatively determine nine source fingerprints; soil, secondary sulfate, sea, smoke, industrial processes (specifically related to calcium, manganese and iron) and two different automobile sources. Significant step-like reductions of 98, 79 and 69%, over and above regular seasonal variations, were clearly observed in the industrial-Mn, industrial-Fe and automobile sources during this time period. These trends showed excellent correlation with the cessation of large industrial operations in the local area and clearly demonstrate the advantage of long-term aerosol analysis for monitoring and managing fine particle air pollution sources on a local scale.

scholarly journals Distribution and Toxic Equipvalent Assessement of Polycyclic Aromatic Hydrocarbons (Pahs) in Particulate Matter Emmited from Rice Straw Open Field Burning in Hanoi

2021 ◽  
Vol 37 (2) ◽  
Author(s):  
Pham Chau Thuy ◽  
Le Huu Tuyen
Keyword(s):  
Particulate Matter ◽  
Rice Straw ◽  
Fine Particles ◽  
Health Effect ◽  
High Volume ◽  
Atmospheric Particles ◽  
Atmospheric Environment ◽  
Open Burning ◽  
Average Value ◽  
Environment And Health

This study investigated the distribution of PAHs content in particulate matter emitted from the open burning of rice straw in Hanoi. Fine particles (PM2.5) was collected using a MiniVol TAS device and the total suspended particles (TSP) was collected using a high-volume sampler Staplex. PAHs in particulate matter were analyzed by HPLC-FL with fluorescent detector. The results showed that 4-ring PAHs was dominant in particles emitted from rice straw burning, especially the most abundant PAHs was Flu: 57.8 37.1 and 64.8  34.9 µg/g in PM2.5 and TSP, respectively. However, the accumulation of PAHs with a higher rings number, especially the percentage of BaP in total 9PAHs in PM2.5 emitted from rice straw open burning was 2 times higher than that in the background samples, while the ratio of BaP in total 9PAHs in TSP from burning smoke is smaller than that of background samples. The carcinogenic potential of fine particles emitted from rice straw open burning calculated by BaPeq are 20 times higher than that of the background sample. Although the concentration of atmospheric particles - bound BaP in the present study (1.0  0.8 ng/m3) is lower than that in urban and traffic areas, the average value of BaP is still 8.7 times higher than the value recommended by the WHO. The results of this study show a picture of the toxic levels of atmospheric particles and particles emitted from rice straw open burning, providing clearer evidence to understand the adverse effects of rice straw open burning on atmospheric environment and health effect.  

ELEMENTAL COMPOSITION, SIZE DISTRIBUTION AND IMAGE INTERPRETATION OF FINE PARTICULATE MATTER IN URBAN CITY ROAD SIDES, MYSORE (KARNATKA) INDIA

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
S. SREENIVASA ◽  
G.V. VENKATARAMANA
Keyword(s):  
Particulate Matter ◽  
Elemental Composition ◽  
Size Distribution ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Sampling Site ◽  
Image Interpretation ◽  
Ambient Particulate Matter ◽  
Sem Image ◽  
Urban City

The study was carried out using vacuum air pump sampler to collect particulate matter in the urban city roadsides. Elemental composition, size distribution and image interpretation of particles was analyzed using the methods of Energy Dispersive X-Ray (EDX), Dynamic Light Scattering (DLS) and Scanning Electron Microscope (SEM), respectively. Irwin road, the highly dense traffic area in Mysore city, has been selected for study purpose due to its high vehicular emissions. EDX analysis found that roadside particulate matter was dominated by black carbon (C) about 56% affected mostly by tail end pipe emissions. The samples were also rich in crustal elements like silicon (Si), iron (Fe), calcium (Ca), aluminium (Al), sodium (Na) and potassium (K) either in single elements or as chemical compounds. The results from DLS and SEM image interpretation showed that almost 90% of ambient particulate matter collected in the sampling site was in the size of fine particles (PM2.5) and around 74% of them have degree of roundness or circularity above 0.75.

Study on Mass Concentrations and Size Distribution of Particulate Material from Incense Burning in Temples

2011 ◽  
Vol 71-78 ◽  
pp. 2740-2744
Author(s):  
Ming Shi Wang ◽  
Fan Qin ◽  
Xiao Zhang
Keyword(s):  
Size Distribution ◽  
Mass Concentration ◽  
Fine Particles ◽  
Particulate Material ◽  
Atmospheric Particulate Matter ◽  
Size Distributions ◽  
American Standard ◽  
Particulate Mass ◽  
Incense Burning ◽  
Different Grain Size

Ash samples were collected using eight classifications of atmospheric particulate matter sampler in two temples located in Jiaozuo city. Concentration of particles of different grain size was measured and analyzed. The results indicated that particulate mass concentration was significantly increased in the burning incense air. The maximum concentration of PM9.0 and PM2.1 were 9 times than that of the national air quality secondary standard (PM9.0:0.15mg/m3) and 13.5 times for American standard (PM2.1:0.065mg/m3), respectively. The size distributions of particles from incense burning overall showed “U” model. Range of size distribution of fine particles concentrated in 1.1~0.43µm, or the total 39.36%~50.14%.

Fine Particulate Formation During Switchgrass/Coal Cofiring

2005 ◽  
Vol 127 (3) ◽  
pp. 457-463 ◽  
Author(s):  
Linda G. Blevins ◽  
Thomas H. Cauley
Keyword(s):  
Coal Combustion ◽  
Fine Particle ◽  
Mass Concentration ◽  
Particle Number ◽  
Fine Particles ◽  
Combustion Products ◽  
Scanning Mobility Particle Sizer ◽  
Fine Particulate ◽  
Particle Sizer ◽  
Mass Concentrations

Experiments to examine the effects of biomass/coal cofiring on fine particle formation were performed in the Sandia Multi-Fuel Combustor using fuels of pure coal, three combinations of switchgrass and coal, and pure switchgrass. For this work, fine particles with aerodynamic diameter between 10 nm and 1 μm were examined. A constant solid-fuel thermal input of 8 kW was maintained. The combustion products were cooled from 1200 to 420°C during passage through the 4.2 m long reactor to simulate the temperatures experienced in the convection pass of a boiler. Fine particle number densities, mass concentrations, and total integrated number and mass concentrations at the reactor exit were determined using a scanning mobility particle sizer. The fine particle number concentrations for cofiring were much higher than those achieved with dedicated coal combustion. However, the total integrated mass concentration of particles remained essentially constant for all levels of cofiring from 0% coal to 100% coal. The constant mass concentration is significant because pending environmental regulations are likely to be based on particle mass rather than particle size.

scholarly journals The Effect of Inlet Velocity on the Separation Performance of a Two-Stage Hydrocyclone

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 209 ◽  
Author(s):  
Lanyue Jiang ◽  
Peikun Liu ◽  
Yuekan Zhang ◽  
Xinghua Yang ◽  
Hui Wang
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Fine Particle ◽  
Fine Particles ◽  
Coarse Particle ◽  
Separation Performance ◽  
Two Stage ◽  
Inlet Velocity ◽  
Second Stage ◽  
Median Particle

The “entrainment of coarse particles in overflow” and the “entrainment of fine particlesin underflow” are two inevitable phenomena in the hydrocyclone separation process, which canresult in a wide product size distribution that does not meet the requirement of a preciseclassification. Hence, this study proposed a two-stage (TS) hydrocyclone, and the effects of the inletvelocity on the TS hydrocyclone were investigated using computational fluid dynamics (CFD).More specifically, the influences of the first-stage inlet velocity on the second-stage swirling flowfield and the separation performance were studied. In addition, the particle size distribution of theproduct was analyzed. It was found that the first-stage overflow contained few coarse particlesabove 40 μm and that the second-stage underflow contained few fine particles. The second-stageunderflow was free of particles smaller than 10 μm and almost free of particles smaller than 20 μm.The underflow product contained few fine particles. Moreover, the median particle size of thesecond-stage overflow product was similar to that of the feed. Inspired by this observation, wepropose to recycle the second-stage overflow to the feed for re-classification and to use only thefirst-stage overflow and the second-stage underflow as products. In this way, fine particle productsfree of coarse particle entrainment, and coarse particle products free of fine particle entrainmentcan be obtained, achieving the goal of precise classification.

scholarly journals Seasonal variations of ultra-fine and submicron aerosols in Taipei, Taiwan: implications for particle formation processes in a subtropical urban area

2016 ◽  
Vol 16 (3) ◽  
pp. 1317-1330 ◽  
Author(s):  
H. C. Cheung ◽  
C. C.-K. Chou ◽  
M.-J. Chen ◽  
W.-R. Huang ◽  
S.-H. Huang ◽  
...  
Keyword(s):  
Size Distribution ◽  
Urban Area ◽  
Seasonal Variations ◽  
Mass Concentration ◽  
Particle Number ◽  
Aerosol Particles ◽  
Particle Formation ◽  
Average Particle ◽  
Accumulation Mode ◽  
Photochemical Production

Abstract. The aim of this study is to investigate the seasonal variations in the physicochemical properties of atmospheric ultra-fine particles (UFPs, d ≤ 100 nm) and submicron particles (PM1, d ≤ 1 µm) in an east Asian urban area, which are hypothesized to be affected by the interchange of summer and winter monsoons. An observation experiment was conducted at TARO (Taipei Aerosol and Radiation Observatory), an urban aerosol station in Taipei, Taiwan, from October 2012 to August 2013. The measurements included the mass concentration and chemical composition of UFPs and PM1, as well as the particle number concentration (PNC) and the particle number size distribution (PSD) with size range of 4–736 nm. The results indicated that the mass concentration of PM1 was elevated during cold seasons with a peak level of 18.5 µg m−3 in spring, whereas the highest concentration of UFPs was measured in summertime with a mean of 1.64 µg m−3. Moreover, chemical analysis revealed that the UFPs and PM1 were characterized by distinct composition; UFPs were composed mostly of organics, whereas ammonium and sulfate were the major constituents of PM1. The seasonal median of total PNCs ranged from 13.9  ×  103 cm−3 in autumn to 19.4  ×  103 cm−3 in spring. Median concentrations for respective size distribution modes peaked in different seasons. The nucleation-mode PNC (N4 − 25) peaked at 11.6  ×  103 cm−3 in winter, whereas the Aitken-mode (N25 − 100) and accumulation-mode (N100 − 736) PNC exhibited summer maxima at 6.0  ×  103 and 3.1  ×  103 cm−3, respectively. The change in PSD during summertime was attributed to the enhancement in the photochemical production of condensable organic matter that, in turn, contributed to the growth of aerosol particles in the atmosphere. In addition, clear photochemical production of particles was observed, mostly in the summer season, which was characterized by average particle growth and formation rates of 4.0 ± 1.1 nm h−1 and 1.4 ± 0.8 cm−3 s−1, respectively. The prevalence of new particle formation (NPF) in summer was suggested as a result of seasonally enhanced photochemical oxidation of SO2 that contributed to the production of H2SO4, and a low level of PM10 (d ≤ 10 µm) that served as the condensation sink. Regarding the sources of aerosol particles, correlation analysis of the PNCs against NOx revealed that the local vehicular exhaust was the dominant contributor of the UFPs throughout the year. Conversely, the Asian pollution outbreaks had significant influence in the PNC of accumulation-mode particles during the seasons of winter monsoons. The results of this study implied the significance of secondary organic aerosols in the seasonal variations of UFPs and the influences of continental pollution outbreaks in the downwind areas of Asian outflows.

scholarly journals Profiling Dust Mass Concentration in Northwest China Using a Joint Lidar and Sun-photometer Setting

2021 ◽  
Vol 13 (6) ◽  
pp. 1099
Author(s):  
Tianhe Wang ◽  
Ying Han ◽  
Wenli Hua ◽  
Jingyi Tang ◽  
Jianping Huang ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Field Experiments ◽  
Negative Relationship ◽  
Northwest China ◽  
Dust Particles ◽  
Mass Loading ◽  
Average Mass ◽  
Dust Mass ◽  
Dust Loading ◽  
Sun Photometer

The satellite-based estimation of the dust mass concentration (DMC) is essential for accurately evaluating the global biogeochemical cycle of the dust aerosols. As for the uncertainties in estimating DMC caused by mixing dust and pollutants and assuming a fixed value for the mass extinction efficiency (MEE), a classic lidar-photometer method is employed to identify and separate the dust from pollutants, obtain the dust MEE, and evaluate the effect of the above uncertainties, during five dust field experiments in Northwest China. Our results show that this method is effective for continental aerosol mixtures consisting of dust and pollutants. It is also seen that the dust loading mainly occurred in the free troposphere (< 6 km), with the average mass loading of 905 ± 635 µg m−2 trapped in the planetary boundary layer. The dust MEE ranges from 0.30 to 0.60 m2 g−1 and has a significantly negative relationship with the size of dust particles. With the assumption of the dust MEE of 0.37 (0.60) m2 g−1, the DMC is shown to be overestimated (underestimated) by 20–40% (15–30%). In other words, our results suggest that the change of MEE with the size of dust particles should be considered in the estimation of DMC.

Application of Ceramic Membrane Technology in Tungsten Fine Particle Concentration Process

2014 ◽  
Vol 692 ◽  
pp. 191-199
Author(s):  
Wan Fu Huang ◽  
Xiao Feng Wang ◽  
Xin Dong Li ◽  
Si Ming Yan
Keyword(s):  
Fine Particle ◽  
Particle Concentration ◽  
Fine Particles ◽  
Ceramic Membrane ◽  
Membrane Technology ◽  
Factors Affecting ◽  
Membrane Flux ◽  
Concentration Test ◽  
Optimal Effect ◽  
Membrane Concentration

This study used ceramic membrane technology to concentrate tungsten fine particles for its inefficient recycling issue. Factors affecting the membrane concentration test were discussed, and the results show that: under the feed flow of 7000 mL/min, concentration time of 3 hours, and concentration liquid flow of 500 mL/min, it is the optimal effect of ceramic membrane concentration tungsten fine particle, which the interception rate reaches more than 99%, the membrane permeation flux can be nearly reach 470mL/(min×1099cm2) above, and concentrate concentration can be basically stable at around 29% . Ceramic membrane flux recovery rate can be as high as 93% by 7 minutes backwashing firstly and then 2 minutes forward cleaning.

scholarly journals Flow Characteristics and Grain Size Distribution of Granular Gangue Mineral by Compaction Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ran Yuan ◽  
Dan Ma ◽  
Hongwei Zhang
Keyword(s):  
Weight Loss ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Water Flow ◽  
Fine Particles ◽  
Flow Characteristics ◽  
Test System ◽  
Chemical Components ◽  
Gangue Mineral

A test system for water flow in granular gangue mineral was designed to study the flow characteristics by compaction treatment. With the increase of the compaction displacement, the porosity decreases and void in granular gangue becomes less. The main reason causing initial porosity decrease is that the void of larger size is filled with small particles. Permeability tends to decrease and non-Darcy flow factor increases under the compaction treatment. The change trend of flow characteristics shows twists and turns, which indicate that flow characteristics of granular gangue mineral are related to compaction level, grain size distribution, crushing, and fracture structure. During compaction, larger particles are crushed, which in turn causes the weight of smaller particles to increase, and water flow induces fine particles to migrate (weight loss); meanwhile, a sample with more weight of size (0–2.5 mm) has a higher amount of weight loss. Water seepage will cause the decrease of some chemical components, where SiO2 decreased the highest in these components; the components decreased are more likely locked at fragments rather than the defect of the minerals. The variation of the chemical components has an opposite trend when compared with permeability.

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