Size distribution and sources of humic-like substances in particulate matter at an urban site during winter

2016 ◽  
Vol 18 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Seungshik Park ◽  
Se-Chang Son
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Distribution ◽  
Bimodal Distribution ◽  
Asian Dust ◽  
Urban Site

The highest contribution of HULIS-C to WSOC was observed to be in the particle size bins of 0.55–1.0 μm and 1.8–3.1 μm during non-Asian dust (NAD, 45 ± 6%) and Asian dust (AD, 44 ± 7%) periods, respectively. HULIS exhibited a uni-modal (@0.55 μm) distribution during the NAD and a bimodal distribution (@0.32 and 1.8 μm) during AD, respectively.

scholarly journals Size distribution of particle-associated polybrominated diphenyl ethers (PBDEs) and their implications for health

2016 ◽  
Vol 9 (3) ◽  
pp. 1025-1037 ◽  
Author(s):  
Yan Lyu ◽  
Tingting Xu ◽  
Xiang Li ◽  
Tiantao Cheng ◽  
Xin Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Polybrominated Diphenyl Ethers ◽  
Fine Particles ◽  
Bimodal Distribution ◽  
Urban Site ◽  
Deposition Flux ◽  
Human Respiratory Tract ◽  
Particle Size Range ◽  
Peak Intensity

Abstract. In order to better understand the size distribution of particle-associated PBDEs and their deposition pattern in the human respiratory tract, we carried out a 1-year campaign during 2012–2013 for the measurement of size-resolved particles at the urban site of Shanghai. The results showed that particulate PBDEs exhibited a bimodal distribution with a mode peak in the accumulation particle size range and the second mode peak in the coarse particle size ranges. As the number of bromine atoms in the molecule increases, accumulation-mode peak intensity increased while coarse-mode peak intensity decreased. This change was consistent with the variation of PBDEs' subcooled vapor pressure. Absorption and adsorption processes dominated the distribution of PBDEs among the different size particles. The evaluated deposition flux of Σ13 PBDEs was 26.8 pg h−1, in which coarse particles contributed most PBDEs in head and tracheobronchial regions, while fine-mode particles contributed major PBDEs in the alveoli region. In association with the fact that fine particles can penetrate deeper into the respiratory system, fine-particle-bound highly brominated PBDEs can be inhaled more deeply into human lungs and cause a greater risk to human health.

Characterization of the emission behavior of pulse-jet cleaned filters using a low-cost particulate matter sensor/Charakterisierung der Emission von druckstoßgereinigten Oberflächenfiltern mit einem Low-Cost-Feinstaubsensor

Gefahrstoffe ◽  
2019 ◽  
Vol 79 (11-12) ◽  
pp. 443-450
Author(s):  
P. Bächler ◽  
J. Meyer ◽  
A. Dittler
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Low Cost ◽  
Particle Emission ◽  
Filter Medium ◽  
Emission Measurement ◽  
Pm2.5 Concentration ◽  
Pulse Jet

The reduction of fine dust emissions with pulse-jet cleaned filters plays an important role in industrial gas cleaning to meet emission standards and protect the environment. The dust emission of technical facilities is typically measured “end of pipe”, so that no information about the local emission contribution of individual filter elements exists. Cheap and compact low-cost sensors for the detection of particulate matter (PM) concentrations, which have been prominently applied for immission monitoring in recent years have the potential for emission measurement of filters to improve process monitoring. This publication discusses the suitability of a low-cost PM-sensor, the model SPS30 from the manufacturer Sensirion, in terms of the potential for particle emission measurement of surface filters in a filter test rig based on DIN ISO 11057. A Promo® 2000 in combination with a Welas® 2100 sensor serves as the optical reference device for the evaluation of the detected PM2.5 concentration and particle size distribution of the emission measured by the low-cost sensor. The Sensirion sensor shows qualitatively similar results of the detected PM2.5 emission as the low-cost sensor SDS011 from the manufacturer Nova Fitness, which was investigated by Schwarz et al. in a former study. The typical emission peak after jet-pulse cleaning of the filter, due to the penetration of particles through the filter medium, is detected during Δp-controlled operation. The particle size distribution calculated from the size resolved number concentrations of the low-cost sensor yields a distinct distribution for three different employed filter media and qualitatively fits the size distribution detected by the Palas® reference. The emission of these three different types of filter media can be distinguished clearly by the measured PM2.5 concentration and the emitted mass per cycle and filter area, demonstrating the potential for PM emission monitoring by the low-cost PM-sensor. During the period of Δt-controlled filter aging, a decreasing emission, caused by an increasing amount of stored particles in the filter medium, is detected. Due to the reduced particle emission after filter aging, the specified maximum concentration of the low-cost sensor is not exceeded so that coincidence is unlikely to affect the measurement results of the sensor for all but the very first stage of filter life.

scholarly journals Particle Size Distribution of E-Cigarette Aerosols and the Relationship to Cambridge Filter Pad Collection Efficiency

2015 ◽  
Vol 26 (4) ◽  
Author(s):  
Steven L. Alderman ◽  
Chen Song ◽  
Serban C. Moldoveanu ◽  
Stephen K. Cole
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Propylene Glycol ◽  
Collection Efficiency ◽  
Transmission Measurement ◽  
Average Particle ◽  
Electrical Mobility ◽  
Total Particulate Matter

AbstractThe relatively volatile nature of the particulate matter fraction of e-cigarette aerosols presents an experimental challenge with regard to particle size distribution measure-ments. This is particularly true for instruments requiring a high degree of aerosol dilution. This was illustrated in a previous study, where average particle diameters in the 10-50 nm range were determined by a high-dilution, electrical mobility method. Total particulate matter (TPM) masses calculated based on those diameters were orders of magnitude smaller than gravimetrically determined TPM. This discrepancy was believed to result from almost complete particle evaporation at the dilution levels of the electrical mobility analysis. The same study described a spectral transmission measurement of e-cigarette particle size in an undiluted state, and reported particles from 210-380 nm count median diameter. Observed particle number concentrations were in the 10Described here is a study in which e-cigarette aerosols were collected on Cambridge filters with adsorbent traps placed downstream in an effort to capture any material passing through the filter. Amounts of glycerin, propylene glycol, nicotine, and water were quantified on the filter and downstream trap. Glycerin, propylene glycol, and nicotine were effciently captured (> 98%) by the upstream Cambridge filter, and a correlation was observed between filtration efficiency and the partial vapor pressure of each component. The present analysis was largely inconclusive with regard to filter efficiency and particle-vapor partitioning of water. [Beitr. Tabakforsch. Int. 26 (2014) 183-190]

scholarly journals Monte Carlo simulation for soot dynamics

2012 ◽  
Vol 16 (5) ◽  
pp. 1391-1394 ◽  
Author(s):  
Kun Zhou
Keyword(s):  
Particle Size ◽  
Monte Carlo ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Gas Phase ◽  
Volume Fraction ◽  
Soot Formation ◽  
Bimodal Distribution ◽  
Number Density ◽  
Stochastic Error

A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well with the measurement available in literature. The origin of the bimodal distribution of particle size distribution is revealed with quantitative proof.

scholarly journals Spatial and Seasonal Variations of PM Concentration and Size Distribution in Manure-Belt Poultry Layer Houses

2019 ◽  
Vol 62 (2) ◽  
pp. 415-427 ◽  
Author(s):  
Reyna M. Knight ◽  
Xinjie Tong ◽  
Zhenyu Liu ◽  
Sewoon Hong ◽  
Lingying Zhao
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Distribution ◽  
Seasonal Variations ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Potential Health ◽  
Significant Difference ◽  
Autumn And Winter ◽  
Mass Concentrations

Abstract. Poultry layer houses are a significant source of particulate matter (PM) emissions, which potentially affect worker and animal health. Particulate matter characteristics, such as concentration and size distribution inside layer houses, are critical information for assessment of the potential health risks and development of effective PM mitigation technologies. However, this information and its spatial and seasonal variations are lacking for typical layer facilities. In this study, two TSI DustTrak monitors (DRX 8533) and an Aerodynamic Particle Sizer (APS 3321) were used to measure PM mass concentrations and number-weighted particle size distributions in two typical manure-belt poultry layer houses in Ohio in three seasons: summer, autumn, and winter. Bimodal particle size distributions were consistently observed. The average count median diameters (mean ±SD) were 1.68 ±0.25, 2.16 ±0.31, and 1.87 ±0.07 µm in summer, autumn, and winter, respectively. The average geometric standard deviations of particle size were 2.16 ±0.23, 2.16 ±0.18, and 1.74 ±0.17 in the three seasons, respectively. The average mass concentrations were 67.4 ±54.9, 289.9 ±216.2, and 428.1 ±269.9 µg m-3 for PM2.5; 73.6 ±59.5, 314.6 ±228.9, and 480.8 ±306.5 µg m-3 for PM4; and 118.8 ±99.6, 532.5 ±353.0, and 686.2 ±417.7 µg m-3 for PM10 in the three seasons, respectively. Both statistically significant (p < 0.05) and practically significant (difference of means >20% of smaller value) seasonal variations were observed. Spatial variations were only practically significant for autumn mass concentrations, likely due to external dust infiltration from nearby agricultural activities. The OSHA-mandated permissible exposure limit for respirable PM was not exceeded in any season. Keywords: Air quality, Particulate matter, Poultry housing, Seasonal variation, Spatial variation.

A Noise Removal Method in Measurement of Particle Size Distribution by the Shifrin-Transform

2014 ◽  
Vol 1058 ◽  
pp. 93-96 ◽  
Author(s):  
Yue Han ◽  
Zong Ling Yang ◽  
Yin Nan Yuan ◽  
Bing Dai
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Large Angle ◽  
Bimodal Distribution ◽  
Noise Removal ◽  
Good Effect ◽  
Actual Measurement ◽  
Original Distribution ◽  
Angle Data

In actual measurement of particle size distribution by the Shifrin-transform, many noises are easily misread as distribution peaks, and bring serious difficulties to the measurement. The purpose of this paper is to find a method of removing these noises to improve existing technology. By analyzing the source of these noises, we found these noises are mainly caused by the serious large angle data loss, and then propose a compensation function in the Shifrin-transform to remove these noises. Simulations explain that the method has a good effect. The method is actually tested for the sample particles of the unimodal and bimodal distribution by experiments. The result shows that the noises disappear but the number and location of original distribution peaks aren’t affected after using the compensate function. So this method can remove effectively noises and restore accurately original distribution in the measurement.

Effects of Particle Size and Size Distribution on the Mechanical Properties of EPDM/Silica Vulcanizates

2008 ◽  
Vol 47-50 ◽  
pp. 113-116 ◽  
Author(s):  
M.N. Ichazo ◽  
C. Albano ◽  
M. Hernández ◽  
J. González ◽  
A. Carta
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Size Distribution ◽  
Surface Area ◽  
Bimodal Distribution ◽  
Epdm Rubber ◽  
Surface Areas ◽  
Precipitated Silica ◽  
Internal Mixer ◽  
Tear Properties

In this work we present the influence of different particle size (surface areas: 120,150, 200 and 250 m2/g) and size distribution of precipitated silica on the mechanical properties of Ethylene- Propylene-Diene (EPDM) rubber. The vulcanization system employed was efficient. Compounds were prepared using a Banbury internal mixer. Tensile and tear properties of vulcanized blends were determined according to ASTM D412 and ASTM D624 procedures, respectively. Results show an increasing tendency on tensile properties when particle size decreases, due to the better dispersion of the filler and to a greater interaction with the rubber. Increases of up to 500% on tensile strength and 400% on tear strength were observed. However, there was an incoherent behavior for the silica with surface area of 200 m2/g (Si-200), so size distribution of the aggregates was experimentally determined by a microphotography study. Secondary aggregates size distribution was very different for each type of silica. Aggregates for Si-200 presented a bimodal distribution where the greater frequencies correspond to aggregates with surface area higher than the corresponding values for the Si-120. This fact could explain why the mechanical properties of the EPDM filled with Si-200 are not in between the values of the compounds filled with Si-150 and Si-250.

scholarly journals Developing a Relative Humidity Correction for Low-Cost Sensors Measuring Ambient Particulate Matter

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2790 ◽  
Author(s):  
Andrea Di Antonio ◽  
Olalekan Popoola ◽  
Bin Ouyang ◽  
John Saffell ◽  
Roderic Jones
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Relative Humidity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Low Cost ◽  
Monitoring Networks ◽  
Ambient Particulate Matter ◽  
Correction Algorithm ◽  
Ambient Conditions

There is increasing concern about the health impacts of ambient Particulate Matter (PM) exposure. Traditional monitoring networks, because of their sparseness, cannot provide sufficient spatial-temporal measurements characteristic of ambient PM. Recent studies have shown portable low-cost devices (e.g., optical particle counters, OPCs) can help address this issue; however, their application under ambient conditions can be affected by high relative humidity (RH) conditions. Here, we show how, by exploiting the measured particle size distribution information rather than PM as has been suggested elsewhere, a correction can be derived which not only significantly improves sensor performance but which also retains fundamental information on particle composition. A particle size distribution–based correction algorithm, founded on κ -Köhler theory, was developed to account for the influence of RH on sensor measurements. The application of the correction algorithm, which assumed physically reasonable κ values, resulted in a significant improvement, with the overestimation of PM measurements reduced from a factor of ~5 before correction to 1.05 after correction. We conclude that a correction based on particle size distribution, rather than PM mass, is required to properly account for RH effects and enable low cost optical PM sensors to provide reliable ambient PM measurements.

Nearfield development of the negatively buoyant Rhône River inflow into Lake Geneva as an interflow: suspended particulate matter and associated fluxes.

2021 ◽  
Author(s):  
Violaine Piton ◽  
Frédéric Soulignac ◽  
Ulrich Lemmin ◽  
Graf Benjamin ◽  
Htet Kyi Wynn ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Suspended Particulate Matter ◽  
Fine Particles ◽  
River Plume ◽  
Lake Geneva ◽  
Suspended Particulate ◽  
Negatively Buoyant

<p>River inflows have a major influence on lake water quality through their input of sediments, nutrients and contaminants. It is therefore essential to determine their pathways, their mixing with ambient waters and the amount and type of Suspended Particulate Matter (SPM) they carry. Two field campaigns during the stratified period took place in Lake Geneva, Switzerland, in the vicinity of the Rhône River plume, at high and intermediate river discharge. Currents, water and sediment fluxes, temperature, turbidity and particle size distribution were measured along three circular transects located at 400, 800 and 1500 m in front of the river mouth. During the surveys, the lake was thermally stratified, the negatively buoyant Rhône River plume plunged and intruded into the metalimnion as an interflow and flowed out in the streamwise direction. Along the pathway, interflow core velocities, SPM concentrations and volumes of particles progressively decreased with the distance from the mouth (by 2-3 times), while interflow cross sections and plume volume increased by 2-3 times due to entrainment of ambient water. The characteristics of the river outflow determined the characteristics of the interflows: i.e. interflow fluxes and concentrations were the highest at high discharge. Both sediment settling and interflow dilution contributed to the observed decrease of sediment discharge with distance from the mouth. The particle size distribution of the interflow was dominated by fine particles (<32 μm), which were transported up to 1500 m away from the mouth and most likely beyond, while large particles (>62 μm) have almost completely settled out before reaching 1500 m. </p>

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