Numerical Simulation of Dust Deposition in the Filter Tube of Adsorption Air Purifier

In recent years, indoor air quality that deeply affected people’s health cannot be ignored. It is affected by many factors, and people have taken many measures to reduce the pollution level. In addition to diluting by controlling pollution sources and using natural ventilation, air purifiers have become one of the choices, but the results are not satisfactory. To improve the dust removal effect of the adsorption air purifier, we established the dynamic equation of PM2.5 concentration under different ventilation modes based on the analysis of indoor PM2.5 concentration change process, the integral and convergent operation of the equation were carried out, and the formula and main influencing factors of indoor PM2.5 concentration in steady state under different ventilation modes were obtained. Meanwhile, the mathematical model of the internal pipeline of the purifier was established by using the Navier-Stokes equation; we selected the DPM model in the software FLUENT to simulate the deposition of particulate matter in the ventilation pipe. The results showed that the deposition of different diameter particles in the filter tube was different. The movement of the larger particle size (particle diameter >10 μm) was mainly affected by the influence of gravity and inertia, while the fine particles are easily deposited on the inner wall side of the elbow mainly by the turbulent diffusion. Therefore, the angle of the elbow should be adjusted to direct the airflow so that most of the particulate matter could deposit on the filter element, reducing the particulate matter from the exhaust port and the damage to the human body in the room, which will improve the dedusting effect of the purifier.

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Interrelationship of Indoor particulate matter and Respiratory dust deposition of women in the residence of Dhanbad City, India

10.21203/rs.3.rs-446710/v1 ◽

2021 ◽

Author(s):

SHRAVAN KUMAR ◽

Manish Kumar Jain

Keyword(s):

Particulate Matter ◽

Health Risks ◽

Indoor Air ◽

Air Pollutants ◽

Fine Particles ◽

Dust Deposition ◽

Respiratory Problems ◽

Indoor Particulate Matter ◽

Indoor Air Pollutants ◽

Indoor Conditions

Abstract Women spend relatively more time in indoor conditions in developing countries. Exposure to various indoor air pollutants leads them to higher health risks according to Household air quality in which they reside. Particulate matter (PM) exposure with their exposure duration inside the household plays a significant role in women's Respiratory problems. We measured size segregated particulate matter concentrations in 63 residences at different locations. Respiratory dust depositions (RDDs) for 118 women in their different respiratory regions like head-airway (HD), tracheobronchial (TB), and alveolar (AL) region for the three PM size fractions (PM10, PM2.5 & PM1) were investigated. For different positions like Light exercise and the Sitting condition, RDD values found for AL region was 0.091 µgmin− 1 (SD: 0.067, 0.012–0.408) and 0.028 µgmin− 1 (SD: 0.021, 0.003–0.126) for PM10, 0.325 µgmin− 1 (SD: 0.254, 0.053–1.521) and 0.183 µgmin− 1 (SD: 0.143, 0.031–0.857) for PM2.5, 0.257 µgmin− 1 (SD: 0.197, 0.043–1.04) and 0.057 µgmin− 1 (SD: 0.044, 0.009–0.233) respectively for PM1 to females. RDDs values in the AL region significantly increases as PM10 (11%), PM2.5 (68%), and PM1 (21%), confirm that for women, the AL region is the most prominent affected zone by fine particles (PM2.5).

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On-site measurement and simulation of indoor particulate matter distributed in a single room with stratified flow field

Indoor and Built Environment ◽

10.1177/1420326x20919788 ◽

2020 ◽

pp. 1420326X2091978

Author(s):

Ho-Hsiang Lin ◽

Chung-Shin Yuan ◽

Wang-Kun Chen ◽

Chang-Tang Chang ◽

Pei-Shih Chen

Keyword(s):

Spatial Distribution ◽

Particulate Matter ◽

Natural Ventilation ◽

Fine Particles ◽

Model Simulation ◽

Stratified Flow ◽

Indoor Environments ◽

Single Room ◽

Room Model ◽

Indoor Particulate Matter

This study combined on-site measurement and model simulation to characterize the spatial distribution of indoor particulate matter (PM) in a single room with stratified flow fields. The concentration of PM spatially distributed in a single room with natural ventilation was measured at different heights for different PM sizes. This study revealed that the PM concentration varied with height and time. Moreover, chamber test results showed that by burning Chinese worship incense, fine particles (PM0–4) accounted for 97.33% of total PM with an average emission factor of 39.54 mg/g. The results were then applied to determine the gross emission of PM and describe its spatial distribution in a single room. Model simulation results indicated that only a small amount of PM flowed out of the room due to the trap by an indoor vortex under natural ventilation. The results are crucial for characterizing the stratified PM concentration and determining the sites for PM monitoring in indoor environments.

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A global association between Covid-19 cases and airborne particulate matter at regional level

Scientific Reports ◽

10.1038/s41598-021-85751-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Angelo Solimini ◽

F. Filipponi ◽

D. Alunni Fegatelli ◽

B. Caputo ◽

C. M. De Marco ◽

...

Keyword(s):

Air Pollution ◽

Particulate Matter ◽

Negative Binomial ◽

Numerical Models ◽

Regional Level ◽

Pollution Level ◽

Observation Data ◽

Cumulative Number ◽

Mixed Effect

AbstractEvidences of an association between air pollution and Covid-19 infections are mixed and inconclusive. We conducted an ecological analysis at regional scale of long-term exposure to air-borne particle matter and spread of Covid-19 cases during the first wave of epidemics. Global air pollution and climate data were calculated from satellite earth observation data assimilated into numerical models at 10 km resolution. Main outcome was defined as the cumulative number of cases of Covid-19 in the 14 days following the date when > 10 cumulative cases were reported. Negative binomial mixed effect models were applied to estimate the associations between the outcome and long-term exposure to air pollution at the regional level (PM10, PM2.5), after adjusting for relevant regional and country level covariates and spatial correlation. In total we collected 237,749 Covid-19 cases from 730 regions, 63 countries and 5 continents at May 30, 2020. A 10 μg/m3 increase of pollution level was associated with 8.1% (95% CI 5.4%, 10.5%) and 11.5% (95% CI 7.8%, 14.9%) increases in the number of cases in a 14 days window, for PM2.5 and PM10 respectively. We found an association between Covid-19 cases and air pollution suggestive of a possible causal link among particulate matter levels and incidence of COVID-19.

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Regulatory T Cells Protect Fine Particulate Matter-Induced Inflammatory Responses in Human Umbilical Vein Endothelial Cells

Mediators of Inflammation ◽

10.1155/2014/869148 ◽

2014 ◽

Vol 2014 ◽

pp. 1-14 ◽

Cited By ~ 6

Author(s):

Wen-cai Zhang ◽

Yan-ge Wang ◽

Zheng-feng Zhu ◽

Fang-qin Wu ◽

Yu-dong Peng ◽

...

Keyword(s):

T Cells ◽

Endothelial Cells ◽

Particulate Matter ◽

Inflammatory Cytokines ◽

Fine Particles ◽

Inflammatory Responses ◽

Umbilical Vein ◽

Fine Particulate Matter ◽

Fine Particulate ◽

Umbilical Vein Endothelial Cells

Objective. To investigate the role of CD4+CD25+T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms.Methods. Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm2) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4+CD25−T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined.Results. Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF-κB activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF-κB activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors.Conclusions. Tregs could attenuate fine particles-induced inflammatory responses and NF-κB activation in HUVECs.

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On the Accelerated Settling of Fine Particles in a Bidisperse Slurry

Mathematical Problems in Engineering ◽

10.1155/2015/169125 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Leonid L. Minkov ◽

Yuliya O. Stepanova ◽

Johann Dueck ◽

Elizaveta V. Pikushchak

Keyword(s):

Fine Particles ◽

Stokes Equations ◽

Fine Fraction ◽

Particle Diameter ◽

Sedimentation Velocity ◽

Navier Stokes ◽

Circulation Zone ◽

Navier Stokes Equations ◽

Volume Average ◽

Bidisperse Suspension

An estimation of increasing the volume average sedimentation velocity of fine particles in bidisperse suspension due to their capturing in the circulation zone formed in the laminar flow of incompressible viscous fluid around the spherical coarse particle is proposed. The estimation is important for an explanation of the nonmonotonic shape of the separation curve observed for hydrocyclones. The volume average sedimentation velocity is evaluated on the basis of a cellular model. The characteristic dimensions of the circulation zone are obtained on the basis of a numerical solution of Navier-Stokes equations. Furthermore, these calculations are used for modelling the fast sedimentation of fine particles during their cosedimentation in bidisperse suspension. It was found that the acceleration of sedimentation of fine particles is determined by the concentration of coarse particles in bidisperse suspension, and the sedimentation velocity of fine fraction is proportional to the square of the coarse and fine particle diameter ratio. The limitations of the proposed model are ascertained.

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A Verification and Validation Study of CFD Simulation of Wind-Induced Ventilation on Building with Single-Sided Opening

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.554.696 ◽

2014 ◽

Vol 554 ◽

pp. 696-700 ◽

Cited By ~ 2

Author(s):

Nur Farhana Mohamad Kasim ◽

Sheikh Ahmad Zaki ◽

Mohamed Sukri Mat Ali ◽

Ahmad Faiz Mohammad ◽

Azli Abd Razak

Keyword(s):

Open Source Software ◽

Natural Ventilation ◽

Cfd Simulation ◽

Previous Experiment ◽

Experimental Methods ◽

Verification And Validation ◽

Navier Stokes ◽

Navier Stokes Equation ◽

Computational Fluid Dynamics Cfd ◽

Model Approach

Wind-induced ventilation is widely acknowledged as one of the best approaches for inducing natural ventilation. Computational fluid dynamics (CFD) technique is gaining popularity among researchers as an alternative for experimental methods to investigate the behavior of wind-driven ventilation in building. In this present paper, Reynolds averaged Navier-Stokes equation (RANS) k-ε model approach is considered to simulate the airflow on a simplified cubic building with an opening on a single façade. Preliminary simulation using models from previous experiment indicates the reliability of OpenFOAM, the open source software that will be used in this study. The results obtained in this study will better define options for our future study which aims to explore how different buildings arrays modify the airflow inside and around a naturally ventilated building.

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Ambient Particulate Matter Air Pollution in Mpererwe District, Kampala, Uganda: A Pilot Study

Journal of Environmental and Public Health ◽

10.1155/2014/763934 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 11

Author(s):

Stephan Schwander ◽

Clement D. Okello ◽

Juergen Freers ◽

Judith C. Chow ◽

John G. Watson ◽

...

Keyword(s):

Particulate Matter ◽

Air Quality ◽

Pilot Study ◽

Fine Particles ◽

Airborne Particulate Matter ◽

Personal Exposure ◽

Ambient Air ◽

Combustion Products ◽

Carbonaceous Aerosol ◽

Coarse Particles

Air quality in Kampala, the capital of Uganda, has deteriorated significantly in the past two decades. We made spot measurements in Mpererwe district for airborne particulate matter PM2.5(fine particles) and coarse particles. PM was collected on Teflon-membrane filters and analyzed for mass, 51 elements, 3 anions, and 5 cations. Both fine and coarse particle concentrations were above 100 µg/m3in all the samples collected. Markers for crustal/soil (e.g., Si and Al) were the most abundant in the PM2.5fraction, followed by primary combustion products from biomass burning and incinerator emissions (e.g., K and Cl). Over 90% of the measured PM2.5mass can be explained by crustal species (41% and 59%) and carbonaceous aerosol (33%–55%). Crustal elements dominated the coarse particles collected from Kampala. The results of this pilot study are indicative of unhealthy air and suggest that exposure to ambient air in Kampala may increase the burden of environmentally induced cardiovascular, metabolic, and respiratory diseases including infections. Greater awareness and more extensive research are required to confirm our findings, to identify personal exposure and pollution sources, and to develop air quality management plans and policies to protect public health.

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Imperiling on Urban Environment by Air Pollution and its Impact on Human Health

Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences ◽

10.52763/pjsir.phys.sci.62.2.2019.104.112 ◽

2019 ◽

Vol 62 (2) ◽

pp. 104-112

Author(s):

Durdana Rais Hashmi ◽

Akhtar Shareef ◽

Talha Rehan Qadri ◽

Muhammad Azam

Keyword(s):

Particulate Matter ◽

Human Health ◽

Trace Gases ◽

Quality Standard ◽

Traffic Density ◽

Pollution Level ◽

Residential Areas ◽

Industrial Emissions ◽

Industrial Areas ◽

High Traffic Density

Present study was carried out to analyze the concentration of the pollutants due to air born particulate matter (PM10) and infectious trace gases and their effects on human health at ten different locations along busy intersections in the commercial, residential and industrial areas of Karachi city. At each selected location, the study was carried out to determine the level of particulate matter and trace gases for a period of 8 h twice in a month during the year 2015. Samples were collected at ten selected locations i.e. Karimabad(C-1), Tibet Centre(C-2), and Liaquatabad(C-3) in commercial areas; PIB Colony(R-1), Nazimabad(R-2) and Gulshan-e-Iqbal(R-3) in residential areas; Siemens G. Belt(I-E1), Naurus G Belt (I-E2), Singer Chowrangi(I-W3) and Chamra Chowrangi(I-W4) in industrial areas of the city. Resultsreceived from different air quality categories were calculated according to National Environmental Quality Standard (NEQS) at selected locations, as in commercial areas showing poor pollution level for trace gases and PM10 due to high traffic density. In Residential areas PIB Colony (R-1) and Gulshan-e-Iqbal (R-3), found under good category with respect to the trace gases and moderate pollution level for the PM10 pollution, having low traffic density whereas Nazimabad(R-2) presents moderate category for trace gases and unhealthy category for PM10 pollution with high traffic density. In industrial areas Singer Chowrangi (I-W3) and Chamra Chowrangi(I-W4) found under moderate pollution level with moderate traffic density, whereas, Siemens G. Belt(I-E1) and Naurus G. Belt(I-E2) locations are represented by moderate pollution values for trace gases and found under poor pollution level for PM10 pollution, may be due to industrial emissions and heavy vehicular emission. Level of PM10 and trace gases at all the selected sites excluding residential areas, exceeds the permissible limits as specified by NEQS.

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Effect of Air Purifier Use in the Classrooms on Indoor Air Quality—Case Study

Atmosphere ◽

10.3390/atmos12121606 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1606

Author(s):

Małgorzata Basińska ◽

Michał Michałkiewicz ◽

Katarzyna Ratajczak

Keyword(s):

Particulate Matter ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Air Purification ◽

Portable Devices ◽

Microscopic Fungi ◽

Before And After ◽

Air Purifier ◽

High Level

Dissatisfaction with indoor air quality is common even in relatively new or renovated Polish school buildings. To improve air quality in educational buildings, portable devices have seen increased use, for which manufacturers guarantee a high level of indoor air purification. However, their optimized operation largely depends on their correct use. The aim of this article was to determine the effectiveness of air purification in a primary school using an air purification device with an analysis of the classroom indoor air quality (IAQ). Two criteria were used, microbiological and particulate matter concentration. Measurements were made before device installation and during its continuous operation, and before and after lessons on chosen days. Measurements related to IAQ did not detect clear differences in the analyzed measurement periods. For microbiological contamination, in the morning before lessons, the total count for all bacteria and microscopic fungi was definitely lower than after lessons. Comparing the periods before and after device installation, no clear tendency for reducing the bacteria count or microscopic fungi occurred during air purifier operation, nor was there any noticeable trend in the reduction of particulate matter. There was no improvement in air quality in the classrooms during the operation of the purification devices.

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Occupational Exposure to Fine Particulate Matter (PM4 and PM2.5) during Hand-Made Cookware Operation: Personal, Indoor and Outdoor Levels

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17207522 ◽

2020 ◽

Vol 17 (20) ◽

pp. 7522

Author(s):

Busisiwe Shezi ◽

Angela Mathee ◽

Nokulunga Cele ◽

Sipho Ndabandaba ◽

Renee A. Street

Keyword(s):

Particulate Matter ◽

Occupational Exposure ◽

Fine Particles ◽

Fine Particulate Matter ◽

Health And Safety ◽

Chemical Characterization ◽

Personal Exposure ◽

Targeted Prevention ◽

Fine Particulate ◽

Indoor And Outdoor

(1) Exposure of informal artisanal cookware makers to fine particles has not yet been characterized. The aim of this study was to characterize occupational exposure to fine particulate matter (PM4 and PM2.5) levels and fine particulate matter (PM2.5) elemental components; (2) Artisanal cookware makers were recruited from five cookware making sites. Exposure to fine particulate matter was measured for 17 male participants. SidePak personal aerosol monitors (AM520) were used to measure personal exposure to PM4, while a DustTrak monitor and an E-sampler were used to assess indoor and outdoor PM2.5 levels, respectively. A questionnaire was administered to capture information on demographic characteristics. The chemical characterization of indoor and outdoor PM2.5 filter mass was conducted using Wavelength Dispersive X-ray Fluorescence. Time series record of 15-min averages for indoor and outdoor PM2.5 levels were assessed; (3) The median (range) was 124 µg/m3 (23−100,000), 64 µg/m3 (1−6097) and 12 µg/m3 (4−1178), respectively, for personal PM4, indoor and outdoor PM2.5. The highest levels for many of the elemental components of PM2.5 were found in the outdoor PM2.5 filter mass and (4). The information generated during this study may assist in extending occupational health and safety strategies to artisanal cookware makers and developing targeted prevention initiatives.

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