Dispersion Of Particulate Matter Research Articles

Spatiotemporal Dispersal and Deposition of Fish Farm Wastes: A Model Study from Central Norway

Abstract A spatially explicit coupled hydrodynamic-mass transport model system was used to simulate dispersal of particulate organic matter from Atlantic salmon (Salmo salar) farming in central Norway. Model setups of 32 m horizontal resolution were run for periods of up to 650 days for 3 sites of different oceanographic characteristics: one fjord location, one medium-exposed location influenced by fjord water and one coastal location. Records on feed used for each cage at each location were converted to feces released based on a published mass balance model. The results from the simulations were compared with scores from corresponding mandatory benthic surveys (MOM-B) of the sediment layer beneath the farms. The correspondence between simulated and measured thickness of the sediment layer was good, and improved with the inclusion of resuspension processes. At all sites the distribution of organic matter in the bottom layer was non-homogeneous, with significant temporal variation and transport and settling of matter up to at least 0.5 km away from one of the farms. Our results indicate that the monitoring practice used in Norway until now, with a few sediment grab samples taken mainly within the fish farm, may not adequately determine the areal impacts of all salmon farming operations. The patchy distribution of organic matter and the correspondence between simulation and survey results is attributed to the use of full 3D current fields of a high spatiotemporal resolution and a good model for resuspension processes that some previous model studies have failed to properly account for.

Assessment of role of concrete factories in particulate matter emissions, 2015-2016, using the AQI index and zoning by GIS software (Case study: Nasr Kashan Concrete Factory)

Background: Reducing the effects of climate change and air pollution is a global priority at present. To formulate effective policies for achieving such a reduction requires a good understanding of the underlying phenomena. This study assessed the role of Nasr Kashan Factory in the emissions of particulate matter (PM). Methods: In this cross-sectional study, PM concentrations at 9 stations inside and around the Nasr Kashan Concrete Factory were determined at the unit’s active and inactive times. The air quality index (AQI) was obtained and data was entered into ArcGIS 10.2 to obtain a zoning map of PM dispersion. Results: The results showed that all AQI peaks were within the very healthy or the healthy range at the Factory’s inactive times. When the factory was working, the AQIs ranged from 24.1 to 634 μg/m3, which falls into the good and very hazardous categories. These results were dependent upon distance from the factory and were further affected by other produced factors of PM10. Conclusion: The results of this paper showed that average PM emissions at the Nasr Kashan Concrete Factory were much lower during inactive times than during times of activity. Therefore, the Nasr Kashan Concrete Factory plays an important role in the emission of PM and in air pollution in the studied area. PM concentrations were higher near and inside the studied factory, and the AQI was in the hazardous category.

Investigation of the Potential and Mechanism of Clove for Mitigating Airborne Particulate Matter Emission from Stationary Sources

Vegetative Barriers (VB) have the potential to mitigate air pollutants emitted from area sources, including concentrated Animal Feeding Operations (AFOs). However, the mechanism has not been fully investigated, thereby limiting the application of vegetation systems in practice. An experimental method with repeatable and controllable conditions was developed to measure the change of Particulate Matter (PM) concentrations at upwind and downwind of VB in the wind tunnel and observe accumulated PM on leaves with Scanning Electron Microscope (SEM), thus evaluating the ability of VB in mitigating PM emitted from AFOs. Branch-scale vegetation, clove (syzygium aromaticum) was selected because its leaves are one of the major factors affecting PM dispersion. The results show that the branch-scale barriers, as porous medium have the ability to interfere with airflow and reduce PM, which could be influenced by wind speed, particle size fraction and surface area density of clove. Moreover, clove elements could adjust to the wind and the micro structure of clove (such as the hierarchical structures of leaves) affected on the PM deposition. These results indicate that the methods developed in this study may be used to evaluate the potential of vegetation in mitigating PM from stationary sources, and some characteristics of vegetation can be further studied as bionic prototype for exploring engineering application of reducing particulates.

Trajectory and Concentration PM10 on Forest and Vegetation Peat-Fire HYSPLIT Model Outputs and Observations (Period: September – October 2015)

Forest and vegetation peat-fire is one of the main sources of air pollution in Kalimantan, predominantly during the dry period. In 2015, forest and vegetation fire in Central Kalimantan and South Kalimantan emit large quantities of smoke leading to poor air quality. Haze is a phenomenon characterized by high concentration of particulate matter. This research objective is to analyze trajectory and dispersion of concentration particulate matter, PM10 in Banjarbaru and Palangka Raya. Dynamics of PM10 (Particulate matter less than or 10 µm in size) on vegetation peat-fire is done using GDAS (Global Data Assimilation System) output with a horizontal resolution 1º which corresponds to 100 km × 100 km for input model. Climate conditions in the period September to October 2015 at generally during dry season of El Nino year. The Hybrid-single Langrangian Integrated Trajectory (HYSPLIT) model was used to investigate concentration and long-range movement of this pollutant from the source to the receptor area. We used time-series data on PM10 readings obtained from two stations Banjarbaru (South Kalimantan) and Palangka Raya (Central Kalimantan) belonging to Meteorology Climatology and Geophysics Agency (BMKG). We also used weather parameter such as wind speed and direction. We investigated trajectory run from hotspots information MoF (Sipongi Output Programs) and HYSPLIT. We compared concentration obtained from PM10 observation and its concentrations trend. The dispersion pattern, as simulated by HYSPLIT showed that the distribution of PM10 was greatly influenced by the wind direction and topography. There is a large difference between the concentration of PM10 Palangka Raya and Banjarbaru.

Corrigendum to “Simulation of particulate matter ingress, dispersion and deposition in a historical building” [J. Cult. Herit. 18 (2016) 199–208

Corrigendum to “Simulation of particulate matter ingress, dispersion and deposition in a historical building” [J. Cult. Herit. 18 (2016) 199–208

Research into the impact of speed bumps on particulate matter air pollution

Abstract Most traffic accidents occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris or other stationary obstruction, such as a tree or utility pole. One of the most popular speed regulation implement is speed bumps. Speed bumps are installed in residential areas and towns to regulate the speed of traffic. When vehicles pass through them air pollution with particulate matter increases due to emissions from vehicles during braking and particulate matter dispersion. Transport is one of the particulate matter emission sources of the size of 10 μm (PM10) and less that are harmful to humans and nature in general, have been studied. Air pollution with particulate matter at speed bumps was assessed analysing speed bumps structures of different types installed in Lithuania's different residential areas. According to the research it was found particulate pollution at different car number and relative humidity. As determined according to the results of the performed research, air pollution with particulate matter increases by 2–5 times. Pollution near the trapezium-shaped pedestrian crossings increased 55.7% and near the plastic circular speed bumps – 58.6%.

PM10 Dispersion Modeling by Means of CFD 3D and Eulerian–Lagrangian Models: Analysis and Comparison with Experiments

This research deals with the analysis of the dispersion of PM10 by using fluid-dynamic simulation framework. Firstly, an experimental campaign was made in a wind tunnel. A cylindrical emitter of PM10 was characterized in terms of PM10 mass flow rate and outlet velocity. It was positioned in the wind tunnel chamber where several sensors were also placed downwind. The use of different sensor configurations allowed the evaluation of the PM10 concentrations in several locations. The experimental campaign was reproduced in ANSYS-Fluent, by recreating in Design-Model, a 3D geometries of the test case. Different calculation grids were tested in order to find the proper balance between computing time and accuracy. The CFD 3D model was based on the Eulerian approach for the continuous phase and Lagrangian approach for the dispersion phase setting the DPM for the evaluation and dispersion of particulate matters. The turbulence was solved by using a k-ɛ RANS approach and a quite advanced unsteady DES model. Several simulations were carried out by varying the flow inlet velocities in configurations with and without obstacles. The results obtained from the post-processing phase were then compared with the experimental campaign. With obstacles a PM concentration increment is observed at all imposed air velocity because of recirculation phenomena generated around the obstacles.

Particulate matter pollution in opencast coal mining areas: a threat to human health and environment

With the increase in depth of mines, the movement and dispersion of particulate matter (PM) are very difficult to predict due to improper ventilation. Insufficient open pit ventilation remains the principal driver for the lack of dispersion and evacuation from mines and ultimately increases the time and amount of exposure to miners. Studies suggest that there is a direct and dependent relationship between the composition and exposure time to PM in mining operations. Furthermore, this paper helps the reader appreciate the need of carrying out studies to understand the nature of the dispersion of PM inside the mines.

Modelling and mapping trace element accumulation in Sphagnum peatlands at the European scale using a geomatic model of pollutant emissions dispersion

Trace elements (TEs) transported by atmospheric fluxes can negatively impact isolated ecosystems. Modelling based on moss-borne TE accumulation makes tracking TE deposition in remote areas without monitoring stations possible. Using a single moss species from ombrotrophic hummock peatlands reinforces estimate quality. This study used a validated geomatic model of particulate matter dispersion to identify the origin of Cd, Zn, Pb and Cu accumulated in Sphagnum capillifolium and the distance transported from their emission sources. The residential and industrial sectors of particulate matter emissions showed the highest correlations with the TEs accumulated in S. capillifolium (0.28(Zn)-0.56(Cu)) and (0.27(Zn)-0.47(Cu), respectively). Distances of dispersion varied depending on the sector of emissions and the considered TE. The greatest transportation distances for mean emissions values were found in the industrial (10.6 km when correlating with all TEs) and roads sectors (13 km when correlating with Pb). The residential sector showed the shortest distances (3.6 km when correlating with Cu, Cd, and Zn). The model presented here is a new tool for evaluating the efficacy of air pollution abatement policies in non-monitored areas and provides high-resolution (200 × 200 m) maps of TE accumulation that make it possible to survey the potential impacts of TEs on isolated ecosystems.

Quantifying the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building

Improper natural ventilation practices may deteriorate indoor air quality when in close proximity to roadways, although the intention is often to reduce energy consumption. In this study, we employed a CFD-based air quality model to quantify the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building. Our study found that the building envelope restricts dispersion and dilution of particulate matter. The indoor concentration in the baseline condition located 10m away from the roadway is roughly 16–21% greater than that at the edge of the roadway. The indoor flow recirculation creates a well-mixed zone with little variation in fine particle concentration (i.e., 253nm). For ultrafine particles (<100nm), a noticeable decrease in particle concentrations indoors with increasing distance from the road is observed due to Brownian and turbulent diffusion. In addition, the indoor concentration strongly depends on the distance between the roadway and building, particle size, wind condition, and window size and location. A break-even point is observed at D′~2.1 (normalized distance from the roadway by the width of the road). The indoor particle concentration is greater than that at the highway where D′<2.1, and vice versa. For new building planning, the distance from the roadway and the ambient wind condition need to be considered at the early design stage whereas the size and location of the window openings, the interior layout, and the placement of fresh air intakes are important to the indoor air quality of existing buildings adjacent to roadways.

Modeling of particulate matter transport in atmospheric boundary layer following dust emission from source areas

Abstract A two-dimensional model for particulate matter (PM) dispersion due to dust emission from soils is presented. Field experiments were performed at a dust source site (Negev loess soil) with a portable boundary layer wind tunnel to determine the emitted PM fluxes for different wind speeds and varying soil conditions. The numerical model is formulated using parameterizations based on the aeolian experiments. The wind velocity profiles used in the simulations were fitted from data obtained in field measurements. Size distribution of the emitted dust particles in the numerical simulations was taken into account using a Monte Carlo method. The PM concentration distributions at a distance of several kilometers from the dust source under specific shear velocities and PM fluxes from the soil were determined numerically by solving advection–diffusion equation. The obtained PM 10 concentrations under typical wind and soil conditions are supported by PM data recorded over time in a standard environmental monitoring station. The model enhances our capacity of quantification of dust processes to support climate models as well as health risk assessment.

A diesel particulate matter dispersion study inside a single dead end entry using dynamic mesh model

Three-dimensional simulations of diesel particulate matter (DPM) distribution inside a single dead end entry with a push-pull system for the load-haul-dump (LHD)-truck loading and truck hauling operations were carried out using ANSYS FLUENT computational fluid dynamics (CFD) software. The loading operation was performed for a fixed period of time. Then dynamic mesh technique in FLUENT was used to study the impact of truck motion on DPM distribution. The resultant DPM distributions are presented for the cases when the vehicles were fitted with and without diesel particulate filters (DPF). The results from the simulation can be used to determine if the areas inside the single dead end entry exceed the current U.S. regulatory requirement for DPM concentration (160 µg/m3). This research can guide the selection of DPM reduction strategies and improve the working practices for the underground miners.

Simulation study of dispersion and removal of particulate matter from traffic by road-side vegetation barrier.

Well-positioned and configured vegetation barriers (VBs) have been suggested as one of the green infrastructures that could improve near-road (local) air quality. This is because of their influence on the underlying mechanisms: dispersion and mass removal (by deposition). Some studies have investigated air quality improvement by near-road vegetation barrier using the dispersion-related method while few studies have done the same using the deposition-related method. However, decision making on vegetation barrier's configuration and placement for need-based maximum benefit requires a combined assessment with both methods which are not commonly found in a single study. In the present study, we employed a computational fluid dynamics model, ENVI-met, to evaluate the air quality benefit of near-road vegetation barrier using an integrated dispersion-deposition approach. A technique based on distance between source (road) and point of peak concentration before dwindling concentration downwind begins referred to as "distance to maximum concentration (DMC)" has been proposed to determine optimum position from source and thickness of vegetation barrier for improved dispersion and deposition-based benefit, respectively. Generally, a higher volume of vegetation barrier increases the overall mass removal while it weakens dispersion of pollutant within the same domain. Hence, the benefit of roadside vegetation barrier is need-based and can be expressed as either higher mass deposition or higher mass dispersion. Finally, recommendations on applications of our findings were presented.

Mapping air pollution by biological monitoring in the metropolitan Tel Aviv area

Conventional environmental monitoring is not surrogate of personal exposure. In contrast, biomonitoring provides information on the presence of substances in the human body, making it highly relevant to the assessment of exposure to toxic substances. Induced sputum (IS) is a noninvasive technique for detecting inflammation and reflecting particulate matter content in the airways. In this study, we mapped particulate matter dispersion in metropolitan Tel Aviv by both biomonitoring techniques employing IS samples and by environmental monitoring. All adults referred to the Pulmonary Lab for respiratory symptom evaluation in 2007 and in 2009 were enrolled. Pulmonary function tests were performed by conventional methods. Particulate size distribution in IS was analyzed, and maps of air pollution were created. Biomonitoring was more informative and enabled mapping of wider areas. Integration of biomonitoring and environmental monitoring should be considered in forming public health policy on containment of airborne particles of toxic substances.

Effect of auxiliary ventilations on diesel particulate matter dispersion inside a dead-end entry

Diesel particulate matter (DPM) is considered carcinogenic after prolonged exposure. This paper used computational fluid dynamics (CFD) method to study the effect of four auxiliary ventilation systems on DPM distribution in a dead-end entry with loading operation. The auxiliary ventilation systems considered include: blower fan and tubing; exhaust fan and tubing, jet fan, and push–pull system. A species transport model with buoyancy effect was used to examine the DPM dispersion pattern with unsteady state analysis. During the 200 s of the loading operation, high DPM levels were identified in the face and dead-end entry regions. This study can be used for mining engineer as guidance to design and setup of local ventilation. It can also be used for selection of DPM control strategies and DPM annual training for underground miners.

Dispersion of atmospheric fine particulate matters in simulated lung fluid and their effects on model cell membranes

Atmospheric fine particulate matter (PM2.5) was collected to investigate its dispersion in simulated lung fluid (SLF) and its interaction with model cell membranes. Organic acids, NH4+, SO42− and NO3− were detected in PM2.5 soluble fraction, and heavy metals were detected from the total mass. The insoluble fraction contained kaolinite, CaCO3, aliphatic carbons, aromatic rings, carboxyl and hydroxyl groups reflected by the infrared spectra. Proteins dispersed PM2.5 in SLF, resulted in smaller hydrodynamic diameter (dH) and slower sedimentation rate. Conversely, phospholipids increased dH value and accelerated sedimentation rate. Giant unilamellar vesicles (GUVs) and supported lipid bilayers (SLBs) were used as model cell membranes. PM2.5 adhered on and disrupted the membrane containing positively-charged lipids but not the membrane containing neutrally- and negatively-charged lipids, which was monitored by microscopy and a quartz crystal microbalance with dissipation (QCM-D). The cationic sites on membrane were necessary for PM2.5 adhesion, but membrane should be disrupted by the combined action of electrostatic forces and hydrogen bonds between PM2.5 oxygen containing groups and the lipid phosphate groups. Our results specified the roles of proteins and phospholipids in PM2.5 dispersion and transport, highly suggested that the health hazard of PM2.5 was related to the biomolecules in the lung fluid and the particle surface groups.

Particulate matter concentrations originating from industrial and urban sources: Validation of atmospheric dispersion modeling results

This study presents the analysis of the emission, transport, dispersion, and concentration of particulate matter emitted from a large industrial complex dedicated to the manufacture of cement in the town of Malagueño, province of Córdoba (Argentina), using the USEPA's (Environmental Protection Agency) AERMOD model. The model was applied for 224 industrial and background emission sources (8 stacks, 3 limestone quarries, 13 material storage piles, 18 agricultural fields and 182 paved and unpaved segment roads). The application of the model was validated with Total Suspended Particulate matter (TSP) measured at two monitoring sites, where samples were collected for 62 consecutive days in winter. The maximum TSP values obtained at both monitoring sites (748 and 1100 μg m−3) were well above the suggested WHO guidelines. The results obtained showed the impact of this industrial activity on local particulate matter concentrations, from which unpaved industrial roads and stockpiles were the most influential emission sources, directly affecting two of the closest neighborhoods in the area. Future studies will include the accumulation of heavy metals and Polycyclic Aromatic Hydrocarbons in TSP samples, the environmental risk assessment for exposure of the Malagueño population and the source apportionment of these pollutants.

Simulation of particulate matter ingress, dispersion and deposition in a historical building

Abstract In this work, we use a computational fluid dynamics (CFD) model to simulate the penetration, dispersion and deposition of particulate matter (mean particle size of 2.5 μm) in a historical house. We compare the simulation results with direct measurements of deposition in several rooms and with measurements of concentration in different conditions of wind direction. The computational model, based on the drift-flux approach, provides accurate predictions of the spatial distribution of deposition and the variation of the indoor/outdoor ratio, which display a good agreement with experimental measurements. Our analysis shows that while the ingress rate of particles is controlled by wind direction and pressure, the amount of particles that reaches every surface depends ultimately on the operation of the ventilation system. Concentration indoors is relatively homogeneous, however, the spatial arrangement of the rooms and the position of air inlets and outlets results in significant gradients of deposition rates, which has direct implications for cleaning and preservation. These findings illustrate the potential of CFD to produce meaningful predictions of yearly and monthly deposition in large, multi-room environments, and to offer site-specific evidence, which can inform heritage managers and enable risk assessment.

Modeling a Multi-modal Distribution of Wind Direction Data in Kudat, Malaysia

Wind direction is the direction from which the wind is blowing. It is expressed in terms of degrees measured clockwise from geographical direction. The knowledge of the wind direction can be used to obtain information about the wind energy potential, dispersion of particulate matter in the air, the effects of engineering structures on the building, maritime study, and etc. This study provides a suitable model for the wind direction that indicates multi-modal distributional properties. A case study involves with a data from Kudat, Malaysia has been analysed. The statistical models known as a Finite Mixture of von Mises Fisher (mvMF) and Circular Distribution based on Nonnegative Trigonometric Sums (NNTS) has been fitted to the data. Then, the suitability of mvMF and NNTS models were judged based on a graphical representation and goodness-of-fit statistics. The results found that the mvMF model with components is sufficient to provide a best model.

Combined Influence of Stack Height and Exit Velocity on Dispersion of Pollutants Caused by Helwan Cement Factory (Study using AERMOD Model)

The cement industry plays a very important role in the growth of the national economy and the social development of any country. Therefore, severe restrictions and controls must be placed on cement industry to assess the environmental impacts of such projects not only before implementation but also during and after the operation of these projects. This research is about to introduce and build model using AERMOD model that can be used in environmental impact assessment of cement factories considering the effect of the stack height and exit gas velocity with one, two and three stacks, on the dispersion and the concentration of air emissions at receptor locations. The air dispersion model is used to predict the dispersion of particulate matter (PM10) and sulphur dioxide (SO2) emissions released from cement plant stack. Finally, the model showed that the stack heights and exit velocity are controlling factors in pollutant dispersion, where the relation between the stack height and the exit velocity against the maximum pollutant concentrations is inversely proportional. Moreover, this model was applied to a current cement plant located 30 Km south of Cairo. The emission concentrations from cement plant (8lines) were found to be less than the of Egyptian and International Environmental Laws. However, the emission concentrations from the cement plant when operated with full capacity (10lines) were found to violate the limits without background reading. General Terms Environmental Management.