Near source modeling of pollutant emissions from an elevated source over an urban area under cross high ventilation

2021 ◽  
pp. 1-20
Author(s):  
Hammouda Mahjoub ◽  
Sahar Ben Romdhane ◽  
Nejla Mahjoub Said ◽  
Halemah Ibrahim El-Saeedy ◽  
Sami Znaidia ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Local Population ◽  
Three Dimensional ◽  
Pollutant Dispersion ◽  
Pollutant Emissions ◽  
Atmospheric Effects ◽  
Source Modeling ◽  
Rapid Urbanization ◽  
Elevated Source

Abstract Due to the rapid urbanization of many cities around the world, industrial manufacturing plants have grown rapidly, thus leading to the release of large amounts of pollutants into the environment. This is a main reason for the degradation of the local air quality, resulting in an increasing risk of unfavorable sanitary conditions for city dwellers. Understanding the dispersion of pollutants in local population environments, meteorological conditions and other physical characteristics is fundamental for predicting and evaluating air quality. This paper provides comprehensive details on the study of flow patterns and pollutant dispersion processes in urban areas. Several factors which include building geometry, local atmospheric effects, structural obstructions, and velocity of exhaust pollutants, are examined considering field data, wind tunnel tests, operational simulation techniques, and computational fluid dynamics. Good agreements are noticeable. Simultaneous evolutions of the velocity, thermal and scalar mass fraction fields of the pollutant emitting from a three-dimensional elevated source around a rectangular obstacle placed on a turbulent boundary layer wall, and also downstream the obstacle have been successfully carried out. The most serious pollutant levels in urban areas under various high wind velocities are identified.

scholarly journals Micrometeorological Modeling of Radiative and Convective Effects with a Building-Resolving Code

2011 ◽  
Vol 50 (8) ◽  
pp. 1713-1724 ◽  
Author(s):  
Yongfeng Qu ◽  
Maya Milliez ◽  
Luc Musson-Genon ◽  
Bertrand Carissimo
Keyword(s):  
Urban Areas ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Pollutant Dispersion ◽  
Urban Setting ◽  
Dynamical Model ◽  
Neutral Atmosphere ◽  
Atmospheric Flow ◽  
Ongoing Work ◽  
The One

AbstractIn many micrometeorological studies with computational fluid dynamics, building-resolving models usually assume a neutral atmosphere. Nevertheless, urban radiative transfers play an important role because of their influence on the energy budget. To take into account atmospheric radiation and the thermal effects of the buildings in simulations of atmospheric flow and pollutant dispersion in urban areas, a three-dimensional (3D) atmospheric radiative scheme has been developed in the atmospheric module of the Code_Saturne 3D computational fluid dynamic model. On the basis of the discrete ordinate method, the radiative model solves the radiative transfer equation in a semitransparent medium for complex geometries. The spatial mesh discretization is the same as the one used for the dynamics. This paper describes ongoing work with the development of this model. The radiative scheme was previously validated with idealized cases. Here, results of the full coupling of the radiative and thermal schemes with the 3D dynamical model are presented and are compared with measurements from the Mock Urban Setting Test (MUST) and with simpler modeling approaches found in the literature. The model is able to globally reproduce the differences in diurnal evolution of the surface temperatures of the different walls and roof. The inhomogeneous wall temperature is only seen when using the 3D dynamical model for the convective scheme.

scholarly journals EVALUATION OF METEOROLOGICAL FACTORS INFLUENCE ON BENZENE ACCIDENTAL POLLUTION. CASE STUDY: BACAU CITY 2008

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
DOINA CAPSA ◽  
VALENTIN NEDEFF ◽  
NARCIS BARSAN ◽  
Emilian Mosnegutu ◽  
DANA CHITIMUS
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Meteorological Factors ◽  
Pollutant Dispersion ◽  
Meteorological Factor ◽  
Climatic Conditions ◽  
Green Areas ◽  
Accidental Pollution ◽  
Industrial Waste Management

<p>Air quality depends on the type and size of industrial activities, traffic intensity, municipal and industrial waste management etc. In addition, air quality in urban areas depends by the green areas management, population density, climatic conditions and geographic. This paper study the correlations between the most important meteorological factors, humidity, temperature, wind and benzene accidental pollution, with influence on pollutant dispersion (related to 2008). The correlation were performed by taken in to considerations the accidental benzene pollution recorded in 2008 in Bacau City and meteorological factor recorded at the regional meteorological station.</p>

scholarly journals Correlation between Air Quality and Wastewater Pollution

2021 ◽  
Author(s):  
Karzan Mohammed Khalid
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Urban Areas ◽  
Wastewater Treatment Plants ◽  
Pollutant Emissions ◽  
Negative Effects ◽  
Environmental Technology ◽  
Wastewater Pollution ◽  
Pollutant Sources ◽  
Living Organisms

Recently, air pollution is a universal problematic concern which adversely affects global warming and more importantly human body systems. This chapter focuses on the importance of air quality, and indicates the negative effects of emissions originated from both municipal and industrial wastewaters to atmosphere. More importantly, the improvements in wastewater treatment plants to eliminate the crisis of emissions on environment and human health is also clarified. Urbanization and distribution of industrials in urban areas influence the air pollution via releasing pollutants and contaminants to environment. The pollutant emissions from wastewaters are volatile organic compounds, Greenhouse gases and other inorganic pollutants (heavy metals) which are causes to many reactions through atmosphere, then products detriment whole environment and living organisms including human. Moreover, contaminants are also released into air from influents of municipal wastewaters and they are considered as the main resources of most threatened infections in human and other animals. As conclusion, because of the persistently development urbanization and industrialization as the wastewater pollutant sources, the environmental technology regarding wastewater treatments must depend on prevention of emissions to air before thinking on cost and good quality effluents.

scholarly journals The Eulerian urban dispersion model EPISODE. Part II: Extensions to the source dispersion and photochemistry for EPISODE-CityChem v1.2 and its application to the city of Hamburg

2019 ◽  
Author(s):  
Matthias Karl ◽  
Sam-Erik Walker ◽  
Sverre Solberg ◽  
Martin O. P. Ramacher
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Urban Areas ◽  
Dispersion Model ◽  
Model Performance ◽  
Pollutant Dispersion ◽  
Lower Latitude ◽  
Urban Dispersion ◽  
Grid Model ◽  
The City

Abstract. This paper describes the CityChem extension of the Eulerian urban dispersion model EPISODE. The development of the CityChem extension was driven by the need to apply the model in lower latitude cities with higher insolation than in northern European cities. The CityChem extension offers a more advanced treatment of the photochemistry in urban areas and entails specific developments within the sub-grid components for a more accurate representation of the dispersion in the proximity of urban emission sources. The WMPP (WORM Meteorological Pre-Processor) is used in the point source sub-grid model to calculate the wind speed at plume height. The simplified street canyon model (SSCM) is used in the line source sub-grid model to calculate pollutant dispersion in street canyons. The EPISODE-CityChem model integrates the CityChem extension in EPISODE, with the capability of simulating photochemistry and dispersion of multiple reactive pollutants within urban areas. The main focus of the model is the simulation of the complex atmospheric chemistry involved in the photochemical production of ozone in urban areas. EPISODE-CityChem was evaluated with a series of tests and with a first application to the air quality situation in the city of Hamburg, Germany. A performance analysis with the FAIRMODE DELTA Tool for the air quality in Hamburg showed that the model fulfils the model performance objectives for NO2 (hourly), O3 (daily max. of the 8-h running mean) and PM10 (daily mean) set forth in the Air Quality Directive, qualifying the model for use in policy applications. Observed levels of annual mean ozone at the five urban background stations in Hamburg are captured by the model within 15 %. Envisaged applications of the EPISODE-CityChem model are urban air quality studies, emission control scenarios in relation to traffic restrictions and the source attribution of sector-specific emissions to observed levels of air pollutants at urban monitoring stations.

scholarly journals Computational Tools for Analysing Air Pollutants Dispersion: A Comparative Review

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1408 ◽  
Author(s):  
E. Antuña Yudego ◽  
JL. Carús Candás ◽  
E. Álvarez Álvarez ◽  
MJ. Suárez López ◽  
L. García ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Air Pollutants ◽  
Modern Society ◽  
Pollutant Dispersion ◽  
Computational Tools ◽  
Simulation Tools ◽  
Advantages And Disadvantages ◽  
Comparative Review ◽  
Pollutants Dispersion

Atmospheric pollution is one of the biggest problems and concerns in modern society, especially in industrial and highly populated areas. Poor air quality can have adverse impact on human health and ecosystems. For this reason, air quality forecasting becomes increasingly important, especially for governments and administrations, which use these predictions to enhance the design of mitigation actions in order to reduce air pollution in urban areas. In this framework, process of pollutant dispersion simulation is the best way to predict the most affected areas by industrial and other kinds of emissions. To carry out these simulations, there is a great number of computational tools currently available. However, not all of them have the same functionalities, nor can they be applied to the same case studies, so it is necessary to establish the advantages and disadvantages of each one of them in order to choose the most suitable tool in each case. Therefore, the objective of this paper is to identify the main available simulation tools and to make a comparative review between them in order to define advantages and disadvantages.

scholarly journals THREE-DIMENSIONAL DATA MODELLING FOR UNDERGROUND UTILITY NETWORK MAPPING

2018 ◽  
Vol XLII-4 ◽  
pp. 711-715 ◽  
Author(s):  
J. Yan ◽  
S. W. Jaw ◽  
R. V. Son ◽  
K. H. Soon ◽  
G. Schrotter
Keyword(s):  
Data Model ◽  
Urban Areas ◽  
City Planning ◽  
Three Dimensional ◽  
Accurate Information ◽  
Underground Space ◽  
Geospatial Information ◽  
Rapid Urbanization ◽  
Utility Network ◽  
City State

<p><strong>Abstract.</strong> Cities around the world face an increasing need for land as density in urban areas increases rapidly. The pressure to expand a city’s space is especially acute for a city-state like Singapore. How to make better use of underground space? This issue becomes much more emergent in the urban development. In the big data era, a data-driven approach of underground spaces is necessary for the sustainable development of a city along with rapid urbanization. A reliable three dimensional (3D) digital map of utility networks is crucial for urban planners to understand one of the most impactful aspects of the underground space planning. The mapping underground utility networks is a challenging task, especially for cities with limited land resources, congested underground spaces, and a lack of uniform existing practices. This paper proposes a framework to organise the workflow from an underground utility data survey to data use. This framework includes two core parts: A 3D utility network data model that aims to convert utility survey data to 3D geospatial information, and a 3D utility cadastral data model that supports utility ownership management. It is expected that reliable and accurate information on underground utility networks can lead to a better understanding and management of underground space, which eventually contributes to better city planning, making the unseen structures visible.</p>

Verifiable emission reductions in European urban areas with air-quality models

2016 ◽  
Vol 189 ◽  
pp. 617-633
Author(s):  
A. N. Skouloudis ◽  
D. G. Rickerby
Keyword(s):  
Air Quality ◽  
Numerical Modelling ◽  
Urban Areas ◽  
Local Population ◽  
Cost Effective ◽  
Population Exposure ◽  
Toxic Substances ◽  
Emission Reductions ◽  
New Approach ◽  
Emission Limits

The first and second AutoOil programmes were conducted since 1992 as a partnership between the European Commission and the automobile and oil industries. These have introduced emission reductions in Europe based on numerical modelling for a target year. They aimed to identify the most cost-effective way to meet desired future air quality over the whole European Union. In their time, these regulatory efforts were considered an important step towards a new approach for establishing European emission limits. With this work, we review the effectiveness of forecasts carried out with numerical modelling and compare these with the actual measurements at the target year, which was the year 2010. Based on these comparisons and new technological innovations these methodologies can incorporate new sectorial assessments for improving the accuracy of the modelling forecasts and for examining the representativeness of emissions reductions, as well as for the simultaneous assessment of population exposure to cocktails of toxic substances under realistic climatological conditions. We also examined at the ten AutoOil domains the geographical generalisation of the forecasts for CO and NO2 at 1065 European urban areas on the basis of their population and the local population density.

scholarly journals Effects of urban land expansion on the regional meteorology and air quality of eastern China

2015 ◽  
Vol 15 (15) ◽  
pp. 8597-8614 ◽  
Author(s):  
W. Tao ◽  
J. Liu ◽  
G. A. Ban-Weiss ◽  
D. A. Hauglustaine ◽  
L. Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Expansion ◽  
Eastern China ◽  
Urban Land ◽  
Pollutant Emissions ◽  
Ozone Pollution ◽  
Rapid Urbanization ◽  
Local Climate ◽  
Analysis Scheme ◽  
Concentration Changes

Abstract. Rapid urbanization throughout eastern China is imposing an irreversible effect on local climate and air quality. In this paper, we examine the response of a range of meteorological and air quality indicators to urbanization. Our study uses the Weather Research and Forecasting model coupled with chemistry (WRF/Chem) to simulate the climate and air quality impacts of four hypothetical urbanization scenarios with fixed surface pollutant emissions during the month of July from 2008 to 2012. An improved integrated process rate (IPR) analysis scheme is implemented in WRF/Chem to investigate the mechanisms behind the forcing–response relationship at the process level. For all years, as urban land area expands, concentrations of CO, elemental carbon (EC), and particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5) tend to decrease near the surface (below ~ 500 m), but increase at higher altitudes (1–3 km), resulting in a reduced vertical concentration gradient. On the other hand, the O3 burden, averaged over all newly urbanized grid cells, consistently increases from the surface to a height of about 4 km. Sensitivity tests show that the responses of pollutant concentrations to the spatial extent of urbanization are nearly linear near the surface, but nonlinear at higher altitudes. Over eastern China, each 10 % increase in nearby urban land coverage on average leads to a decrease of approximately 2 % in surface concentrations for CO, EC, and PM2.5, while for O3 an increase of about 1 % is simulated. At 800 hPa, pollutants' concentrations tend to increase even more rapidly with an increase in nearby urban land coverage. This indicates that as large tracts of new urban land emerge, the influence of urban expansion on meteorology and air pollution would be significantly amplified. IPR analysis reveals the contribution of individual atmospheric processes to pollutants' concentration changes. It indicates that, for primary pollutants, the enhanced sink (source) caused by turbulent mixing and vertical advection in the lower (upper) atmosphere could be a key factor in changes to simulated vertical profiles. The evolution of secondary pollutants is further influenced by the upward relocation of precursors that impact gas-phase chemistry for O3 and aerosol processes for PM2.5. Our study indicates that dense urbanization has a moderate dilution effect on surface primary airborne contaminants, but may intensify severe haze and ozone pollution if local emissions are not well controlled.

scholarly journals Response of atmospheric composition to COVID-19 lockdown measures during Spring in the Paris region (France)

2021 ◽  
Author(s):  
Jean-Eudes Petit ◽  
Jean-Charles Dupont ◽  
Olivier Favez ◽  
Valérie Gros ◽  
Yunjiang Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Meteorological Conditions ◽  
In Situ Monitoring ◽  
Pollutant Emissions ◽  
Atmospheric Composition ◽  
Secondary Pollutants ◽  
The Impact ◽  
Mitigation Policies

Abstract. Since early 2020, the COVID-19 pandemic has led to lockdowns at national scales. These lockdowns resulted in large cuts of atmospheric pollutant emissions, notably related to the vehicular traffic source where daily commuting of light-duty vehicles was almost completely stopped in numerous urban areas worldwide, especially during Spring 2020. As a result, air quality changed in manners that are still currently under investigation. Long-term in-situ monitoring of atmospheric composition provides, to this perspective, essential information. However, a robust quantitative assessment of the impact of lockdown measures on ambient concentrations is hindered by weather variability. Basic comparisons with previous years may thus be flawed, especially regarding secondary pollutants, whose concentrations strongly depends on meteorological conditions. In order to circumvent this difficulty, an innovative methodology has been developed. The Analog Application for Air Quality (A3Q) method is based on the comparison of each day of lockdown to a group of analog days having similar meteorological conditions. The A3Q method has been successfully evaluated and applied to a comprehensive in-situ dataset of primary and secondary pollutants obtained at the SIRTA observatory, a suburban background site of the Paris megacity (France). The overall slight decrease of PM1 concentrations (−14 %) compared to business-as-usual conditions conceals contrasting behaviours. Primary traffic tracers (NOx and traffic-related carbonaceous aerosols) dropped by 42–66 % during the lockdown period. Further, the A3Q method enabled us to characterize of changes triggered by NOx decreases. Particulate nitrate and secondary organic aerosols (SOA), two of the main springtime aerosol components in North-Western Europe, decreased by −45 % and −25 %, respectively. A NOx-relationship emphasizes the interest of NOx mitigation policies at the regional (i.e. city) scale, although long-range pollution advection sporadically overcompensated regional decreases. Variations of the oxidation state of SOA suggests discrepancies in SOA formation processes. At the same time, the expected ozone increase (+20 %) underlines the negative feedback of NO titration. These results provide a quasi-comprehensive observation-based insight on mitigation policies regarding air quality in future low-carbon urban areas.

scholarly journals Modeling the impact of COVID-19 on air quality in southern California: implications for future control policies

2021 ◽  
Vol 21 (11) ◽  
pp. 8693-8708
Author(s):  
Zhe Jiang ◽  
Hongrong Shi ◽  
Bin Zhao ◽  
Yu Gu ◽  
Yifang Zhu ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Southern California ◽  
Air Pollutant ◽  
Activity Level ◽  
Pollutant Emissions ◽  
Chemical Compositions ◽  
Emission Reductions ◽  
The Impact ◽  
Pm2.5 Concentration

Abstract. In response to the coronavirus disease of 2019 (COVID-19), California issued statewide stay-at-home orders, bringing about abrupt and dramatic reductions in air pollutant emissions. This crisis offers us an unprecedented opportunity to evaluate the effectiveness of emission reductions in terms of air quality. Here we use the Weather Research and Forecasting model with Chemistry (WRF-Chem) in combination with surface observations to study the impact of the COVID-19 lockdown measures on air quality in southern California. Based on activity level statistics and satellite observations, we estimate the sectoral emission changes during the lockdown. Due to the reduced emissions, the population-weighted concentrations of fine particulate matter (PM2.5) decrease by 15 % in southern California. The emission reductions contribute 68 % of the PM2.5 concentration decrease before and after the lockdown, while meteorology variations contribute the remaining 32 %. Among all chemical compositions, the PM2.5 concentration decrease due to emission reductions is dominated by nitrate and primary components. For O3 concentrations, the emission reductions cause a decrease in rural areas but an increase in urban areas; the increase can be offset by a 70 % emission reduction in anthropogenic volatile organic compounds (VOCs). These findings suggest that a strengthened control on primary PM2.5 emissions and a well-balanced control on nitrogen oxides and VOC emissions are needed to effectively and sustainably alleviate PM2.5 and O3 pollution in southern California.

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