Search for: air-pollution
Total 144 records
Article Urban Climate ; Volume 27 , 2019 , Pages 446-456 ; 22120955 (ISSN) ; Hassani, A ; Hosseini, V ; Sharif University of Technology
Elsevier B.V 2019
The city of Tehran, the capital of Iran, has been facing severe air quality problems. The air quality of Tehran has been stated as unhealthy over one-third of year during the last two decades. According to the last emission inventory of Tehran for the base year of 2013 mobile sources contribute by about 6, 46, 98, 87, and 70% of total primary SOx, NOx, CO, VOC and PM emission. A number of policies have been implemented in Tehran during the last two decades to tackle the air quality issue. Concentrated mostly on transportation sector, these policies aimed to improve fuel quality and emission performance of vehicles. Nevertheless, there is no quantified evaluation regarding the effectiveness...
Permissible emission limit estimation via iterative back-calculation: Case of Assaluyeh energy zone, southern Iran, Article Integrated Environmental Assessment and Management ; Volume 14, Issue 1 , 2018 , Pages 130-138 ; 15513793 (ISSN) ; Saboohi, Y ; Tsatsaronis, G ; Sharif University of Technology
In the present research work, an environmental policy procedure for setting a cap on emissions, as a crucial step in any total emission control system, has been provided and evaluated. It is shown that general regulations on emission intensities and rates do not guarantee that ambient air quality standards are met in intense industrial zones. Local emission limits are necessary to meet ambient air quality standards in these zones. To that end, we used dispersion simulators to back-calculate pollutant concentration thresholds for a large and intense energy system in the Assaluyeh region of southern Iran. Verified modeling results indicate 218 d of pollutant concentration threshold exceedance...
M.Sc. Thesis Sharif University of Technology ; Shayegan, jalaloddin ; Massoudinejad, Mohammad Reza
In this study, for removing ammonia from air, biofilters which is suitable method for removing odors, volatile organic compounds and toxic materials are used. Biofiltration is an efficient, easy and cost effective, environmental friendly process for degradation of ammonia from waste air. Aim of this study is comparative study of biofilters application for ammonia elimination from industrial sites.In order to remove ammonia, two columns with 14 cm inner diameter were used. One of the columns is filled with vermicompost and mineral shell (mineral shell : vermicompost, 1 : 4) and another column is filled with concentrated sludge and scallop (scallop : concentrated sludge, 2 : 3). Each of the...
Article Urban Climate ; Volume 17 , 2016 , Pages 216-229 ; 22120955 (ISSN) ; Taghvaee, S ; Hosseini, V ; Afshin, H ; Sharif University of Technology
Tehran with a population of 8.2 million urban residents, suffers from rapid urbanization in recent years resulting in severe air pollution. The aim of this study is to develop a high resolution emission inventory of primary air pollutants for Tehran. Tehran pollution sources are classified into two major categories. Mobile sources, including vehicles such as passenger car, taxi, motorcycle, pickup, minibus, bus and truck, and stationary sources; consisting of industries, general service and household, energy conversion, terminals and gas stations. The emission of SOx, NOx, CO, VOCs and PM in the year of 2013 were estimated as 37.411 kt, 85.524 kt, 506.690 kt, 83.640 kt and 8.496 kt,...
Characterizing the effect of traffic density on ambient CO, NO2, and PM2.5 in Tehran, Iran: an hourly land-use regression model, Article Transportation Letters ; 2017 , Pages 1-11 ; 19427867 (ISSN) ; Jamshidi, H ; Samimi, A ; Sharif University of Technology
Economic development and population growth in Tehran has increased demand for goods movement and road transportation. This trend has increased mobile source emissions and citizens’ exposure, imposing severe health risks. We used the framework of Land-Use Regression models to quantify the effect of real-time traffic, within buffer distance, on hourly exposure of CO, NO2, and PM2.5. Effect of residential, industrial, and governmental land-use in addition to the effect of pollution sources, such as construction sites and airport were assessed on air pollution. Meteorological variables were also employed to adjust between day variations. R-squared of the models were 38, 27, and 38% for CO, NO2,...
Article Atmospheric Pollution Research ; Volume 11, Issue 3 , 2020 , Pages 429-442 ; Hoshyaripour, A ; Shahbazi, H ; Hosseini, V ; Sharif University of Technology
Elsevier B.V 2020
An assessment of trends in main air pollutant concentrations (including CO, SO2, NO2, O3, PM2.5, and Asbestos) is conducted for the years 2005–2016 for the city of Tehran, Iran. The focus has been on the contribution of anthropogenic emissions to the observed trend, particularly the role of related mitigation plans implemented in the period of interest. A significant decreasing trend (about 50%) was observed in CO and SO2 concentrations during the considered time interval, which was explained by improvement plans in fuel quality and vehicle emission standards. While a substantial elevation (more than 50%) in NO2 levels was detected over the study period, variant trends were observed during...
Effect of cycling development as a non-motorized transport on reducing air and noise pollution-case study: Central districts of Tehran, Article Urban Climate ; Volume 38 , 2021 ; 22120955 (ISSN) ; Karimi, E ; Shahbazi, H ; Shahidzadeh, H ; Sharif University of Technology
Elsevier B.V 2021
The aim of this study was to investigate the possible reduction of air and noise pollution due to the substituent of motorcycles and personal vehicles with bicycles by the theoretical phase and to compare the exposure of a cyclist to noise pollution in using different modes of transportation in the field phase. In the theoretical phase, different scenarios were designed based on a 25% and 50% reduction in the volume of motorcycles and personal vehicles separately, as well as a simultaneous reduction of 50% for motorcycles and personal vehicles. The effect of running these scenarios on reducing air pollution was investigated using emission inventory model and on noise pollution by CadnaA...
Implementing spectral decomposition of time series data in artificial neural networks to predict air pollutant concentrations, Article Environmental Engineering Science ; Volume 32, Issue 5 , January , 2015 , Pages 379-388 ; 10928758 (ISSN) ; Zare Shahne, M ; Arhami, M ; Sharif University of Technology
Mary Ann Liebert Inc 2015
A model to predict air pollutants' concentrations was developed by implementing spectral decomposition of time series data, obtained by Kolmogorov-Zurbenko filter, in Artificial Neural Networks (ANN). This model was utilized to separate and individually predict three spectral components of air pollutants' time series of short, seasonal, and long-term. The best set of input variable was selected by evaluating the significance of different input variables while modeling different time series components. Moreover, different possible approaches for constructing such models were examined. Performance of the constructed model to predict air pollutants' level at a central location in Tehran, Iran,...
M.Sc. Thesis Sharif University of Technology ; Sohrabpour, Mostafa ; Khalafi, Hossein
Total air particulate matter of the city of Isfahan has been measured for elemental characterization in four principal directions of the city and during the year 2007-2008. High volume air samplers using whatman 41 filters have been utilized and instrumental neutron activation analysis has been used as the analytical method. Twenty one elements arising from seasonal and geographical distributions of the various elements have been determined. These distribution patterns have been discussed in view of the prevailing wind direction, location of the industrial facilities, and the Pearson correlation coefficients
Feasibilty Study of Using Condensation in Increasing Diameter of Airborne Particulate Matter to Enhance Control Efficiency, M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad
Particles with aerodynamic diameter of less than 10 μm can effectively pass through respiratory system and deposit on pulmonary areas wich cause adverse health effects. These particles are divided in to coarse particles (diameter: 2.5 to 10 μm) and fine particles (diameter < 2.5 μm). Fine particles can be more harmful for human’s health and harder to remove by air pollution control machines compare to coarse particle so it is crucial to find methods to enlarge the size of these particles. In this regards common methods such as utilizing electricity are costly and not efficient enough. Hence other economical and efficient methods such as using condensation are eamined. In this study the...
Prediction of Air Pollutants’ Hourly Concentration in Tehran Using Artificial Neural Network and Specteral Decomposition of Time Series Data, M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad
Recent progress in developing Artificial Neural Network (ANN) meta-models has paved the way for reliable use of these models in the prediction of air pollutant concentrations in urban atmosphere. However, improvement of prediction performance, proper selection of input parameters and model architecture remain key challenges to their practical use. This study’s main objectives are: selecting proper input parameters for ANN meta-models, optimizing the ANN models to achieve the most accurate hourly prediction for a case study (City of Tehran), coupling the ANN method with filtered input data and evaluating its privilege. In the current study the ANNs were constructed to predict criteria...
Light Duty Vehicles' Emission Reduction Potentials in Megacities
Sharif University of Technology
Erhami, M. (Mohammad)
Pourzahedi, H. (Hossein)
Using New Powertrain Technologies (Case Study: Tehran)
Tehran is one of the most polluted megacities in the world, and based on different studies, vehicular sources are responsible for most of the criteria pollutant emissions in this city. The number of vehicles on the streets has been increased drastically leading to growing amount of emission and this trend is continuing. In order to reduce the amount of vehicular emission, it is vital to investigate the factors affecting vehicles emission in this city. This could help to find efficient solutions to improve the situation. Hence, a low-cost methodology to estimate the vehicular emissions is developed. In this...
Article Industrial Health ; Volume 56, Issue 3 , 2018 , Pages 198-206 ; 00198366 (ISSN) ; Kokabi, A. H ; Dehghan, S. F ; Mehri, A ; Azam, K ; Golbabaei, F ; Sharif University of Technology
National Institute of Industrial Health 2018
Electric arc welding is a routine operation in the construction of metallic structures, but the fumes generated during the welding process can threaten the health of welders. Fumes are undesirable products of the majority of welding operations and may have various detrimental effects on health. The purpose of this study was to investigate the effect of operational parameters of the shielded metal arc welding SMAW process on the emission of fumes. A dust monitor was used to measure the number and mass concentration of fumes generated by SMAW. Measurements were made at the distances of 23 cm hood inlet and 41 cm welder’s breathing zone from the weld point, with different values assigned to...
Projecting emission reductions from prospective mobile sources policies by road link-based modelling, Article International Journal of Environment and Pollution ; Volume 53, Issue 1-2 , 2013 , Pages 87-106 ; 09574352 (ISSN) ; Arhami, M ; Sharif University of Technology
A methodology was developed to project total vehicular emissions from different emission reduction policies for the light-duty vehicles in the roads network of Tehran, Iran. A road-link-based model was constructed based on a bottom-up approach by coupling COPERT emission functions with the travel demand model of EMME/2. Results showed total emission from the studied network was largely impacted by vehicles' technology and age, speeds in the links, and fuel type. The proper transportation management to reduce the part of passenger cars and improve traffic flow also leads to a significant drop in the emission, e.g., emission decreased by 43% from 20% traffic volume reduction. Results indicated...
Article Air Quality, Atmosphere and Health ; Volume 9, Issue 8 , 2016 , Pages 909-921 ; 18739318 (ISSN) ; Mir, H. M ; Sharif University of Technology
Pollutant emission from vehicles is known as a major air pollution source in metropolitan areas. Efficiency of several solutions was quantified and compared to introduce the best solution for decreasing greenhouse gases and air pollutant emissions: (1) inspection and maintenance (I/M) of vehicles, (2) restriction of air conditioner usage, (3) injecting better quality fuel (removing sulfur), and (4) replacing older vehicles with new ones were modeled by International Vehicle Emissions (IVE) model as potential solutions. Restricting air conditioner usage makes an insignificant contribution in pollutants’ emission. The idle inspection/ maintenance system can reduce carbon monoxide (CO) and...
The impact of outcome framing and psychological distance of air pollution consequences on transportation mode choice, Article Transportation Research Part D: Transport and Environment ; Volume 46 , 2016 , Pages 328-338 ; 13619209 (ISSN) ; Behrang, K ; Isaai, M. T ; Nejat, P ; Sharif University of Technology
Recent years, air pollution phenomenon has become one of the crucial problems of Tehran, Iran. Due to main political and economic role of Tehran, population of this metropolis is high and increasing. Urban transportation of this highly populated city contributes more than 70% of air pollution problem in this city. Although a number of urban transport developments, policy measures and regulations have been employed, Tehran's air pollution has remained crucial thus far. Finding ways to encourage individuals to behave more sustainable can be considered as a substantial approach of tackling environmental problems such as air pollution, since it can be highly cost-effective and fast. This...
Developing air exchange rate models by evaluating vehicle in-cabin air pollutant exposures in a highway and tunnel setting: case study of Tehran, Iran, Article Environmental Science and Pollution Research ; 2018 ; 09441344 (ISSN) ; Arhami, M ; Delavarrafiee, M ; Ketabchy, M ; Sharif University of Technology
Springer Verlag 2018
The passengers inside vehicles could be exposed to high levels of air pollutants particularly while driving on highly polluted and congested traffic roadways. In order to study such exposure levels and its relation to the cabin ventilation condition, a monitoring campaign was conducted to measure the levels inside the three most common types of vehicles in Tehran, Iran (a highly air polluted megacity). In this regard, carbon monoxide (CO) and particulate matter (PM) were measured for various ventilation settings, window positions, and vehicle speeds while driving on the Resalat Highway and through the Resalat Tunnel. Results showed on average in-cabin exposure to particle number and PM10 for...
A variable turbulent Schmidt number formulation by numerical simulation of atmospheric plume dispersion, Article International Journal of Modern Physics C ; Volume 29, Issue 4 , 2018 ; 01291831 (ISSN) ; Ebrahimi, M ; Qate, M ; Sharif University of Technology
World Scientific Publishing Co. Pte Ltd 2018
Turbulent Schmidt number as an important parameter in computational fluid dynamic (CFD) simulations is strongly dependent on height, whereas it is mostly considered to be constant in the literature. This paper presents a new variable turbulent Schmidt number formulation which can calculate the relative concentrations (RCs) in neutral atmospheric conditions more accurately. To achieve this aim, RCs from continuous releases are calculated in different distances by the analytical Gaussian plume mode. CFD simulations are carried out for single stack dispersion on a flat terrain surface and an inverse procedure is then applied so that different turbulent Schmidt numbers are used as inputs to...
Article Urban Climate ; Volume 34 , December , 2020 ; Hosseini, V ; Sharif University of Technology
Elsevier B.V 2020
Tehran, the capital of Iran, is one of the most polluted cities in the Middle East. However, there is no clear evidence of the effects of Tehran green spaces on reducing air pollution because there are still challenges to application of vegetation for improving air quality. The current study investigates the effects of a large volume of green space with 275 ha area in the vicinity of major highways on nearby air quality. Similar environments are often seen in many cities around the world. A computational fluid dynamics model containing aerodynamics and deposition effects of vegetation was used to simulate pollutant dispersion for eight wind directions and three different foliage densities....
Article Atmospheric Pollution Research ; Volume 11, Issue 10 , 2020 , Pages 1839-1846 ; Lai, A. M ; de Foy, B ; Schauer, J. J ; Arhami, M ; Hosseini, V ; Sharif University of Technology
Elsevier B.V 2020
Each year, considerable levels of dust particles coming from arid regions of the earth contribute to the atmosphere. Because dust has serious environmental and human health effects, predictions of dust concentrations and their contribution to PM surface concentrations are essential for atmospheric research and the implementation of air quality programs and rules. This study aims to assess dust contributions to PM2.5 in Tehran in order to provide guidance for air quality management systems as well as validate the updated Dust Regional Atmospheric Model version 2 (BSC-DREAM8b) and the NMMB/BSC-Dust model using chemical speciation of ground-based measurements of PM2.5. Accurate and reliable...