Speciated Measurements and Calculated Reactivities of Vehicle Exhaust Emissions from Conventional and Reformulated Gasolines

1992 ◽  
Vol 26 (6) ◽  
pp. 1206-1216 ◽  
Author(s):  
S. Kent Hoekman
Keyword(s):  
Exhaust Emissions ◽  
Vehicle Exhaust

scholarly journals Spatiotemporal distribution of light-absorbing carbon and its relationship to other atmospheric pollutants in Stockholm

2011 ◽  
Vol 11 (22) ◽  
pp. 11553-11567 ◽  
Author(s):  
P. Krecl ◽  
A. C. Targino ◽  
C. Johansson
Keyword(s):  
Exhaust Emissions ◽  
Atmospheric Pollutants ◽  
Spatiotemporal Variability ◽  
Rural Site ◽  
Strong Increase ◽  
Population Exposure ◽  
Emission Sources ◽  
Vehicle Exhaust ◽  
Urban Background ◽  
Urban Sites

Abstract. Carbon-containing particles have deleterious effects on both Earth's climate and human health. In Europe, the main sources of light-absorbing carbon (LAC) emissions are the transport (67%) and residential (25%) sectors. Information on the spatiotemporal variability of LAC particles in urban areas is relevant for air quality management and to better diagnose the population exposure to these particles. This study reports on results of an intensive field campaign conducted at four sites (two kerbside stations, one urban background site and a rural station) in Stockholm, Sweden, during the spring 2006. Light-absorbing carbon mass (MLAC) concentrations were measured with custom-built Particle Soot Absorption Photometers (PSAP). The spatiotemporal variability of MLAC concentrations was explored by examining correlation coefficients (R), coefficients of divergence (COD), and diurnal patterns at all sites. Simultaneous measurements of NOx, PM10, PM2.5, and meteorological variables were also carried out at the same locations to help characterize the LAC emission sources. Hourly mean (± standard deviation) MLAC concentrations ranged from 0.36±0.50 at the rural site to 5.39±3.60 μg m−3 at the street canyon site. Concentrations of LAC between urban sites were poorly correlated even for daily averages (R<0.70), combined with highly heterogeneously distributed concentrations (COD>0.30) even at spatial scales of few kilometers. This high variability is connected to the distribution of emission sources and processes contributing to the LAC fraction at these sites. At urban sites, MLAC tracked NOx levels and traffic density well and mean MLAC/PM2.5 ratios were larger (26–38%) than at the background sites (4–10%). The results suggest that vehicle exhaust emissions are the main responsible for the high MLAC concentrations found at the urban locations whereas long-range transport (LRT) episodes of combustion-derived particles can generate a strong increase of levels at background sites. To decrease pollution levels at kerbside and urban background locations in Stockholm, we recommend abatement strategies that target reductions of vehicle exhaust emissions, which are the main contributors to MLAC and NOx concentrations.

scholarly journals Impact of freeway weaving segment design on light-duty vehicle exhaust emissions

2018 ◽  
Vol 68 (6) ◽  
pp. 564-575 ◽  
Author(s):  
Qing Li ◽  
Fengxiang Qiao ◽  
Lei Yu ◽  
Shuyan Chen ◽  
Tiezhu Li
Keyword(s):  
Exhaust Emissions ◽  
Vehicle Exhaust ◽  
Light Duty ◽  
Light Duty Vehicle

scholarly journals Pollution Characteristics of Atmospheric Carbonyls in Urban Linfen in Winter

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 685
Author(s):  
Fanxiu Li ◽  
Hengyuan Wang ◽  
Xuezhong Wang ◽  
Zhigang Xue ◽  
Liqin Duan ◽  
...  
Keyword(s):  
Urban Area ◽  
Atmospheric Chemistry ◽  
Mass Concentration ◽  
High Performance ◽  
Exhaust Emissions ◽  
Photochemical Reactions ◽  
Vehicle Exhaust ◽  
Pollution Characteristics ◽  
The North ◽  
Mass Concentrations

Atmospheric carbonyls (aldehyde and ketone compounds) can be precursors for ozone and PM2.5, and they play an essential role in atmospheric chemistry. Linfen is a basin between mountains on the east and west, and there are many coking plants on the north and south sides of its urban area. The special topography and unfortunate industrial layout have frequently contributed to serious air pollution in Linfen. In order to investigate the pollution characteristics of atmospheric carbonyls in winter in urban Linfen, the carbonyl compounds were collected from the Municipal Committee site (MC) and the Yaowangtai site (YWT) from 16 to 25 January 2019, and their concentrations were analyzed by a high performance liquid chromatography-ultraviolet detector (HPLC-UV). The results show that formaldehyde, acetaldehyde, and acetone were the most abundant compounds, accounting for more than 70% of the total mass concentration of carbonyls in urban Linfen. Levels of these three carbonyls increased during the morning and evening traffic rush hours. The mass concentration of formaldehyde at both sites reached peak values at around noon (10:00–14:00). In addition, the mass concentrations of formaldehyde, acetaldehyde, and acetone were positively correlated with CO mass concentrations, whereas only formaldehyde and acetaldehyde were positively correlated with temperature. Therefore, atmospheric formaldehyde in urban Linfen’s winter mainly came from vehicle exhaust emissions and the secondary generation of photochemical reactions. Most of the acetaldehyde came from vehicle exhaust emissions, and photochemical reactions also partially contributed to it. For acetone, vehicle exhaust emissions were the main source. In addition, coking industry emissions from Northern Linfen′s Hongtong County may also have contributed to the atmospheric carbonyls in the urban area of Linfen. For the first time, this study found that formaldehyde showed different behavior to acetaldehyde and acetone; that is, the nighttime decrease in formaldehyde mass concentration was greater than that of acetaldehyde and acetone.

scholarly journals Source Profiles for PM10-2.5 Resuspended Dust and Vehicle Exhaust Emissions in Central India

2018 ◽  
Vol 18 (7) ◽  
pp. 1660-1672 ◽  
Author(s):  
Shamsh Pervez ◽  
Shahina Bano ◽  
John G. Watson ◽  
Judith C. Chow ◽  
Jeevan Lal Matawle ◽  
...  
Keyword(s):  
Central India ◽  
Exhaust Emissions ◽  
Vehicle Exhaust ◽  
Source Profiles

scholarly journals Constructing an Environmental Friendly Low-Carbon-Emission Intelligent Transportation System Based on Big Data and Machine Learning Methods

2020 ◽  
Vol 12 (19) ◽  
pp. 8118
Author(s):  
Tu Peng ◽  
Xu Yang ◽  
Zi Xu ◽  
Yu Liang
Keyword(s):  
Sustainable Development ◽  
Environmental Pollution ◽  
Carbon Emissions ◽  
Carbon Emission ◽  
Intelligent Transportation ◽  
Exhaust Emissions ◽  
Low Carbon ◽  
Vehicle Exhaust ◽  
The Sustainable Development ◽  
Low Carbon Emission

The sustainable development of mankind is a matter of concern to the whole world. Environmental pollution and haze diffusion have greatly affected the sustainable development of mankind. According to previous research, vehicle exhaust emissions are an important source of environmental pollution and haze diffusion. The sharp increase in the number of cars has also made the supply of energy increasingly tight. In this paper, we have explored the use of intelligent navigation technology based on data analysis to reduce the overall carbon emissions of vehicles on road networks. We have implemented a traffic flow prediction method using a genetic algorithm and particle-swarm-optimization-enhanced support vector regression, constructed a model for predicting vehicle exhaust emissions based on predicted road conditions and vehicle fuel consumption, and built our low-carbon-emission-oriented navigation algorithm based on a spatially optimized dynamic path planning algorithm. The results show that our method could help to significantly reduce the overall carbon emissions of vehicles on the road network, which means that our method could contribute to the construction of low-carbon-emission intelligent transportation systems and smart cities.

scholarly journals Evaluating the Effects of One-Way Traffic Management on Different Vehicle Exhaust Emissions Using an Integrated Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jieyu Fan ◽  
Kun Gao ◽  
Yingying Xing ◽  
Jian Lu
Keyword(s):  
Traffic Management ◽  
Integrated Approach ◽  
Exhaust Emissions ◽  
Traffic Emissions ◽  
Specific Power ◽  
Emission Measurement ◽  
Emission Rates ◽  
Vehicle Exhaust ◽  
Emission Data ◽  
The Road

One-way traffic management is a recognized traffic organization to improve traffic efficiency and safety, but its effects on different traffic emissions remains unclear. This paper aims to investigate the impacts of one-way traffic management on three typical vehicle exhaust emissions including Carbonic Oxide (CO), Hydrocarbon Compounds (HC), and Nitrogen Oxides (NOx) in a traffic system using an integrated approach. Field experiment was conducted to collect the vehicular emission data under different traffic conditions using the onboard portable emission measurement system. An instantaneous emission model (i.e., Vehicle Specific Power) is calibrated using the collected field emission data and is incorporated into the microscopic traffic simulation tool VISSIM for quantifying the emissions before and after one-way traffic management through simulation. Two scenarios based on real networks and traffic demands of peak hours in part areas of Shanghai are developed for simulation and evaluation. The results show that in the intersections, the emission rates of COHC, NOx after one-way traffic management is significantly reduced by 20.46%, 21.29% and 21.06%, respectively. In the road sections, the emission rates of CO, HC, NOx in the road sections decrease by 23.38% and 26.29%. The overall CO, HC, NOx emissions in the studied network reduce by 21.34%, 22.29% and 23.77% separately due to one-way traffic management. The results provide insights into the derivative effects of one-way traffic management on traffic emissions in the intersections, road sections and network levels, and thus support scientific traffic management for promoting the sustainability of transport system.

scholarly journals Nitrous acid (HONO) emissions under real-world driving conditions from vehicles in a UK road tunnel

2019 ◽  
Author(s):  
Louisa J. Kramer ◽  
Leigh R. Crilley ◽  
Thomas J. Adams ◽  
Stephen M. Ball ◽  
Francis D. Pope ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Nitrous Acid ◽  
Vehicle Emissions ◽  
New Technologies ◽  
Major Axis ◽  
Exhaust Emissions ◽  
City Centre ◽  
Traffic Density ◽  
Vehicle Exhaust ◽  
Road Tunnel

Abstract. Measurements of atmospheric boundary layer nitrous acid (HONO) and nitrogen oxides (NOx) were performed in summer 2016 inside a city centre road tunnel in Birmingham, United Kingdom. HONO and NOx mixing ratios were strongly correlated with traffic density, with peak levels observed during the early evening rush hour as a result of traffic congestion in the tunnel. A daytime ΔHONO / ΔNOx ratio of 0.85 % (0.72–1.01 %, 95 % CI) was calculated using reduced major axis regression as the overall fleet-average (comprising 59 % diesel-fuelled vehicles). A comparison with previous tunnel studies and analysis on composition of the fleet suggest that goods-vehicles have a large impact on the overall HONO vehicle emissions; however, new technologies aimed at reducing exhaust emissions, particularly for diesel vehicles, may have reduced the overall direct HONO emission in the UK. This result suggests that in order to accurately represent urban atmospheric emissions and OH radical budget, fleet-weighted HONO / NOx ratios may better quantify HONO vehicle emissions in models, compared with use of a single emissions ratio for all vehicles. The contribution of the direct vehicular source of HONO to total ambient HONO concentrations is also investigated and results show that, in areas with high traffic density, vehicle exhaust emissions are likely to be the dominant HONO source to the boundary layer.

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