scholarly journals Measurements and receptor modeling of volatile organic compounds in Southeastern Mexico City, 2000–2007

2010 ◽  
Vol 10 (18) ◽  
pp. 9027-9037 ◽  
Author(s):  
H. Wöhrnschimmel ◽  
M. Magaña ◽  
W. A. Stahel ◽  
S. Blanco ◽  
S. Acuña ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Weekend Effect ◽  
Receptor Modeling ◽  
Liquefied Petroleum Gas ◽  
Linear Regression Models ◽  
Vehicle Exhaust ◽  
Source Contributions ◽  
Volatile Organic

Abstract. Ambient samples of volatile organic compounds (VOCs) were measured between 2000 and 2007 in Southeastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene). These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective contributions. Domestic use of liquefied petroleum gas (LPG) and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to the total of quantified species. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source contributions. Furthermore, decreasing trends over time were found for LPG and hot soak (−7.8% and −12.7% per year, respectively, p < 0.01), whereas for vehicle exhaust no significant trend was found.

scholarly journals Measurements and receptor modeling of volatile organic compounds in south-eastern Mexico City, 2000–2007

2010 ◽  
Vol 10 (2) ◽  
pp. 3319-3346 ◽  
Author(s):  
H. Wöhrnschimmel ◽  
M. Magaña ◽  
W. A. Stahel ◽  
S. Blanco ◽  
S. Acuña ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Weekend Effect ◽  
Receptor Modeling ◽  
Liquefied Petroleum Gas ◽  
Linear Regression Models ◽  
Vehicle Exhaust ◽  
South Eastern ◽  
Volatile Organic

Abstract. Ambient samples of volatile organic compounds (VOCs) were measured between 2000 and 2007 in south-eastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene). These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several of the quantified VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective activities. Domestic use of liquefied petroleum gas and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to total VOC. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source activities. Furthermore, vehicle exhaust emissions showed a decreasing trend over time, with a reduction of about 8% per year.

Vertical profiles and receptor modeling of volatile organic compounds over Southeastern Mexico City

2006 ◽  
Vol 40 (27) ◽  
pp. 5125-5136 ◽  
Author(s):  
Henry Wöhrnschimmel ◽  
Claudia Márquez ◽  
Violeta Mugica ◽  
Werner A. Stahel ◽  
Johannes Staehelin ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Receptor Modeling ◽  
Vertical Profiles ◽  
Volatile Organic

scholarly journals Comparison of primary aerosol emission and secondary aerosol formation from gasoline direct injection and port fuel injection vehicles

2018 ◽  
Vol 18 (12) ◽  
pp. 9011-9023 ◽  
Author(s):  
Zhuofei Du ◽  
Min Hu ◽  
Jianfei Peng ◽  
Wenbin Zhang ◽  
Jing Zheng ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Fuel Injection ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Vehicle Exhaust ◽  
Port Fuel Injection ◽  
Gasoline Vehicles ◽  
Volatile Organic ◽  
The Impact

Abstract. Gasoline vehicles significantly contribute to urban particulate matter (PM) pollution. Gasoline direct injection (GDI) engines, known for their higher fuel efficiency than that of port fuel injection (PFI) engines, have been increasingly employed in new gasoline vehicles. However, the impact of this trend on air quality is still poorly understood. Here, we investigated both primary emissions and secondary organic aerosol (SOA) formation from a GDI and a PFI vehicle under an urban-like driving condition, using combined approaches involving chassis dynamometer measurements and an environmental chamber simulation. The PFI vehicle emits slightly more volatile organic compounds, e.g., benzene and toluene, whereas the GDI vehicle emits more particulate components, e.g., total PM, elemental carbon, primary organic aerosols and polycyclic aromatic hydrocarbons. Strikingly, we found a much higher SOA production (by a factor of approximately 2.7) from the exhaust of the GDI vehicle than that of the PFI vehicle under the same conditions. More importantly, the higher SOA production found in the GDI vehicle exhaust occurs concurrently with lower concentrations of traditional SOA precursors, e.g., benzene and toluene, indicating a greater contribution of intermediate volatility organic compounds and semi-volatile organic compounds in the GDI vehicle exhaust to the SOA formation. Our results highlight the considerable potential contribution of GDI vehicles to urban air pollution in the future.

scholarly journals Vehicular emission of volatile organic compounds (VOCs) from a tunnel study in Hong Kong

2009 ◽  
Vol 9 (19) ◽  
pp. 7491-7504 ◽  
Author(s):  
K. F. Ho ◽  
S. C. Lee ◽  
W. K. Ho ◽  
D. R. Blake ◽  
Y. Cheng ◽  
...  
Keyword(s):  
Hong Kong ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Abundant Species ◽  
Average Concentration ◽  
Ozone Formation ◽  
Liquefied Petroleum Gas ◽  
Key Species ◽  
Volatile Organic ◽  
Maximum Increment

Abstract. Vehicle emissions of volatile organic compounds (VOCs) were determined at the Shing Mun Tunnel, Hong Kong in summer and winter of 2003. One hundred and ten VOCs were quantified in this study. The average concentration of the total measured VOCs at the inlet and outlet of the tunnel were 81 250 pptv and 117 850 pptv, respectively. Among the 110 compounds, ethene, ethyne and toluene were the most abundant species in the tunnel. The total measured VOC emission factors ranged from 67 mg veh−1 km−1 to 148 mg veh−1 km−1, with an average of 115 mg veh−1 km−1. The five most abundant VOCs observed in the tunnel were, in decreasing order, ethene, toluene, n-butane, propane and i-pentane. These five most abundant species contributed over 38% of the total measured VOCs emitted. The high propane and n-butane emissions were found to be associated with liquefied petroleum gas (LPG)-fueled taxis. Fair correlations were observed between marker species (ethene, i-pentane, n-nonane, and benzene, toluene, ethylbenzene and xylenes – BTEX) with fractions of gasoline-fueled or diesel-fueled vehicles. Moreover, ethene, ethyne, and propene are the key species that were abundant in the tunnel but not in gasoline vapors or LPG. The ozone formation potential from the VOCs in Hong Kong was evaluated by the maximum increment reactivity (MIR). It was found to be 568 mg of ozone per vehicle per kilometer traveled. Among them, ethene, propene and toluene contribute most to the ozone-formation reactivity.

scholarly journals Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity

2008 ◽  
Vol 8 (4) ◽  
pp. 14273-14309 ◽  
Author(s):  
T. Karl ◽  
E. Apel ◽  
A. Hodzic ◽  
D. Riemer ◽  
D. Blake ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Eddy Covariance ◽  
Organic Compounds ◽  
Mexico City ◽  
Biomass Burning ◽  
Minor Role ◽  
Industrial Emissions ◽  
Tertiary Butyl ◽  
Volatile Organic ◽  
Flux Measurements

Abstract. Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC) fluxes of Volatile Organic Compounds (VOC) using Proton Transfer Reaction Mass Spectrometry (PTR-MS) on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC) flux measurements using PTR-MS are feasible. City-average midday toluene and benzene fluxes are calculated to be on the order of 15.5±4.0 mg/m2/h and 4.7±2.3 mg/m2/h respectively. These values argue for an underestimation of toluene and benzene emissions in current inventories used for the Mexico City Metropolitan Area (MCMA). Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10–15) including the International airport (e.g. 3–5) and a mean flux (concentration) ratio of 3.2±0.5 (3.9±0.3) across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (Benzene/Toluene/Ethylbenzene/m,p,o-Xylenes) compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE) and the biomass burning marker acetonitrile (CH3CN), we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >90% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds (0–10%) in the MCMA.

scholarly journals Receptor Model Source Apportionment of Nonmethane Hydrocarbons in Mexico City

2002 ◽  
Vol 2 ◽  
pp. 844-860 ◽  
Author(s):  
V. Mugica ◽  
J. Watson ◽  
E. Vega ◽  
E. Reyes ◽  
M.E. Ruiz ◽  
...  
Keyword(s):  
Mexico City ◽  
Motor Vehicle ◽  
Ambient Air ◽  
Nonmethane Hydrocarbons ◽  
Receptor Model ◽  
Liquefied Petroleum Gas ◽  
Vehicle Exhaust ◽  
Source Profiles ◽  
Source Contributions ◽  
Initial Source

With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC) to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas), asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

scholarly journals Evaporative volatile organic compounds from gasoline in Mexico City: Characterization and atmospheric reactivity

2020 ◽  
Vol 6 ◽  
pp. 825-830 ◽  
Author(s):  
V. Mugica-Alvarez ◽  
C.A. Martínez-Reyes ◽  
N.M. Santiago-Tello ◽  
I. Martínez-Rodríguez ◽  
M. Gutiérrez-Arzaluz ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Atmospheric Reactivity ◽  
Volatile Organic

Airborne Toxic Elements and Organic Substances (Ateos) Project: Overview

1990 ◽  
Vol 6 (5) ◽  
pp. 53-65
Author(s):  
Paul J. Lioy
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Indoor Air Pollution ◽  
Alkylating Agents ◽  
Receptor Modeling ◽  
Rural Setting ◽  
Urban Centers ◽  
Future Design ◽  
Volatile Organic ◽  
Particulate Mass

The approach and conclusions of the ATEOS project will be examined with an emphasis on future design considerations and strategies to address and reduce exposures. The ATEOS was a five year project that conducted field sampling in the summer and winter for the years 1981 through 1983. Eighty-five outdoor air pollutants were measured including the composition of inhalable particulate mass, and volatile organic compounds. The particulate mass components measured were the non-polar through polar organic fractions, polycyclic aromatic hydrocarbons, SO-24, trace elements and alkylating agents. From the numerous volatile organic compounds present in the atmosphere measurements were made of 10 chlorinated compounds, the automobile by products, e.g., benzene, o and p xylene, and 13 solvents. Other measurements included local meteorology. Besides the wealth of variables an important component of the study was the selection of the outdoor sites. The approach was to choose specific types of population — industrial-commercial locales with increasing (or decreasing) complexity. The sites were located in the New Jersey urban centers of Newark, Elizabeth and Camden, and a rural setting in Ringwood, N. J. The Newark site was the most complex industrial-commercial-residential interface followed in decreasing order by Elizabeth, Camden and Ring-wood. The manuscript will emphasize the characteristics of the measured variables in relation to the differences in the neighborhoods surrounding each site. Summary information on source — receptor modeling, pollution accumulation processes, episode analyses, and exposure assessment studies will be presented. These will be all evaluated with respect to future study design questions, including monitoring frequency, epidemiological exposure assessments and indoor air pollution.

scholarly journals Semiconductor Metal Oxides as Chemoresistive Sensors for Detecting Volatile Organic Compounds

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 233 ◽  
Author(s):  
Tingting Lin ◽  
Xin Lv ◽  
Zhineng Hu ◽  
Aoshu Xu ◽  
Caihui Feng
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Gas Sensors ◽  
Low Cost ◽  
Environmental Safety ◽  
Oil Refining ◽  
Detection Methods ◽  
Special Importance ◽  
Vehicle Exhaust ◽  
Volatile Organic

Volatile organic compounds (VOCs), which originate from painting, oil refining and vehicle exhaust emissions, are hazardous gases that have significant effects on air quality and human health. The detection of VOCs is of special importance to environmental safety. Among the various detection methods, chemoresistive semiconductor metal oxide gas sensors are considered to be the most promising technique due to their easy production, low cost and good portability. Sensitivity is an important parameter of gas sensors and is greatly affected by the microstructure, defects, catalyst, heterojunction and humidity. By adjusting the aforementioned factors, the sensitivity of gas sensors can be improved further. In this review, attention will be focused on how to improve the sensitivity of chemoresistive gas sensors towards certain common VOCs with respect to the five factors mentioned above.

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