Spatial and temporal variation of BTEX in the urban atmosphere of Delhi, India

Hoque, Raza Rafiqul; Khillare, P. S.; Agarwal, Tripti; Shridhar, Vijay; Balachandran, S.

doi:10.1016/j.scitotenv.2007.08.036

Cited by 231 publications

(161 citation statements)

References 42 publications

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“…8d). The same results were also observed both in industry areas (Miller et al, 2012) and urban 25 areas (Ho et al, 2004;Hoque et al, 2008;Russo et al, 2010). The results obtained in this study indicated that there were other factors affecting the seasonal variation, such as source emissions.…”

Section: Ambient Ratios: Sources and Photochemical Removalsupporting

confidence: 85%

One year monitoring of volatile organic compounds (VOCs) from an oil-gas station in northwest China

Zheng

Kong

Xing

et al. 2017

Preprint

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Abstract. Oil and natural gas are important energy supply around the world. The exploring, drilling, transportation, and processing in oil-gas regions can release abundant volatile organic compounds (VOCs). To understand the atmospheric behaviors of VOCs in such region, the fifty-six VOCs designed as the photochemical precursors by the United State 15Environmental Protection Agency were continuously measured for an entire year (September 2014-August 2015) by a set of on-line monitor system at an oil-gas station in northwest China. The VOC concentrations in this study were 1-50 times higher than those measured in many other urban and industrial regions. The VOC compositions were also different from other studies with alkanes contributing up to 87.5% of the total VOCs in this study. According to the propylene-equivalent concentration and maximum incremental reactivity method, alkanes were identified as the most important VOC groups to the ozone 20 formation potential. The photochemical reaction, meteorological parameters (temperature, relative humidity, pressure, and wind speed) and boundary layer height were found to influence the temporal variations of VOCs at different time scales. The positive matrix factorization analysis showed that the natural gas, fuel evaporation, combustion sources, oil refining process, and asphalt contributed 62.6%, 21.5%, 10.9%, 3.8%, and 1.3%, respectively to the total VOCs on the annual average. Clear temporal variations differed from one source to another was observed, due to their differences in source emission strength and 25 the influence of meteorological parameters. Potential source contribution function and contribution weighted trajectory models based on backward trajectories indicated that five identified sources had similar geographic origins. Raster analysis based on CWT analysis indicated that the local emissions contributed 48.4%-74.6% to the VOCs. This research filled the gaps in understanding the VOCs in the oil-gas field region, where exhibited different source emission behaviors compared with the urban/industrial regions. 30

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Section: Ambient Ratios: Sources and Photochemical Removalsupporting

confidence: 85%

One year monitoring of volatile organic compounds (VOCs) from an oil-gas station in northwest China

Zheng

Kong

Xing

et al. 2017

Preprint

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“…Several authors (Hoque et al, 2008, and references therein) have performed correlation analyses to determine the possible source(s) for aromatic hydrocarbons. In this section, Pearson's correlation analyses were applied to correlate the concentrations of the different aromatic hydrocarbons Figure 6.…”

Section: Inter-compound Correlations: An Indication Of Sourcesmentioning

confidence: 99%

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

et al. 2014

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Abstract. Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol, which affect human health, crop production and regional climate. Measurements of aromatic hydrocarbons were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (> 10 million people), the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anticyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for 1 year. Samples were collected twice a week for 2 h during daytime and 2 h during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median (mean) total aromatic hydrocarbon concentrations ranged between 0.01 (0.011) and 3.1 (3.2) ppb. Benzene levels did not exceed the local air quality standard limit, i.e. annual mean of 1.6 ppb. Toluene was the most abundant compound, with an annual median (mean) concentration of 0.63 (0.89) ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found, and no distinct seasonal patterns were observed. Air mass back trajectory analysis indicated that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropogenically impacted regions. Inter-compound correlations and ratios gave some indications of the possible sources of the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropogenically impacted regions.

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“…Volatile organic compounds (VOCs) are hazardous compounds, which are contributed to various reactions in the atmosphere, i.e., the formation of photochemical oxidants (Haagen-Smit and Fox 1956;Atkinson 1997;Atkinson et al 1999;Hoque et al 2008) associated with smog, secondary organic fine particles and ground-level ozone (Tolnai et al 2000;Kim 2002;Truc and Oanh 2007). A group of compounds including benzene, toluene, ethylbenzene and xylenes (BTEX) belong to are a particular group of VOCs.…”

Section: Introductionmentioning

confidence: 99%

“…They are mainly emitted from road traffic in urban areas, and they could be found up to 60 % of nonmethane VOCs (Lee et al 2002;Parra et al 2006) and 35 % of total VOCs (Perry and Gee 1995;Fernández-Villarrenaga et al 2004). Vehicle exhaust is well known to be the main VOCs source in the atmosphere (Fujita et al 1994;Thijesse et al 1999;Na 2006;Hoque et al 2008), especially the emission of BTEX which are probably the most serious effects on air quality (Laowagul et al 2008). Despite their very low (ppb-ppt) concentrations, BTEX can affect both short and long terms to human health.…”

Section: Introductionmentioning

confidence: 99%

Development of low-cost passive sampler from cow bone char for sampling of volatile organic compounds

Tala

Chantara

Thiansem

et al. 2016

Int. J. Environ. Sci. Technol.

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A simple and low-cost passive sampler for collection of volatile organic compounds, specifically benzene, toluene, ethylbenzene and xylene (BTEX), from the ambient air has been developed by using cow bone char (CBC) as an adsorbent with desorption by solvent extraction prior to analysis by gas chromatography-mass spectrometry (GC-MS). The laboratory-made CBC was prepared by calcination process in a partially oxidative atmosphere. The developed passive sampler was tested for a suitable amount of CBC used, diffusion tube type and size, and sampling duration, in a closed chamber saturated with each of the BTEX vapors. With the optimum amount of 250 mg CBC packed in a glass bottle (82.6 mm height 9 11.1 mm i.d.) and the exposure time of 168 h, detection limits (lg/m 3 ) for BTEX determination using this developed sampler together with GC-MS were 0.28 (benzene), 0.79 (toluene), 0.58 (ethylbenzene), 0.28 (p-xylene) and 0.54 (o-xylene). The proposed method was applied to sampling BTEX from selected petrol stations, traffic congestion areas and a rural area in Chiang Mai Province, Thailand. The BTEX concentrations detected were well correlated with their sources as they were the highest at the petrol station sites, lower at the traffic congestion area sites and the lowest at the rural area site. The laboratory-made passive sampler containing CBC has thus opened up a possibility of having a simple and effective device for sampling of BTEX in the ambient air.

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Spatial and temporal variation of BTEX in the urban atmosphere of Delhi, India

Cited by 231 publications

References 42 publications

One year monitoring of volatile organic compounds (VOCs) from an oil-gas station in northwest China

One year monitoring of volatile organic compounds (VOCs) from an oil-gas station in northwest China

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

Development of low-cost passive sampler from cow bone char for sampling of volatile organic compounds

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