WebDuring October 1993 rapid in-siru quasi-continuous GC/FID measurements of aromatic compounds (BTEX) were carried out at two urban sites in Munich/Germany. A cycle time … WebBTEX in the environment 3 4.1. Benzene (IPCS 1993, ATSDR 2007a, NTP 2005) Outdoor environmental levels of benzene range from 0.2 µg/m3 (0.06 ppb) in remote rural areas …
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WebAug 31, 2012 · The BTEX concentrations show that the average levels obtained from diurnal measurements are approximately 2X higher than those measured daily. The diurnal concentration/daily concentration … WebDec 21, 2024 · Average BTEX mixing ratios along with their associated arithmetic mean and interquartile range (IQR) in each period are listed in Table 1. Benzene and ethylbenzene were the most abundant BTEX compounds throughout the study period. On average, the highest concentrations of BTEX were observed during and after the lockdown. ...
WebOct 1, 1999 · This is supported by the concurrent observations of elevated BTEX mixing ratios and simultaneous daytime increases of both the toluene/m&p-xylene ratio and PAN mixing ratios. It demonstrates that BTEX compounds, in particular fast-reacting xylenes, play an important role in the photochemical smog formation on a regional scale. WebMar 14, 2005 · The use of multi-level soil samples to delineate and quantify the weathering of gasoline contamination is evaluated. Gasoline constituents with high effective solubilities (e.g., MTBE and BTEX) were found to be present over a wide range of total soil concentrations, with or without actual gasoline being present, in the soil samples. …
WebJan 13, 2024 · The ratios between BTEX species are important indicators to provide information about the different emission sources of these pollutants [59,60,61]. For example, the toluene/benzene ratios were <1 for biomass/biofuel/coal burning, 1–10 for vehicle emissions, and >1 for industrial processes and solvent applications [ 31 ]. WebDec 1, 2024 · The interspecies emission ratios can help to identify the dominant sources as well as to distinguish the aged and fresh emissions of BTEX. The ratios of T/B, m,p-X/B, o-X/B, and m,p-X/E for all sites based on the BTEX continuous monitoring data are presented in Supplementary 8. The average ratio of T/B at the UKMKL was 3.26 ± 1.02.
WebNov 1, 1995 · Concentration ratios of benzene, toluene, ethylbenzene, and xylenes (BTEX) in ground water can be used for ground-water contaminant plume differentiation and source determination. Computer modeling utilizing BTEX soil-water partitioning coefficients and biodegradation rates shows that hydraulic dispersion, retardation, and biodegradation do …
WebMar 13, 2024 · BTEX were monitored using passive samplers during two sampling seasons (rainy 2024 and cold dry 2024), and samples were analyzed by gas chromatography with flame ionization detection. BTEX ratios and meteorological analysis suggested that the concentrations were mainly influenced by vehicular and local sources located to the SE … strong arm clip art imagesWebToluene/benzene (T/B) ratio for all indoor sites (1.58- 2.20) indicated that gasoline fuel was the principle emission source. Ratio of T/B was always used as an indicator of vehicular emission [16, 17] and according to a study by Lan and Binh, T/B ratio of 2 indicated mainly a vehicular emission from petrol fuel in Malaysia. strong arm centering tool for clay amazonWebJun 16, 2015 · Burning incense indoors is a common behavior in Southeast Asia. In this investigation, needle trap samplers (NTS), a novel, green analytical technology is used for sampling gaseous combustion by-products from sandalwood incense coils. To extract indoor volatile organic compounds (VOCs), two NTS are prepared, one using 60–80 mesh and … strong arm clipart freeWebSep 15, 2024 · Catalytic oxidation of BTEX was performed at a constant initial concentration of the model components, a constant ratio of reactant and oxidant (synthetic air) and at different temperatures and space times. It was found that the technology of additive production (3D-printing), i.e. the process of stereolithography, makes it possible to ... strong arm carbon cleaningWebAug 23, 2024 · Except for a high peak at approximately 17:00 for BTEX and TVOCs, a similar variation pattern was observed for the BTEX (TVOCs), CO, and NOy mixing ratios. CO mainly originates from incomplete … strong arm cleaning westlockWebJun 15, 2014 · BTEX ratios can be useful as a tool to investigate photochemical processes (Yassaa et al. 2006). The ratio between m,p-xylene and ethylbenzene (m,p-X/E) is used to investigate the extent of atmospheric photochemical reactivity and is a useful tool for estimating the photochemical age of an air mass ... strong arm clipartWebNov 16, 2016 · An analysis of BTEX ratios shows that aromatic hydrocarbons in the sampled parks are mainly related to automobile emissions. High B/MTBE ratios (0.6–0.8) obtained in this study confirm car exhaust emissions as the main source of VOCs in underground car parks. Additional information about vehicles and their activities such as … strong arm coloring page