scholarly journals Measurement report: High contributions of halocarbon and aromatic compounds to atmospheric volatile organic compounds in an industrial area

2021 ◽  
Vol 21 (23) ◽  
pp. 18087-18099
Author(s):  
Ahsan Mozaffar ◽  
Yan-Lin Zhang ◽  
Yu-Chi Lin ◽  
Feng Xie ◽  
Mei-Yi Fan ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Kinetic Modelling ◽  
Industrial Area ◽  
Tropospheric Chemistry ◽  
Oh Radicals ◽  
Pmf Model ◽  
Volatile Organic ◽  
Secondary Air ◽  
Almost All

Abstract. Volatile organic compounds (VOCs) are key components of tropospheric chemistry. We investigated ambient VOCs in an industrial area in Nanjing, China, between July 2018 and May 2020. The sum of the suite of measured total VOC (TVOC) concentrations was 59.8 ± 28.6 ppbv (part per billion by volume) during the investigation period. About twice the TVOC concentrations were observed in the autumn (83 ± 20 ppbv) and winter (77.5 ± 16.8 ppbv) seasons compared to those in spring (39.6 ± 13.1 ppbv) and summer (38.8 ± 10.2 ppbv). In previous studies in Nanjing, oxygenated VOCs (OVOCs) and halocarbons were not measured, and the current TVOC concentration without halocarbons and OVOCs was similar to the previous investigation in the same study area. However, it was twofold higher than the one reported in the nonindustrial suburban area of Nanjing. Due to the industrial influence, the halocarbons VOC group (14.3 ± 7.3 ppbv, 24 %) was the second-largest contributor to the TVOCs after alkanes (21 ± 7 ppbv, 35 %), which is in contrast with the previous studies in Nanjing and also in almost all other regions in China. Relatively high proportions of halocarbons and aromatics were observed in autumn (25.7 % and 19.3 %, respectively) and winter (25.8 % and 17.6 %, respectively) compared to those in summer (20.4 % and 11.8 %, respectively) and spring (20.3 % and 13.6 %, respectively). According to the potential source contribution function (PSCF), short-distance transport from the surrounding industrial areas and cities was the main reason for the high VOC concentrations in the study area. According to positive matrix factorization (PMF) model results, vehicle-related emissions (33 %–48 %) contributed to the major portion of the ambient VOC concentrations. Aromatics, followed by alkenes, were the top contributors to the loss rate of OH radicals (LOH; 37 % and 32 %, respectively). According to the empirical kinetic modelling approach (EKMA) and relative incremental reactivity (RIR) analysis, the study area was in the VOC-sensitive regime for ozone (O3) formation during all measurement seasons. Therefore, alkenes and aromatics emissions from automobiles need to be decreased to reduce secondary air pollution formation in the study area.

scholarly journals An Integrated Method for Factor Number Selection of PMF Model: Case Study on Source Apportionment of Ambient Volatile Organic Compounds in Wuhan

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 390 ◽  
Author(s):  
Fenjuan Wang ◽  
Zhenyi Zhang ◽  
Costanza Acciai ◽  
Zhangxiong Zhong ◽  
Zhaokai Huang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Source Apportionment ◽  
Correlation Coefficient ◽  
Organic Compounds ◽  
Industrial Emissions ◽  
Integrated Method ◽  
Pmf Model ◽  
Volatile Organic ◽  
Measurement Period

The positive matrix factorization (PMF) model is widely used for source apportionment of volatile organic compounds (VOCs). The question about how to select the proper number of factors, however, is rarely studied. In this study, an integrated method to determine the most appropriate number of sources was developed and its application was demonstrated by case study in Wuhan. The concentrations of 103 ambient volatile organic compounds (VOCs) were measured intensively using online gas chromatography/mass spectrometry (GC/MS) during spring 2014 in an urban residential area of Wuhan, China. During the measurement period, the average temperature was approximately 25 °C with very little domestic heating and cooling. The concentrations of the most abundant VOCs (ethane, ethylene, propane, acetylene, n-butane, benzene, and toluene) in Wuhan were comparable to other studies in urban areas in China and other countries. The newly developed integrated method to determine the most appropriate number of sources is in combination of a fixed minimum threshold value for the correlation coefficient, the average weighted correlation coefficient of each species, and the normalized minimum error. Seven sources were identified by using the integrated method, and they were vehicular emissions (45.4%), industrial emissions (22.5%), combustion of coal (14.7%), liquefied petroleum gas (LPG) (9.7%), industrial solvents (4.4%), and pesticides (3.3%) and refrigerants. The orientations of emission sources have been characterized taking into account the frequency of wind directions and contributions of sources in each wind direction for the measurement period. It has been concluded that the vehicle exhaust contribution is greater than 40% distributed in all directions, whereas industrial emissions are mainly attributed to the west southwest and south southwest.

scholarly journals Petrochemical and Industrial Sources of Volatile Organic Compounds Analyzed via Regional Wind-Driven Network in Shanghai

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 760 ◽  
Author(s):  
Wanyi Qiu ◽  
Shule Li ◽  
Yuhan Liu ◽  
Keding Lu
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Surface Ozone ◽  
Industrial Area ◽  
Ozone Pollution ◽  
Regional Network ◽  
Local Circulation ◽  
Near Surface ◽  
Secondary Pollutants ◽  
Volatile Organic

Due to the development of industrialization and urbanization, secondary pollution is becoming increasingly serious in the Yangtze River Delta. Volatile organic compounds (VOCs) are key precursors of the near-surface ozone, secondary organic aerosol (SOA), and other secondary pollutants. In this study, we chose a serious ozone pollution period (01 May–31 July 2017) in Jinshan, which is a petrochemical and industrial area in Shanghai. We explored the VOCs distribution characteristics and contribution to secondary pollutants via constructing a regional network based on wind patterns. We determined that dense pollutants were accumulated at adjacent sites under local circulation (LC), and pollution from petrochemical discharge was more serious than industry for all sites under southeast (SE) wind. We also found that cyclopentane, o-xylene, m/p-xylene, 1-3-butadiene, and 1-hexene were priority-controlled species as they were most vital to form secondary pollutants. This study proves that regional network analysis can be successfully applied to explore pollution characteristics and regional secondary pollutants formation.

scholarly journals Source apportionment of volatile organic compounds in the northwest Indo-Gangetic Plain using a positive matrix factorization model

2019 ◽  
Vol 19 (24) ◽  
pp. 15467-15482 ◽  
Author(s):  
◽  
Baerbel Sinha ◽  
Vinayak Sinha
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Waste Disposal ◽  
Isocyanic Acid ◽  
Transport Sector ◽  
Emission Inventories ◽  
Gangetic Plain ◽  
Pmf Model ◽  
Volatile Organic ◽  
Indo Gangetic Plain

Abstract. In this study we undertook quantitative source apportionment for 32 volatile organic compounds (VOCs) measured at a suburban site in the densely populated northwest Indo-Gangetic Plain using the US EPA PMF 5.0 model. Six sources were resolved by the PMF model. In descending order of their contribution to the total VOC burden these are “biofuel use and waste disposal” (23.2 %), “wheat-residue burning”(22.4 %), “cars” (16.2 %), “mixed daytime sources”(15.7 %) “industrial emissions and solvent use”(11.8 %), and “two-wheelers” (8.6 %). Wheat-residue burning is the largest contributor to the total ozone formation potential (32.4 %). For the emerging contaminant isocyanic acid, photochemical formation from precursors (37 %) and wheat-residue burning (25 %) were the largest contributors to human exposure. Wheat-residue burning was also the single largest source of the photochemical precursors of isocyanic acid, namely, formamide, acetamide and propanamide, indicating that this source must be most urgently targeted to reduce human concentration exposure to isocyanic acid in the month of May. Our results highlight that for accurate air quality forecasting and modeling it is essential that emissions are attributed only to the months in which the activity actually occurs. This is important for emissions from crop residue burning, which occur in May and from mid-October to the end of November. The SOA formation potential is dominated by cars (36.9 %) and two-wheelers (21.1 %), which also jointly account for 47% of the human class I carcinogen benzene in the PMF model. This stands in stark contrast to various emission inventories which estimate only a minor contribution of the transport sector to the benzene exposure (∼10 %) and consider residential biofuel use, agricultural residue burning and industry to be more important benzene sources. Overall it appears that none of the emission inventories represent the regional emissions in an ideal manner. Our PMF solution suggests that transport sector emissions may be underestimated by GAINSv5.0 and EDGARv4.3.2 and overestimated by REASv2.1, while the combined effect of residential biofuel use and waste disposal emissions as well as the VOC burden associated with solvent use and industrial sources may be overestimated by all emission inventories. The agricultural waste burning emissions of some of the detected compound groups (ketones, aldehydes and acids) appear to be missing in the EDGARv4.3.2 inventory.

Interactions and implications of halogens and VOCs on tropospheric oxidant cycles in the remote atmosphere

2020 ◽  
Author(s):  
Eric C. Apel
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Model Development ◽  
Tropospheric Chemistry ◽  
Chemical Mechanism ◽  
Chemical Production ◽  
Four Seasons ◽  
The Pacific ◽  
Volatile Organic ◽  
Remote Troposphere

<p>Reactive halogens have wide-ranging consequences on tropospheric chemistry including ozone destruction, HOx and NOx partitioning, oxidization of volatile organic compounds (VOCs) and initiation of new particle formation. Of particular note and importance, the tropospheric Ox loss due to halogens is estimated to be between 10-20% globally, and up to 50% in some local marine environments. In this work, we include a state-of-the-art coupled halogen and VOCs chemical mechanism into the CAM-Chem global model. Complementing the model development and providing the opportunity to test the model are recent results from the NASA Atmospheric Tomography (ATom) experiment.  ATom was conducted with a heavily instrumented NASA DC-8 aircraft over the course of two and a half years, transecting the lengths of the Pacific and Atlantic Oceans during four seasons, constantly profiling from the surface (200 m) to the upper troposphere/lower stratosphere (12000 m). The ATom payload included instruments that measured both inorganic halogens and organic halogen-containing very short-lived substances (VSLS), as well as those that measured additional volatile organic compounds (VOCs), including hydrocarbons and oxygenated VOCs (OVOCs), both of which react with halogens. Modeled BrO is sensitive to the inclusion of reactions between Br and OVOCs, particularly the aldehydes, which rapidly convert Br to HBr, a far less reactive form of Br<sub>y</sub>. These reactions can have large implications in the remote troposphere where the ATom measurements have revealed significant emissions and chemical production of low molecular weight aldehydes over the remote marine environment. A version of CAM-chem, updated to include aldehyde emissions from the ocean to close the gap between models and measurements, is used in these analyses. Comparisons between measured and modeled halogen containing species, both organic and inorganic, is presented along with a summary of the implications of our findings on the overall budgets of tropospheric halogens and ozone.</p>

scholarly journals Monitoring of volatile organic compounds in ambient air of Taldykorgan, Kazakhstan

2019 ◽  
pp. 4-12
Author(s):  
Lyazzat Serik ◽  
Olga Ibragimova ◽  
Gulim Ussenova ◽  
Nassiba Baimatova
Keyword(s):  
Air Pollution ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Ambient Air ◽  
Volatile Organic ◽  
The World ◽  
Benzene Toluene ◽  
Almost All

The pollution of ambient air is one of the main sources of risk to human health in the world. There is a direct relationship between the level of air pollution and risk of the development of cancer, cardiovascular, respiratory and other diseases. Benzene, toluene, ethylbenzene and o-xylene (BTEX) are one of the most toxic volatile organic compounds. The aim of this study was to quantify BTEX in air of Taldykorgan, Kazakhstan using solid-phase microextraction followed by gas chromatography with mass-spectrometric detection. In different sampling seasons, average concentrations of four BTEX analytes varied from 7.5 to 27 µg/m3, from 15 to 250 µg/m3, from 2.4 to 12.8 µg/m3 and from 2.6 to 21 µg/m3, respectively. The highest concentrations of TEX were detected in autumn, while the highest concentrations of benzene were observed in winter. Toluene-to-benzene ratios in almost all measurements were above 1 indicating that the traffic emissions are the main source of air pollution with BTEX.

scholarly journals A mass balance-based emission inventory of non-methane volatile organic compounds (NMVOCs) for solvent use in China

2021 ◽  
Author(s):  
Ziwei Mo ◽  
Ru Cui ◽  
Bin Yuan ◽  
Huihua Cai ◽  
Brian C. McDonald ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Emission Inventory ◽  
Personal Care Products ◽  
Material Balance ◽  
Tropospheric Chemistry ◽  
Personal Care ◽  
Industrial Sectors ◽  
Volatile Organic ◽  
Solvent Use

Abstract. Non-methane volatile organic compounds (NMVOCs) are important precursors of ozone (O3) and secondary organic aerosol (SOA), which play key roles in tropospheric chemistry. A huge amount of NMVOCs emissions from solvent use are complicated by a wide spectrum of sources and species. This work presents a long-term NMVOCs emission inventory of solvent use during 2000–2017 in China. Based on a mass (material) balance method, NMVOCs emissions were estimated for six categories, including coatings, adhesives, inks, pesticides, cleaners and personal care products. The results show that NMVOC emissions from solvent use in China increased rapidly from 2000 to 2014 then kept stable after 2014. The total emission increased from 1.6 Tg (1.2–2.2 Tg at 95 % confidence interval) in 2000 to 10.6 Tg (7.7–14.9 Tg) in 2017. The substantial growth is driven by the large demand of solvent products in both industrial and residential activities. However, increasing treatment facilities on the solvent-related factories in China restrained the continued growth of solvent NMVOCs emissions in recent years. Rapidly developing and heavily industrialized provinces such as Jiangsu, Shandong and Guangdong contributed significantly to the solvent use emissions. Oxygenated VOCs, alkanes and aromatics were main components, accounting for 42 %, 28 % and 21 % of total NMVOCs emissions in 2017, respectively. Our results and previous inventories are generally comparable within the estimation uncertainties (−27 %–52 %). However, there exist significant differences in the estimates of sub-categories. Personal care products were a significant and quickly rising source of NMVOCs, which were probably underestimated in previous inventories. Emissions from solvent use were growing faster compared with transportation and combustion emissions which were relatively better controlled in China. Environmentally friendly products can reduce the NMVOCs emissions from solvent use. Supposing all solvent-based products were substituted by water-based products, it would result in 37 %, 41 % and 38 % reduction of emissions, OFP and SOAP, respectively. These results indicate there is still large room for NMVOCs reduction by reducing the utilization of solvent product and end-of-pipe control across industrial sectors.

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