A new experimental setup for measuring greenhouse gas and volatile organic compound emissions of silage during the aerobic storage period in a special silage respiration chamber

Livestock manure is one of the major sources of volatile organic compound (VOC) emissions; however, characteristics of VOCs emitted from biogas digestate (BD) storage, which is a common manure practice, remain unclear. The objective of this study was to characterize VOC emissions during BD storage through the dynamic emission vessel method, to identify the VOC emissions that have potential odor and/or toxic effects. The results revealed the detection of 49 VOCs with seven classes, whose total concentration varied from 171.35 to 523.71 μg m−3. The key classes of the 49 VOCs included Oxygenated VOCs (OVOCs), olefins and halogenated hydrocarbons. The top four compositions, accounting for 74.38% of total VOCs (TVOCs), included ethanol, propylene, acetone and 2-butanone. The top four odorous VOCs, accounting for only 5.15% of the TVOCs, were toluene, carbon disulfide, ethyl acetate and methyl sulfide, with the concentration ranging from 13.25 to 18.06 μg m−3. Finally, 11 main hazardous air pollutant VOCs, accounting for 32.77% of the TVOCs, were propylene, 2-butanone, toluene, methyl methacrylate, etc., with the concentration ranging from 81.05 to 116.96 μg m−3. Results could contribute to filling the knowledge gaps in the characteristics of VOC emissions from biogas digestate (BD), and provide a basis for exploring mitigation strategies on odor and hazardous air pollutions.

Improved emission factors and speciation to characterize VOC emissions in the printing industry in China

Concentrations and emissions of gasoline and other vapors from residential vehicle garages

Introduction The printing industry in China, with an annual output value of ¥1.43 trillion, is a significant source of volatile organic compound (VOC) emissions, which are key precursors to ozone formation. However, a comprehensive national-scale assessment linking VOC emissions to ozone formation potential (OFP) across major industrial zones has been lacking. Methods This study conducted a meta-analysis of VOC emissions and their OFP from China's printing industry, encompassing data from 14 major cities across three key regions: the Pearl River Delta, Yangtze River Delta, and Bohai Rim. The analysis integrated data on VOC speciation, concentrations, and pollution control technologies through a systematic review and harmonization of existing literature and industry data. Results Oxygenated Volatile Organic Compounds (OVOCs) dominated the emission profiles, accounting for 44.6%–81.1% of total VOC emissions. Isopropanol and ethyl acetate were identified as the predominant species, contributing 28.7% ± 5.3% and 24.1% ± 4.8% of total VOCs, respectively. Significant regional variations were observed, strongly linked to differences in ink types and printing processes. OFP values exhibited a wide range from 78.5 to 643.5 mg m −3 , with Changsha exhibiting the highest OFP, attributable to its prevalent use of gravure printing. Evaluation of pollution control technologies revealed widespread inefficiency, with 68% of enterprises relying on granular activated carbon (GAC), which typically achieves 40%–75% removal efficiency. In contrast, regenerative thermal oxidizers (RTOs) demonstrated superior performance, exceeding 90% efficiency. Discussion The findings highlight substantial regional disparities in emission profiles and OFP, driven by varying industrial practices and regulatory environments. The prevalence of inefficient control technologies like GAC underscores a critical gap in current pollution mitigation efforts. To effectively address VOC emissions and ozone formation, we recommend: (a) mandating the use of water-based inks in high-emission processes such as gravure and flexible packaging printing; (b) upgrading to advanced treatment technologies with >80% collection efficiency; and (c) implementing real-time VOC monitoring systems. This study provides a scientific basis for formulating targeted, region-specific VOC control strategies within China's crucial printing industry.

Volatile organic compound (VOCs) emissions from poultry and livestock facilities affect the surrounding environmental quality and human health. However, VOCs emissions from broiler houses have been less characterized, and studies of related dominant odorants, carcinogenic risk, and ozone formation potential are still lacking. To fill this research gap, VOCs pollutants emitted from a broiler house were investigated in this study. The VOCs emission characteristics of the broiler house during three different periods of broiler growth (early, middle, and later) were analyzed using gas chromatography-mass spectrometry. The results showed that 77 types of VOCs were detected, including 16 types of halogenated hydrocarbons, 21 types of alkanes, 5 types of olefins, 12 types of aromatic hydrocarbons, 15 types of oxygenated volatile organic compounds (OVOCs), and 8 types of sulfides. During the entire 42-day growth period, the concentrations of halogenated hydrocarbons, alkanes, olefin, aromatic hydrocarbons, and OVOCs in the broiler house showed few changes. However, with the growth of broilers, the intake of sulfur-containing amino acids and the fecal emission coefficient increased, resulting in the gradual conversion of the VOCs to sulfide. Therefore, emissions of sulfur-containing VOCs increased in the early and middle growth periods. Moreover, the increase in ventilation in the house during the later growth period resulted in a decrease in the sulfur-containing VOCs concentrations. The dominant odorants in the broiler house were naphthalene, ethyl acetate, acetaldehyde, carbon disulfide, dimethyl disulfide, methanethiol, methanethiol, and thiophene. Methanethiol had the highest odorous values, ranging from 2172.4 to 19090.9. Meanwhile, there were acceptable levels of carcinogenic risk in the early and middle growth periods, with a lifetime cancer risk (LCR) of 7.7×10-6 and 4.5×10-6, respectively. The average ozone formation potential (OFP) was (1458.9±787.4) μg·m-3. The results of this study can provide a scientific basis for the monitoring of malodorous substances and formulation of emission reduction strategies in broiler production.

The volatile organic compound (VOC) emission characteristics of various production procedures were analyzed through GC-MS after the emissions of typical enterprises such as automobile manufacturing, petrochemical, and other industries had been sampled with SUMMA canisters. Each production procedure in the automobile manufacturing and petrochemical industries was considered. The results showed that each automobile manufacturing procedure had its own dominant species, and alkanes (32%) and aromatics (35%) were the main emission species of coating spraying. The emission characteristics of furniture manufacturing were highly correlated with the raw materials, and the VOC emission species were mainly composed of aromatics (50%) and oxygenated VOCs (OVOCs) (38%). As for the petrochemical industry, VOC concentrations in various process plant areas ranged from 49 μg·m-3 to 1387 μg·m-3. As the main products of the refining area were C5-C9 gasoline and benzene series, whereas comparatively more solvents were used in the chemical area, which would generate alkene products, VOC concentrations greatly differed in the various process plant areas. In terms of electronic manufacturing, OVOCs were the main emission species, accounting for more than 50% of total VOCs. Alkanes and OVOCs were the main contributors to VOC emissions in shoemaking, accounting for 52% and 36% on average, respectively, which was strongly related to the species of the used solvents. The VOC emission species of automobile manufacturing were quite different, predominantly including n-dodecane and 2-butanone. The emission species of furniture manufacturing mainly included styrene, ethyl acetate, m/p-xylene, etc., which are typical species of coatings and diluents. As for the differences in the emission species of process plant areas in the petrochemical industry, styrene was the main species in the refining area, 1,3-butadiene in the chemical area, C3-C5 alkanes in the storage area, and C6-C8 alkanes in the wastewater treatment area. The main emission species of electronic manufacturing were ethanol, acetone, and other aldehyde ketone species. The emission species of shoemaking enterprises are mainly C5 and C6 alkanes. According to the results of ozone formation potential (OFP), alkenes and aromatics were the main VOC emission species that contribute significantly to the OFP in the automobile manufacturing and petrochemical industries, with relatively high pollution source reaction activity. The results showed that the emission ratio (17%-96%) and OFP contributions of OVOCs were significant in various industries. Therefore, for VOC emission control, in addition to focusing on the control of aromatics and alkenes, attention should also be paid to OVOCs.

Improving VOC control strategies in industrial parks based on emission behavior, environmental effects, and health risks: A case study through atmospheric measurement and emission inventory

Volatile organic compounds (VOCs)are important air pollutants in China, and control of their emission is an important subject of air pollution prevention and control.Architectural coatings play a significant role as sources of atmospheric VOCs in China.Due to recent economic development and increase in the levels of urbanization, the building of residences and other buildings is ongoing all the time, which results in increasing demand for architectural coatings and the VOCs pollution caused by painting operations.However, there are few studies of the VOCs emission factors and VOCs emissions due to architectural coatings.In this paper, a set of bottom-up VOCs emission inventory estimation methods for architectural coatings in China was established.The architectural coatings VOCs emission factors were gotten by actual measurement of VOCs in architectural coatings and by summarizing studies of VOCs contents in architectural coatings.Combining these results with the consumption of architectural coating sources, a VOCs emission inventory of architectural coatings in China from 2013 to 2016 was established.The results showed the following.① VOCs emission factors were 24.63 g·kg-1 for water-based interior wall coatings; 17.5 g·kg-1 and 298.8 g·kg-1 for water-based and solvent-based exterior wall coatings, respectively. They were 2.75, 87.86, and 400 g·kg-1 for water-based, reaction-type, and solvent-based waterproof coatings, respectively. For water-based, solventless, and solvent-based floor coatings, they were 86.2, 25.24, and 317 g·kg-1, respectively; and 31.95 g·kg-1 and 464.61 g·kg-1 for water-based and solvent-based anticorrosive coatings respectively. The emission factors were 59.7 g·kg-1 and 347.2 g·kg-1 for water-based and solvent-based fire retardant coatings, respectively. ② VOCs emissions from the use of architectural coatings were 255900 t, 287500 t, 319700 t, and 348000 t from 2013 to 2016 in China, with an upward trend. ③ Total VOCs emissions from architectural coatings was 348000 t in 2016, and the VOCs emissions from floor coatings was 78700 t, accounting for 22.61% with the maximum contribution rate. The VOCs emissions from exterior wall coatings were 64900 t, accounting for 18.65% (second place), and the VOCs emissions from fire retardant coatings and anticorrosive coatings (functional coatings) were 64500 t and 50800 t, accounting for 18.53% and 14.6% respectively. The VOCs emissions from waterproof coatings and interior wall coatings were 46100 t and 43000 t, accounting for 13.25% and 12.36%, respectively. ④ The consumption of water-based architectural coatings reached a total of 4889400 t in 2016 with VOCs emissions of 97900 t and average VOCs emissions factor of 20.02 g·kg-1; however, the consumption of solvent-based architectural coatings totaled 636500 t with VOCs emissions of 227200 t and average VOCs emission factor of 356.95 g·kg-1. Reducing the consumption of solvent-based coatings would be favorable for reduction of VOCs emissions. ⑤ As for the spatial distribution, architectural coating-related VOCs emissions were mainly concentrated in Shandong, Jiangsu, Zhejiang, Henan, Sichuan, Guangdong, and Hebei provinces, which have large populations. The province with the highest VOCs emissions was Shandong, with a percentage of 9.36%, and the second was Jiangsu, with a percentage of 8.54%.

SUMMA canisters were used to collect the exhaust gas from eight coating manufacturers in East China. A total of 106 VOCs was determined by gas chromatography-mass spectrometry (GC-MS) method to identify the emission characteristics of volatile organic compounds (VOCs) and the contribution of VOCs emitted by various companies to ozone generation, and the source profiles of solvent-based and water-based coatings were established. The results show that the characteristic components of VOCs in the coating manufacturing industry are mainly aromatic hydrocarbons and oxygenated hydrocarbons. The concentration ranges from 65.5% to 99.9%. The VOC emissions of solvent-based coatings were mainly aromatic hydrocarbons, accounting for 63.0%-94.0% of total VOCs; VOC emissions from waterborne coatings were mainly composed of oxygenated hydrocarbons, accounting for 54.5% to 99.9% of the total VOCs. m,p-xylene (32.4%), ethylbenzene (19.0%), and ethyl acetate (12.1%) were solvent-based coating sources, and ethyl acetate (83.7%) and 2-butyl ketone (8.0%) were the sources of waterborne coating emissions. Aromatic hydrocarbons and oxygenated hydrocarbons are the main active components in the coating manufacturing industry, with a total contribution to the ozone generation potential (OFP) ranging from 92.9% to 99.9%. Source reactivity (SR) analysis showed that the VOCs per unit mass of water-based coatings contributed much less to the formation of ozone than solvent-based coatings, so water-based coatings significantly reduced the potential for ozone generation. Studies have shown that for VOC pollution control in the coating manufacturing industry, attention should be paid to the VOCs that contribute more to the ozone-forming potential of aromatic hydrocarbons and oxygenated hydrocarbons, and VOC emissions should be controlled from the source.

Volatile organic compound emissions from an engine fueled with an ethanol-biodiesel-diesel blend

This study provides a comprehensive analysis of volatile organic compound (VOC) emissions in the context of 3D printing, a rapidly advancing technology that is transforming manufacturing processes. As the adoption of 3D printing grows, concerns regarding its potential impact on indoor air quality have emerged. This research addresses these concerns by investigating the risks associated with VOC emissions and proposing effective mitigation strategies. Using a robust methodology, filament and resin-based 3D printers were employed alongside VOC sampling equipment (Tenax tubes and personal pumps) to assess emissions. A detailed analysis of 49 VOCs revealed variable concentrations across different printing materials, with ethyl acetate being the dominant compound in resin printing and decanal in filament printing. While individual VOC levels were below 1% of occupational exposure limits, total VOC concentrations frequently exceeded the recommended indoor threshold of 200 µg/m3, particularly in resin-based processes. This raises concerns about the combined effects of multiple VOCs, some of which are known carcinogens. These findings underscore the need for further investigation into the cumulative health impacts of prolonged exposure to multiple VOCs. The study also emphasises the importance of accounting for both facility-specific conditions and material emissions to fully understand the environmental and health consequences of 3D printing. Preventative measures, such as enclosing 3D printers and equipping them with extraction systems, are recommended to safeguard user health.

Occupational health risks of VOCs emitted from the working face of municipal solid waste landfill: Temporal variation and influencing factors.

Rising temperatures amplify biogenic volatile organic compound (VOC) emissions from Arctic vegetation, causing feedbacks to the climate system. Changes in climate also alter plant physiology and vegetation composition, all of which can influence VOC emissions. Moreover, leaf development and biotic stresses cause highly variable emissions during the growing season. Therefore, linking VOC emissions with plant traits and tracking responses to climate change might provide better understanding of VOC emission regulation under future conditions. We measured VOC emissions and other plant traits in dwarf birch (Betula glandulosa) at two elevations in Narsarsuaq, South Greenland. The measurements were performed in warming experiments that have run since 2016. We collected VOCs using the branch enclosure method from early June until late July 2019 (n = 200). Emissions of green leaf volatiles (GLVs), oxygenated monoterpenes (oMTs), and homoterpenes followed a seasonal trend. VOC emission rates and the diversity of the VOC blend decreased at the end of the measurement period. Differences in VOC emission rates between elevations were pronounced early in the season. Majority of the traits did not explain the variation in VOC emissions. We show strong seasonal variability in VOC emissions within the growing season, which is likely driven by leaf phenology. While the diversity of VOCs was greater at the milder low‐elevation site, VOC emission rates were higher or similar at the harsher high‐elevation site, showing stronger VOC emission potentials than previously assumed. Seasonal variations in the emissions of VOCs are crucial for accurate predictions of current and future VOC emissions from arctic ecosystems.

Malodorous gases production from food wastes decomposition by indigenous microorganisms

Plant volatile organic compound (VOC) emissions can drive important climate feedbacks. Although mosses and lichens are important components of plant communities, their VOC emissions are poorly understood. It is crucial to obtain more knowledge on moss and lichen VOCs to improve ecosystem VOC emission models. This is especially relevant at high latitudes, where mosses and lichens are abundant and VOC emissions are expected to increase in response to climate change. In this study, we examined VOC emissions from four common moss (Hylocomium splendens, Pleurozium schreberi, Sphagnum warnstorfii, and Tomentypnum nitens) and lichen (Cladonia arbuscula, Cladonia mitis, Cladonia pleurota, and Nephroma arcticum) species in the Subarctic using gas chromatography-mass spectrometry (GC-MS) and proton-transfer-reaction time-of-flight mass spectrometry. Moss and lichen VOC emissions were dominated by low molecular weight (LMW) VOCs, such as acetone and acetaldehyde, as well as hydrocarbons (HCs) and oxygenated VOCs (oVOCs). Of the studied mosses, S. warnstrofii had the highest and H. splendens had the lowest total VOC emission rates. The VOC emission blends of P. schreberi, S. warnstrofii, and T. nitens were clearly distinct from one another. Of the lichens, N. arcticum had a different VOC blend than the Cladonia spp. N. arcticum also had higher emission rates of HCs, oVOCs, and other GC-MS-based VOCs, but lower LMW VOC emission rates than the other lichen species. Our study demonstrates that mosses and lichens emit considerable amounts of various VOCs and that these emissions are species dependent.