Part Of Volatile Organic Compounds Research Articles

Effect of Sulfur Dioxide as a Part of Volatile Organic Compounds (VOCs) of Lecanicillium fungi on Western Flower Thrips and Green Peach Aphid

Effect of Sulfur Dioxide as a Part of Volatile Organic Compounds (VOCs) of Lecanicillium fungi on Western Flower Thrips and Green Peach Aphid

Influence of Different Refueling Temperatures and Refueling Rates on Refueling Emission

With the increase of automobiles on hand in China, automobile refueling emissions, as an important part of volatile organic compounds (VOC), have been paid more and more attention. Frequent refueling is related to the fuel vapor concentration and operation safety of the gas stations. Reducing refueling emissions can improve fuel vapor recovery efficiency and reduce fuel waste in gas stations. Therefore, the research on refueling emissions test began to attract attention. However, due to the long pre-processing time of the refueling test, the occupation of the laboratory, and the complicated operation of testers, most studies in China focus on the numerical simulation of a simplified refueling model or the impact analysis of refueling emission of the local fuel system, and there are fewer studies on refueling emission of the whole automobile. This paper aims to analyze the influence of automobile refueling emissions on the environment more scientifically and reduce the fuel vapor loss in refueling more reasonably. The influence of different refueling temperatures and refueling rates on the refueling emission of the whole automobile was investigated. The research showed that automobile refueling emissions increased with the refueling temperature increasing. When the refueling temperature increased to a certain extent, fuel splashing occurred in refueling. When the refueling temperatures are 10°C, 30°C, and 40°C, the refueling emissions of vehicles equipped with ORVR system are 0.92 times, 3.08 times, and 8.29 times than the standard refueling temperature (20°C). In actual refueling, it was recommended to adopt the refueling temperature of 20°C. The refueling emissions decreased first and then increased with the refueling rate. The refueling emissions with the increase in refueling rate were lower than that with the decrease in refueling rate. When the refueling rate is 7L/min, 27L/min, 47L/min, the refueling emissions of vehicles equipped with the ORVR system are 13 times, 1.25 times, and 1.75 times that of the standard refueling rate (37L/min). Too high a refueling rate could lead to fuel splashing; therefore, a refueling rate of 37 L/min was recommended. Compared with ordinary gasoline vehicles and gasoline vehicles equipped with the ORVR system, it can be seen that vehicles equipped with the ORVR system can reduce refueling emissions by 99%. According to an industry report, 12320.4386t gasoline can be saved throughout the year if all vehicles are installed with the ORVR system in 2017 in Yunnan province. It will save 39.3730t and 149.6174t gasoline, when the gas station chooses a refueling temperature of 20 °C throughout the year, compared with the refueling temperature of 30°C and 40°C. And using a refueling rate of 37 L/min can save 4.7248t and 14.1743t gasoline, compared with the refueling rates of 27 L/min and 47 L/min throughout the year. Therefore, it is recommended that China continue to promote the installation of the ORVR system. In the actual refueling process, it is recommended to choose a lower refueling temperature and slower refueling rates to save energy.

Effect of Sulfur Dioxide as a Component of the Volatile Organic Compounds of Fungi of the Genus <i>Lecanicillium</i> on the Phytophagous Western Flower Thrips and Peach Aphid

Earlier, using the MS7-200 quadrupole mass spectrometer developed by the IAP RAS, sulfur dioxide was detected as part of volatile organic compounds (VoCs) released into the air by entomopathogenic fungi (EPF) of the genus Lecanicillium. In this work, we evaluated the effect of this compound on such dangerous phytophages as the Western flower thrips Frankliniella occidentalis and the peach aphid Myzus persicae in low doses corresponding to the content of sulfur dioxide in the composition of VOCs over the growing mycelium of fungi. It was found that sulfur dioxide did not have a negative effect on female thrips F. occidentalis and their fertility when sulfur dioxide is injected into vials at concentrations of 9 and 17 ppm and kept for 2 hours. At a dose of 33 ppm, sulfur dioxide caused a 10% mortality of female thrips after 2 hours and 15.4% after 1 day, while a 36% decrease in female fertility was observed. Sulfur dioxide at concentrations of 17-33 ppm was nontoxic for peach aphid females after 2 hours. Aphid mortality at the level of 26% was noted after 2 days at a sulfur dioxide concentration of 33 ppm, while fertility decreased by 22%. At a dose of 23 ppm, sulfur dioxide reduced the fertility of aphids most significantly - by 30%. The data obtained indicate the influence of sulfur dioxide contained in the composition of fungal VOCs on the behavioral reactions of phytophages.

Characteristics of VOCs and their Potentials for O3 and SOA Formation in a Medium-sized City in Eastern China

To understand the characteristics and environmental effects of volatile organic compounds (VOCs) in a typical medium-sized city in China, manual measurements including 56 species of the nonmethane hydrocarbons (NMHCs) were taken at three urban and suburban sites in Huai’an from April to September 2019, and automatic measurements including 106 species of VOCs were taken at the urban center in May and August 2019. Spatial and temporal characteristics of the VOC concentrations were analyzed. Positive matrix factorization (PMF) model was applied to apportion VOC sources. Ozone (O3) formation potentials (OFPs) and secondary organic aerosol (SOA) formation potentials (SOAFPs) were calculated. The results show that the mean VOC concentration was much lower in the urban center than in the suburbs. Generally, proportions of both alkenes and aromatic hydrocarbons were higher and proportion of alkanes was lower in Huai’an than that in big cities, indicating emissions from solvent usage and industrial process play a more important role in the medium-sized city. The results of source apportionment show that solvent usage and industrial process together contributed 53%, and vehicle emission contributed 27% to the ambient VOCs. The dependence of VOC concentrations on temperature indicates that a considerable part of VOCs may come from fugitive emissions. The two-peak pattern of diurnal variation suggests near-surface emissions contributed a lot to the VOCs. Aromatic hydrocarbons were identified as the key component to the formation of O3 and SOA. Furthermore, biogenic emission could contribute greatly (> 20%) to the ambient VOCs during daytime in summer, which may have significant effects on O3 formation. Aromatic hydrocarbons were identified as the key component to the formation of O3 and SOA, which should be given more attention in developing air pollution control strategies.

Simultaneous measurement of inhaled air and exhaled breath by double multicapillary column ion-mobility spectrometry, a new method for breath analysis: results of a feasibility study.

The high sensitivity of the methods applied in breath analysis entails a high risk of detecting analytes that do not derive from endogenous production. Consequentially, it appears useful to have knowledge about the composition of inhaled air and to include alveolar gradients into interpretation.The current study aimed to standardise sampling procedures in breath analysis, especially with multicapillary column ion-mobility spectrometry (MCC-IMS), by applying a simultaneous registration of inhaled air and exhaled breath.A “double MCC-IMS” device, which for the first time allows simultaneous analysis of inhaled air and exhaled breath, was developed and tested in 18 healthy individuals. For this, two BreathDiscovery instruments were coupled with each other.Measurements of inhaled air and exhaled breath in 18 healthy individuals (mean age 46±10.9 years; nine men, nine women) identified 35 different volatile organic compounds (VOCs) for further analysis. Not all of these had positive alveolar gradients and could be regarded as endogenous VOCs: 16 VOCs had a positive alveolar gradient in mean; 19 VOCs a negative one. 12 VOCs were positive in >12 of the healthy subjects.For the first time in our understanding, a method is described that enables simultaneous measurement of inhaled air and exhaled breath. This facilitates the calculation of alveolar gradients and selection of endogenous VOCs for exhaled breath analysis. Only a part of VOCs in exhaled breath are truly endogenous VOCs. The observation of different and varying polarities of the alveolar gradients needs further analysis.

Efficient purification of toluene gas by anoxic denitrification.

As a part of volatile organic compounds (VOCs), toluene does harm to human health. This paper reported the purification of toluene waste gas by liquid-phase absorption and anoxic denitrification. In this work, two same biofilm reactors were set to treat toluene waste gas, one of which was added into nitrate as an electron acceptor. Then, the purification properties of toluene waste gas treated by anoxic denitrification and biological methods were compared. The results indicate that with the increase of toluene mass concentration, the toluene removal rate of the denitrifying reactor decreased slightly. When the inlet concentration increased from 50mgm-3 to 3440mgm-3, the removal efficiency of the denitrifying reactor remained over 94.1% while the removal efficiency of the traditional bioreactor decreased to 82.9%. The highest removal capacity of the denitrifying reactor was 127.2gm-3h-1, which was 11.8% higher than that of the traditional bioreactor. Toluene was degraded by denitrification inside the biofilm microenvironment hypoxia; the denitrification rate increased along with the increase of inlet concentration within certain limits and reached a maximum of 2.4mg NO3--NL-1h-1. Nitrate can act as an electron acceptor, and denitrification can promote aerobic degradation and intensify the concentration gradient inside the biofilm to strengthen the toluene transfer process.

The Emission of the Floral Scent of Four Osmanthus fragrans Cultivars in Response to Different Temperatures.

Floral scent is an important part of volatile organic compounds (VOCs) emitted from plants, and is influenced by many environmental and endogenous factors. To investigate the influence of temperature on the emission of the floral scent of Osmanthus fragrans, the number of chemical compounds and their relative release amounts from four cultivars of O. fragrans under different temperature treatments, were identified using the solid-phase microextraction (SPME) technique and gas chromatography-mass spectrometry (GC-MS) in this study. Results revealed that the numbers and release amounts of floral scent components were significantly influenced by different temperatures, and depend on different cultivars and different types of compounds. Overall, most cultivars had the largest number of chemical compounds in 19 °C and the numbers of chemical compounds decreased with the increase or decrease in the temperature. Alcohols and ketones were the two main kinds of compounds responding to temperature change. The response of a specific chemical compound to temperature change was different in four cultivars. Generally, linalool, α-ionone, β-ionone, and γ-decalactone accounted for the highest proportion in the nine main compounds, and changes of these four chemical compounds to different temperatures had obvious contributions to the floral scent of O. fragrans. The results obtained provide evidence that temperatures can greatly influence the emission of floral scent.

Screening of volatile organic compounds in river sediment.

Volatile organic compounds (VOCs), such as trichloroethene, toluene and xylenes have been reported to be detected from river water and sediment, because a part of VOCs charged into river can be distributed to river sediment. Fifty-three common VOCs in water have been simultaneously determined with good accuracy and precision by gas chromatography - mass spectrometry (GC/MS) with headspace method as well as purge-and-trap method. However, simultaneous determination methods for the VOCs in sediment have not been established. Several GC or GOMS methods have been reported to determine some VOCs in sediment, purge-and-trap, distillation, headspace and solvent extraction. Among them headspace GC/MS method appears to be the most appropriate method for screening the VOCs in sediments, because of its simplicity in analytical procedure. Hewitt et al. have reported that headspace method gave no statistically different results from purge-and-trap method for GC/MS determination of four VOCs in soil. Voice and Kolb have reported that headspace GC method gave better results to determine nine VOCs in soil than purge-and-trap method or solvent extraction method followed by headspace. However, headspace analysis of some VOCs in sediments could give insufficient recoveries. This is because VOCs adsorb to sediment. To improve their low recoveries from sediment,more » we have previously used a stable isotope-labeled compound as an internal standard to determine eight chlorinated VOCs. However, this method is not proper for determining simultaneously as many as 53 VOCs with various physical properties. Therefore, we investigate headspace GC/MS method with standard addition method for simultaneous screening of them in sediment. In this paper, we describe effects of a few headspace conditions on the VOC recoveries from sediment, and present screening results of the VOCs in sediments from mouths of rivers and a port in Niigata, Japan. 17 refs., 3 figs., 3 tabs.« less