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1
Carmen, Florean, Henriette Szilagyi e Andreea Hegyi. "Environment and Pollution Management of Pollution Volatile Organic Compounds in Cluj-Napoca". Present Environment and Sustainable Development 10, n. 2 (1 ottobre 2016): 207–17. http://dx.doi.org/10.1515/pesd-2016-0038.
Testo completoAbstract (sommario):
Abstract Pollution negative influences the environmental, human health, buildings and increase the production of waste. We are currently witnessing pollution and degradation in some cases irreversible, of the environment. Environmental issues are extremely complex and cover all sectors. Worldwide, industrial pollution strategies necessary to reduce emissions to the atmosphere hydrocarbons, volatile organic compounds (VOCs) and other polluants in urban areas. The highest concentrations of volatile organic compounds of more than 80 mg/m3 occur in densely populated areas. The latest data reported in the residential area of Cluj-Napoca values did not exceed 20 m /m3. However peaks reported VOC concentrations, depending on the season, exceeding the upper limit that according to Law. 104/2011 is 75 μ/m3. It was identified due to increase annual mean concentration of VOCs as, in particular, road traffic exceeding sanitary standards on the main traffic routes within the city. In this paper the results obtained after carrying out an analysis of the average VOC concentration recorded in the city Cluj-Napoca as a result of car traffic. They were pursued average concentrations of VOCs resulting from the combustion of liquid fuels, petrol and diesel type. Analyzing the results obtained are proposed solutions for reducing VOC emissions. The rule under which these solutions have been proposed to reduce the concentration of VOCs took into account the possibility implementation and maintenance costs thereof.
2
Cui, Lulu, Di Wu, Shuxiao Wang, Qingcheng Xu, Ruolan Hu e Jiming Hao. "Measurement report: Ambient volatile organic compound (VOC) pollution in urban Beijing: characteristics, sources, and implications for pollution control". Atmospheric Chemistry and Physics 22, n. 18 (15 settembre 2022): 11931–44. http://dx.doi.org/10.5194/acp-22-11931-2022.
Testo completoAbstract (sommario):
Abstract. The increasing ozone (O3) pollution and high fraction of secondary organic aerosols (SOA) in fine particle mass has highlighted the importance of volatile organic compounds (VOCs) in air pollution control. In this work, four intensive field measurements of VOCs during winter of 2018 (from 1 December 2018 to 17 January 2019), spring (15 April to 27 May), summer (17 June to 13 July), and autumn (22 September to 27 November) of 2019 were conducted at an urban site in Beijing to characterize VOC sources and their contributions to air pollution. The total mixing ratio of the 95 quantified VOCs (TVOC) observed in this study ranged from 5.5–118.7 ppbv with the mean value of 34.9 ppbv. Alkanes, OVOCs, and halocarbons were the dominant chemical groups, accounting for 75 %–81 % of the TVOC across the sampling months. The molar ratios of VOCs to NOx indicated that O3 formation was limited by VOCs during the whole sampling period. Positive matrix factorization (PMF) analysis showed that diesel vehicle exhaust, gasoline vehicle exhaust, and industrial emissions were the main VOC sources during both the O3-polluted and PM2.5-polluted months. On the basis of O3 formation impact, VOCs from fuel evaporation and diesel exhaust, particularly toluene, xylenes, trans-2-butene, acrolein, methyl methacrylate, vinyl acetate, 1-butene, and 1-hexene, were the main contributors, illustrating the necessity of conducting emission controls on these pollution sources and species to alleviate O3 pollution. Instead, VOCs from diesel exhaust as well as coal and biomass combustion were found to be the dominant contributors to secondary organic aerosol formation potential (SOAFP), particularly the VOC species of toluene, 1-hexene, xylenes, ethylbenzene, and styrene, and top priority should be given to these for the alleviation of haze pollution. This study provides insights for the government to formulate effective VOC control measures for air pollution in Beijing.
3
Wang, Qi, Chēn Wang, Lujian Hou, Bo Lv e Chén WANG. "Pollution data analysis and characteristics of volatile organic compounds in the environment". E3S Web of Conferences 38 (2018): 01004. http://dx.doi.org/10.1051/e3sconf/20183801004.
Testo completoAbstract (sommario):
Volatile organic compounds (VOCs) have a wide range of sources and have a significant impact on the ecological environment and human health, which have attracted wide attention of many researchers. In this paper, the pollution characteristics of VOCs, the role of VOCs in atmospheric chemistry including OH reaction reactivity (LOH), Ozone Formation Potential (OFP) and SOA generation potential (SOAP), VOCs source apportionment were discussed and reviewed.
4
Ma, Wei, Zemin Feng, Junlei Zhan, Yongchun Liu, Pengfei Liu, Chengtang Liu, Qingxin Ma et al. "Influence of photochemical loss of volatile organic compounds on understanding ozone formation mechanism". Atmospheric Chemistry and Physics 22, n. 7 (12 aprile 2022): 4841–51. http://dx.doi.org/10.5194/acp-22-4841-2022.
Testo completoAbstract (sommario):
Abstract. Volatile organic compounds (VOCs) tend to be consumed by atmospheric oxidants, resulting in substantial photochemical loss during transport. An observation-based model was used to evaluate the influence of photochemical loss of VOCs on the sensitivity regime and mechanisms of ozone formation. Our results showed that a VOC-limited regime based on observed VOC concentrations shifted to a transition regime with a photochemical initial concentration of VOCs (PIC-VOCs) in the morning. The net ozone formation rate was underestimated by 3 ppb h−1 (∼36 ppb d−1) based on the measured VOCs when compared with the PIC-VOCs. The relative contribution of the RO2 path to ozone production based on the PIC-VOCs accordingly increased by 13.4 %; in particular, the contribution of alkene-derived RO2 increased by approximately 10.2 %. In addition, the OH–HO2 radical cycle was obviously accelerated by highly reactive alkenes after accounting for photochemical loss of VOCs. The contribution of local photochemistry might be underestimated for both local and regional ozone pollution if consumed VOCs are not accounted for, and policymaking on ozone pollution prevention should focus on VOCs with a high reactivity.
5
Liu, Hefan, Ning Wang, Dongyang Chen, Qinwen Tan, Danlin Song e Fengxia Huang. "How Photochemically Consumed Volatile Organic Compounds Affect Ozone Formation: A Case Study in Chengdu, China". Atmosphere 13, n. 10 (20 settembre 2022): 1534. http://dx.doi.org/10.3390/atmos13101534.
Testo completoAbstract (sommario):
Surface ozone (O3) pollution has not improved significantly in recent years. It is still the primary air pollution problem in many megacities in China during summertime. In high temperature and intense radiation weather, volatile organic compounds (VOCs) are easily oxidized and degraded to induce O3 pollution. In order to understand the impact of difference between photochemical initial concentration (PIC) of VOCs and the actual measured concentration on O3 formation, a campaign was carried out during O3 pollution in Chengdu (25 July–5 August 2021). During this O3 pollution episode, the maximum value of O3 concentration reached 335.0 μg/m3, and the precursor concentrations increased significantly. The mean values of VOCmeasured and VOCPICs were 19.7 ppbv and 30.7 ppbv, corresponding to O3 formation potential (OFP) of 175.3 μg/m3 and 478.8 μg/m3, respectively, indicating that the consumption of VOCs content could not be ignored. Alkenes accounted for 77.2% of VOCs consumption. Alkenes and aromatics contributed 63.0% and 29.2% to OFP values which derived from PIC of each VOC species. The relative incremental reactivity analysis based on PICs showed that the O3 formation was controlled by the cooperation of nitrogen oxides (NOx) and VOCs, and the effect of NOx emission reduction was better.
6
Xue, Yonggang, Yu Huang, Steven Sai Hang Ho, Long Chen, Liqin Wang, Shuncheng Lee e Junji Cao. "Origin and transformation of ambient volatile organic compounds during a dust-to-haze episode in northwest China". Atmospheric Chemistry and Physics 20, n. 9 (8 maggio 2020): 5425–36. http://dx.doi.org/10.5194/acp-20-5425-2020.
Testo completoAbstract (sommario):
Abstract. The high contribution of secondary organic aerosol to the loading of fine particle pollution in China highlights the roles of volatile organic compound (VOC) oxidation. In this respect, particulate active metallic oxides in dust, like TiO2 and Fe ions, were proposed to influence the photochemical reactions of ambient VOCs. A case study was conducted at an urban site in Xi'an, northwest China, to investigate the origin and transformation of VOCs during a windblown dust-to-haze pollution episode, and the assumption that dust would enhance the oxidation of VOCs was verified. Local vehicle exhaust (25 %) and biomass burning (18 %) were found to be the two largest contributors to ambient VOCs. In the dust pollution period, a sharp decrease in the loading of VOCs and the aging of their components were observed. Simultaneously, the secondary oxygenated VOC fraction (i.e., methylglyoxal) increased. Source strength, physical dispersion, and regional transport were eliminated as major factors for the variation of ambient VOCs. In another aspect, about a 2- to 3-fold increase in the loading of iron (Fe) and titanium (Ti) was found in the airborne particles, together with a fast decrease in trans-/cis-2-butene ratios, which demonstrated that dust can accelerate the oxidation of ambient VOCs and the formation of secondary organic aerosol (SOA) precursors.
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Vanderplanck, Maryse, Benoît Lapeyre, Margot Brondani, Manon Opsommer, Mathilde Dufay, Martine Hossaert-McKey e Magali Proffit. "Ozone Pollution Alters Olfaction and Behavior of Pollinators". Antioxidants 10, n. 5 (21 aprile 2021): 636. http://dx.doi.org/10.3390/antiox10050636.
Testo completoAbstract (sommario):
Concentration of air pollutants, particularly ozone (O3), has dramatically increased since pre-industrial times in the troposphere. Due to the strong oxidative potential of O3, negative effects on both emission and lifetime in the atmosphere of plant volatile organic compounds (VOCs) have already been highlighted. VOCs alteration by O3 may potentially affect the attraction of pollinators that rely on these chemical signals. Surprisingly, direct effects of O3 on the olfaction and the behavioral response of pollinators have not been investigated so far. We developed a comprehensive experiment under controlled conditions to assess O3 physiological and behavioral effects on two pollinator species, differing in their ecological traits. Using several realistic concentrations of O3 and various exposure times, we investigated the odor antennal detection and the attraction to VOCs present in the floral scents of their associated plants. Our results showed, in both species, a clear effect of exposure to high O3 concentrations on the ability to detect and react to the floral VOCs. These effects depend on the VOC tested and its concentration, and the O3 exposure (concentration and duration) on the pollinator species. Pollination systems may, therefore, be impaired in different ways by increased levels of O3, the effects of which will likely depend on whether the exposure is chronic or, as in this study, punctual, likely causing some pollination systems to be more vulnerable than others. While several studies have already shown the negative impact of O3 on VOCs emission and lifetime in the atmosphere, this study reveals, for the first time, that this impact alters the pollinator detection and behavior. These findings highlight the urgent need to consider air pollution when evaluating threats to pollinators.
8
Cordell, Rebecca L., Rikesh Panchal, Emmanuel Bernard, Michael Gatari, Ezekiel Waiguru, Moses Ng’ang’a, James Nyang’aya et al. "Volatile Organic Compound Composition of Urban Air in Nairobi, Kenya and Lagos, Nigeria". Atmosphere 12, n. 10 (12 ottobre 2021): 1329. http://dx.doi.org/10.3390/atmos12101329.
Testo completoAbstract (sommario):
Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and Nairobi growing at a rate of 3–4% a year. The region is extremely under-sampled for all air pollutants, particularly VOCs, which are useful markers for source apportionment as well as toxic in their own right. There are many contributors to air pollution in the region, and studies examining fine particulate pollution implicate traffic as the primary source in urban areas. In this pilot study, VOCs were analysed at a selection of roadside and urban background locations in Nairobi and Lagos, and 74 VOCs were quantified. GC×GC–MS/FID analysis revealed all locations were dominated by hydrocarbons typical of vehicle emissions, with the aromatic hydrocarbons benzene and toluene among the most abundant VOCs. Typical personal exposure scenarios for citizens of the cities were calculated to far exceed those of a resident in a city in Europe/US. Finally, the calculated ozone forming potential of the VOCs measured was found to be similarly high to other large cities studied with similar air pollution problems. Further study is therefore essential to determine the full extent of VOC pollution in the region and its impact on tropospheric chemistry.
9
Alvarez-Vaca, Daniel, Radu Corneliu Duca, Alicia Borras-Santos, Emilie Hardy, Matteo Creta, Carole Eicher, Laurence Wurth, Anne Vergison e An Van Nieuwenhuyse. "Surveillance of Indoor Air Concentration of Volatile Organic Compounds in Luxembourgish Households". International Journal of Environmental Research and Public Health 19, n. 9 (30 aprile 2022): 5467. http://dx.doi.org/10.3390/ijerph19095467.
Testo completoAbstract (sommario):
Exposure to air pollution is a well-known health risk. For instance, volatile and very volatile organic compounds (VOCs and VVOCs) are known to cause respiratory, haematologic or immune diseases, and even cancer. Based on the Luxembourgish indoor pollution surveillance program, we performed an exploratory analysis for the period 2014–2019, in order (1) to evaluate the prevalence of VOCs and VVOCs in households, and (2) to estimate the risks of lifelong exposure to selected VOCs on the health of the adult population. The database included 715 indoor air samples from 159 different households. Observed VOC and VVOC levels were similar to those in neighbouring countries. Our health impact assessment identified some health risks associated with the observed concentrations in Luxembourg. Furthermore, this study shows the major public health importance of having a national indoor pollution surveillance system in place. Highlights: (1) This study provides an overview of the domestic indoor pollution in Luxembourg. (2) (V)VOCs levels in Luxembourg were similar to those in neighbouring countries. (3) The results clearly show the importance of having a surveillance system in place.
10
Du, Zhao, Xiang Ling Yuan, Ai Ling Ren e Feng Ying Fu. "Typical Pharmaceutical Process VOCs and Stench Pollution Characteristics and Control Techniques". Advanced Materials Research 726-731 (agosto 2013): 2017–21. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.2017.
Testo completoAbstract (sommario):
According to the pharmaceutical industry produce VOCs and stench of atmospheric environment pollution, combined with typical pharmaceutical biological fermentation and chemical synthesis process of VOCs and odour pollution are classified 4 types:fermentation tail gas, recycling of exhaust gas, exhaust gas and wastewater workshop stench. The control technology should be selected according to the four types of waste characteristics.
11
Tan, Rui, Song Guo, Sihua Lu, Hui Wang, Wenfei Zhu, Ying Yu, Rongzhi Tang et al. "Characteristics and Secondary Organic Aerosol Formation of Volatile Organic Compounds from Vehicle and Cooking Emissions". Atmosphere 14, n. 5 (28 aprile 2023): 806. http://dx.doi.org/10.3390/atmos14050806.
Testo completoAbstract (sommario):
In the present work, volatile organic compounds (VOCs) from vehicle exhaust and cooking fumes were investigated via simulation experiments, which covered engine emissions produced during gasoline direct injection (GDI) using two kinds of fuels and cooking emissions produced by preparing three domestic dishes. The distinct characteristics of VOCs emitted during the two processes were identified. Alkanes (73% mass fraction on average) and aromatics (15% on average) dominated the vehicle VOCs, while oxygenated VOCs (49%) and alkanes (29%) dominated the cooking VOCs. Isopentane (22%) was the most abundant species among the vehicle VOCs. N-hexanal (20%) dominated the cooking VOCs. The n-hexanal-to-n-pentanal ratio (3.68 ± 0.64) was utilized to identify cooking VOCs in ambient air. The ozone formation potential produced by cooking VOCs was from 1.39 to 1.93 times higher than that produced by vehicle VOCs, which indicates the significant potential contribution of cooking VOCs to atmospheric ozone. With the equivalent photochemical age increasing from 0 h to 72 h, the secondary organic aerosol formation by vehicle VOCs was from 3% to 38% higher than that of cooking VOCs. Controlling cooking emissions can reduce SOA pollution in a short time due to its higher SOA formation rate than that of vehicle VOCs within the first 30 h. However, after 30 h of oxidation, the amount of SOAs formed by vehicle exhaust emissions exceeded the amount of SOAs produced by cooking activities, implying that reducing vehicle emissions will benefit particle pollution for a longer time. Our results highlight the importance of VOCs produced by cooking fumes, which has not been given much attention before. Further, our study suggested that more research on semi-volatile organic compounds produced by cooking emissions should be conducted in the future.
12
Han, Meng, Jing Geng, Gen Wang, Jian Zhuang Wang, Ying Hui Liu, Yuan Gang Wang e Tie Zheng Wang. "Source Apportionment of VOCs in Urban Tianjin, China". Advanced Materials Research 955-959 (giugno 2014): 1326–29. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.1326.
Testo completoAbstract (sommario):
facing the problem of VOCs pollution, VOCs concentrations in urban Tianjin have been measured to identify their possible sources. Using positive matrix factorization, seven VOC sources are identified in urban Tianjin according to the factor loadings of various VOCs, including: 1) motor vehicle exhaust; 2) gasoline evaporation; 3) internal engine combustion emission; 4) diesel emission; 5) solvent usage; 6) industrial emission; and 7) biogenic emission. The identified sources of VOCs are significantly related to vehicular activities, which specifically contribute 60% to VOCs loadings in urban Tianjin, respectively. Controlling vehicle emissions should be top priority for VOCs reduction in Tianjin.
13
Shellaiah, Muthaiah, e Kien Wen Sun. "Inorganic-Diverse Nanostructured Materials for Volatile Organic Compound Sensing". Sensors 21, n. 2 (18 gennaio 2021): 633. http://dx.doi.org/10.3390/s21020633.
Testo completoAbstract (sommario):
Environmental pollution related to volatile organic compounds (VOCs) has become a global issue which attracts intensive work towards their controlling and monitoring. To this direction various regulations and research towards VOCs detection have been laid down and conducted by many countries. Distinct devices are proposed to monitor the VOCs pollution. Among them, chemiresistor devices comprised of inorganic-semiconducting materials with diverse nanostructures are most attractive because they are cost-effective and eco-friendly. These diverse nanostructured materials-based devices are usually made up of nanoparticles, nanowires/rods, nanocrystals, nanotubes, nanocages, nanocubes, nanocomposites, etc. They can be employed in monitoring the VOCs present in the reliable sources. This review outlines the device-based VOC detection using diverse semiconducting-nanostructured materials and covers more than 340 references that have been published since 2016.
14
Yu, Hui, Qianqian Liu, Nana Wei, Mingfeng Hu, Xuezhe Xu, Shuo Wang, Jiacheng Zhou, Weixiong Zhao e Weijun Zhang. "Investigation of Summertime Ozone Formation and Sources of Volatile Organic Compounds in the Suburb Area of Hefei: A Case Study of 2020". Atmosphere 14, n. 4 (19 aprile 2023): 740. http://dx.doi.org/10.3390/atmos14040740.
Testo completoAbstract (sommario):
Ground surface ozone (O3) is an emerging concern in China due to its complex formation process. In August 2020, field measurements of O3, NOx, and volatile organic compounds (VOCs) were carried out in Hefei’s western suburbs. The pollution features of VOCs and O3 formation were thoroughly analyzed. The total VOC concentration was 42.26 ppb, with the dominant contributor being oxygenated VOCs (OVOCs). Seven emission sources were recognized using the positive matrix factorization (PMF) model, including aged air masses, combustion sources, fuel evaporation, industrial emissions, vehicular emission, solvent utilization, and biogenic emission. Ozone generation mainly occurred under an NOx-limited regime based on the zero-dimensional box model analysis. According to the scenario analysis, the 13% cut in O3 might be achieved by the 10% and 30% reduction in NOx and VOCs, respectively. The O3 budget analysis demonstrates its high ozone production rate during the pollution period. The influence of regional transport cannot be ignored for high O3 pollution. This paper provides scientific evidence for O3 production and the strategies of reducing O3 by controlling its precursors.
15
Yao, Shiyin, Wei Wei, Shuiyuan Cheng, Yuan Niu e Panbo Guan. "Impacts of Meteorology and Emissions on O3 Pollution during 2013–2018 and Corresponding Control Strategy for a Typical Industrial City of China". Atmosphere 12, n. 5 (12 maggio 2021): 619. http://dx.doi.org/10.3390/atmos12050619.
Testo completoAbstract (sommario):
The air quality of Handan, a typical industrial city in China, has been significantly improved through atmospheric pollution control, except for ozone (O3) pollution. We found that, in summer, emissions of anthropogenic volatile organic compounds (VOCs) and NOx decreased yearly in Handan, but the O3 concentration significantly declined yearly during 2013–2015, whereas it experienced worsening O3 pollution after 2015. Therefore, we used the Weather Research and Forecasting Community Multiscale Air Quality (WRF–CMAQ) modeling system to simulate the influence of the meteorological conditions and emission changes in Handan during the typical period (June) of O3 pollution in 2013–2018. For benchmarked June 2013, the results showed that the reduction of the O3 concentration in June of 2014–2016 was mainly caused by emission reduction, while in June of 2017–2018, the combined effect of changes in emissions and meteorological conditions led to aggravated O3 pollution. Sensitivity analysis indicated that combined VOCs and NOx emission controls would effectively reduce incremental O3 formation when the abatement ratio of VOCs/NOx should be no less than 0.84, and we found that VOCs reduction would continusouly bring about O3 decreases under various NOx reductions, but its positive sensitivity to O3 would become smaller with NOx reduction. However, the positive influence of NOx reduction on O3 would happen until NOx reduction exceeding 45–60%. The findings will be helpful in formulating emission control strategies for coping with O3 pollution in an industrial city.
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Sakunkoo, Pornpun, Saksit Phonphinyo, Naowarat Maneenin, Chananya Jirapornkul, Yuparat Limmongkon, Jetnapis Rayubkul, Sakesun Thongtip e Sarawut Sangkham. "Comparison of Volatile Organic Compound Concentrations in Ambient Air among Different Source Areas around Khon Kaen, Thailand". Atmosphere 12, n. 12 (17 dicembre 2021): 1694. http://dx.doi.org/10.3390/atmos12121694.
Testo completoAbstract (sommario):
Volatile organic compounds (VOCs) are a complex group of chemicals that pose a direct risk to human health. They also lead to the formation of other air pollution constituents, including fine particulate matter (PM2.5) and ground level ozone (O₃). The ambient air concentrations of 19 VOCs were measured using multi-day 24 h sampling at two urban sites and two rural sites in the area of Khon Kaen, Thailand. Results showed that most VOCs were at concentrations considered acceptable according to the 24 h average standards established by the Thai Pollution Control Department. The VOC acrolein, however, was detected at concentrations (0.69–1.15 μg/m3) in excess of the 24 h average standard (0.55 μg/m3). Two other VOCs, benzene and 1,3-butadiene, were also detected at elevated levels (1.73–2.75 and 0.18–0.40 μg/m3, respectively) that indicated the potential to exceed the 1-year average standard. VOC concentrations were highest in the urban market monitoring site, suggesting that vehicle exhaust and food preparation using cooking oil at high temperatures may have been potential sources of the elevated VOCs.
17
Yu, Jian Feng, Qing Cui, Yun Hui Du, Fan Chen e Cun Wei Zhan. "Strategies to Control VOCs Emissions from the Petroleum Storage and Transportation Project in Chinese Ports". Advanced Materials Research 955-959 (giugno 2014): 1747–49. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.1747.
Testo completoAbstract (sommario):
This paper summarized the characteristics and status of VOCs pollution of the harbour petroleum storage project, learnt from the regulation policy and prevention technique of developed countries for controlling VOCs emission from the harbours oil product storage and transportation system, and then put forward suggestions for preventing and controlling VOCs from the oil product storage and transportation projects in Chinese port by considering the requirements of "MARPOL73/78".
18
Yang, Xi, Xuwei Deng, Guangxin Li, Yu Liu e Qiang Gao. "Human Activities Aggravate VOC Pollution in the Huangshui River of the Tibetan Plateau". Sustainability 14, n. 19 (22 settembre 2022): 11983. http://dx.doi.org/10.3390/su141911983.
Testo completoAbstract (sommario):
Many xenobiotic compounds can threaten human health and natural ecosystems. The ability to predict the level of human activities and identify major impact factors is crucial for the design of pollutant risk-reduction plans. In this study, a total of 25 volatile organic compounds (VOCs) including eight alkenes, six alkanes, and eleven aromatics were identified at 11 monitoring locations along the Huangshui River of the Tibetan Plateau. GC-MS analysis was applied to detect the concentrations of the VOCs. The results showed that the alkene, alkane, and aromatic concentrations in the sediment were significantly higher than in the water in all seasons (p < 0.001). The VOC concentrations in summer were significantly higher than in spring and winter (p < 0.01). In addition, several VOCs were found to surpass the national standard, i.e., bromoform reached 312.43 μg/L in water during the summer (the national standard is 100 μg/L), carbon tetrachloride was 209.58 μg/L (the national standard is 2 μg/L), and vinyl chloride was 10.99 μg/L (the national standard is 5 μg/L), which were all related to human activities. Principal component analysis (PCA) was used to comprehensively evaluate the water quality and the VOCs. The total organic carbon (TOC) was found to be responsible for the presence of the VOCs in the river, accounting for 77.93%, 81.97%, and 82.13% of the total variance in the datasets in spring, summer, and winter, respectively.
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Kong, Lan, Tianzhi Luo, Xia Jiang, Shuhua Zhou, Gang Huang, Dongyang Chen, Yuting Lan e Fumo Yang. "Seasonal Variation Characteristics of VOCs and Their Influences on Secondary Pollutants in Yibin, Southwest China". Atmosphere 13, n. 9 (30 agosto 2022): 1389. http://dx.doi.org/10.3390/atmos13091389.
Testo completoAbstract (sommario):
Volatile organic compounds (VOCs) have a crucial impact on the formation of ozone and secondary organic aerosols in the near-surface atmosphere. Understanding the composition characteristics and sources of VOCs is necessary for determining effective control policies to mitigate VOCs and related secondary pollutions. We performed on-line measurements of VOC species in typical months of each season in Yibin, a fast-growing city in Sichuan Basin in China, to identify VOC seasonal characteristics, sources, and the potential for secondary pollution formation. The average mixing ratio of VOCs in Yibin was 22.3 ppbv. Five major emission sources were identified through the positive matrix factorization model, namely, gasoline vehicle, diesel vehicle, industrial manufacturing, solvent utilization, regional background, and secondary formation. Aromatics and alkenes played leading roles in the secondary formation of ozone and secondary organic aerosols. Furthermore, m/p-xylene, ethylene, and toluene were identified to be the major reactive species. Future management should consider targeting these compounds when evaluating ozone and aerosol reduction strategies. Vehicle and solvent utilization emission mitigation would be the primary and effective ways to improve air quality in the fast-developing city in this region.
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Zhang, Chenyue, Shuzhen Luo, Wenting Zhao, Yuntao Wang, Qiang Zhang, Chengkai Qu, Xingang Liu e Xiaoyu Wen. "Impacts of Meteorological Factors, VOCs Emissions and Inter-Regional Transport on Summer Ozone Pollution in Yuncheng". Atmosphere 12, n. 12 (10 dicembre 2021): 1661. http://dx.doi.org/10.3390/atmos12121661.
Testo completoAbstract (sommario):
Summer ozone (O3) pollution in China has become increasingly serious in recent years. This study is based on hourly data of near-surface ozone (O3) and nitrogen oxides (NOx) and volatile organic compounds (VOCs) from June to August 2020 in Yuncheng, combined with meteorological data to analyse the characteristics of O3 pollution in summer and the influence of meteorological factors, precursors, and long-range transport on O3 pollution. In this paper, the VOCs/NOx characteristic ratio method was used to explore the sensitivity of O3 generation. Backward trajectories, cluster analysis, potential source contribution factor (PSCF) analysis and concentration weight trajectory (CWT) analysis were also calculated using Trajstat software. In 2020, Yuncheng had persistent O3 pollution, with the highest concentrations in June, significantly higher than July and August. Conditions of high temperature, low relative humidity and low wind speed contribute to the O3 accumulation. VOCs are the main precursors to the local production of O3. Besides, the long-range transport analysis shows that southeast-oriented air masses are the main direction influencing summer O3 pollution. The primary potential source areas of O3 are in the central and southern part of Henan province, the north-western Anhui province, and the northern Shaanxi. In addition, northern Hubei and southwestern Shandong also influence O3 pollution in summer Yuncheng.
21
Li, Bowei, Steven Sai Hang Ho, Sunling Gong, Jingwei Ni, Huairui Li, Liyan Han, Yi Yang, Yijin Qi e Dongxu Zhao. "Characterization of VOCs and their related atmospheric processes in a central Chinese city during severe ozone pollution periods". Atmospheric Chemistry and Physics 19, n. 1 (16 gennaio 2019): 617–38. http://dx.doi.org/10.5194/acp-19-617-2019.
Testo completoAbstract (sommario):
Abstract. A 5-month campaign (from May to September 2017) was conducted to characterize volatile organic compounds (VOCs) for the first time at four sites in Zhengzhou, Henan Province, China, where ground level ozone (O3) concentration has shown an increasing trend in recent years. Canister samples were collected for the measurement of 57 VOCs, which, along with reactive nitrogen oxides (NOx), are the most important O3 precursors. During the same period, O3 and its precursor gases were monitored online simultaneously. The results indicated that the average mixing ratio of total quantified VOCs (ΣVOCs=28.8±22.1 ppbv) in Zhengzhou was lower than that in the other Chinese megacities, while alkyne comprised a higher proportion of ΣVOCs. The abundances, compositions and ratios of typical VOCs showed clear spatial and temporal variations. Cluster analysis indicates that air masses from the south of Zhengzhou were cleaner than from other directions. The molar ratio of VOCs to NOx indicated that, in general, O3 formation was more sensitive to VOCs than NOx formation in Zhengzhou. The source apportionment was conducted with positive matrix factorization (PMF), and it was found that vehicle exhaust, coal and biomass burning and solvent usage were the major sources for ambient VOCs at all four sites. From potential source contribution function (PSCF) analysis, the strong emissions from coal + biomass burning and solvent usage were concentrated in the southwest of Shanxi and Henan provinces. This study gathers scientific evidence on the pollution sources for Zhengzhou, benefiting the government to establish efficient environmental control measures, particularly for O3 pollution.
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Shi, Jianwu, Yuzhai Bao, Feng Xiang, Zhijun Wang, Liang Ren, Xiaochen Pang, Jian Wang, Xinyu Han e Ping Ning. "Pollution Characteristics and Health Risk Assessment of VOCs in Jinghong". Atmosphere 13, n. 4 (11 aprile 2022): 613. http://dx.doi.org/10.3390/atmos13040613.
Testo completoAbstract (sommario):
In order to investigate the seasonal variation in chemical characteristics of VOCs in the urban and suburban areas of southwest China, we used SUMMA canister sampling in Jinghong city from October 2016 to June 2017. Forty-eight VOC species concentrations were analyzed using atmospheric preconcentration gas chromatography–mass spectrometry (GC–MS), Then, regional VOC pollution characteristics, ozone formation potentials (OFP), source identity, and health risk assessments were studied. The results showed that the average concentration of total mass was 144.34 μg·m−3 in the urban area and 47.81 μg·m−3 in the suburban area. Alkanes accounted for the highest proportion of VOC groups at 38.11%, followed by olefins (36.60%) and aromatic hydrocarbons (25.28%). Propane and isoprene were the species with the highest mass concentrations in urban and suburban sampling sites. The calculation of OFP showed that the contributions of olefins and aromatic hydrocarbons were higher than those of alkanes. Through the ratio of specific species, the VOCs were mainly affected by motor vehicle exhaust emissions, fuel volatilization, vegetation emissions, and biomass combustion. Combined with the analysis of the backward trajectory model, biomass burning activities in Myanmar influenced the concentration of VOCs in Jinghong. Health risk assessments have shown that the noncarcinogenic risk and hazard index of atmospheric VOCs in Jinghong were low (less than 1). However, the value of the benzene cancer risk to the human body was higher than the safety threshold of 1 × 10−6, showing that benzene has carcinogenic risk. This study provides effective support for local governments formulating air pollution control policies.
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Chen, Tianshu, Likun Xue, Penggang Zheng, Yingnan Zhang, Yuhong Liu, Jingjing Sun, Guangxuan Han et al. "Volatile organic compounds and ozone air pollution in an oil production region in northern China". Atmospheric Chemistry and Physics 20, n. 11 (15 giugno 2020): 7069–86. http://dx.doi.org/10.5194/acp-20-7069-2020.
Testo completoAbstract (sommario):
Abstract. Oil and natural gas (O&NG) exploration presents a significant source of atmospheric volatile organic compounds (VOCs), which are central players of tropospheric chemistry and contribute to formations of ozone (O3) and secondary organic aerosols. The impacts of O&NG extraction on regional air quality have been investigated in recent years in North America, but have long been overlooked in China. To assess the impacts of O&NG exploration on tropospheric O3 and regional air quality in China, intensive field observations were conducted during February–March and June–July 2017 in the Yellow River delta, an oil extraction region in northern China. Very high concentrations of ambient VOCs were observed at a rural site, with the highest alkane mixing ratios reaching 2498 ppbv. High-O3 episodes were not encountered during wintertime but were frequently observed in summer. The emission profiles of VOCs from the oil fields were directly measured for the first time in China. The chemical budgets of ROx radicals and O3 were dissected with a detailed chemical box model constrained by in situ observations. The highly abundant VOCs facilitated strong atmospheric oxidation capacity and O3 formation in the region. Oxygenated VOCs (OVOCs) played an essential role in the ROx primary production, OH loss, and radical recycling. Photolysis of OVOCs, O3, and HONO as well as ozonolysis reactions of unsaturated VOCs were major primary sources of ROx. NOx was the limiting factor of radical recycling and O3 formation. This study underlines the important impacts of O&NG extraction on atmospheric chemistry and regional air quality in China.
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Kang, Ningxin, Weichuang Zhou, Zheng Qi, Yuhan Li, Zhi Wang, Qin Li e Kangle Lv. "Recent Progress of Natural Mineral Materials in Environmental Remediation". Catalysts 12, n. 9 (4 settembre 2022): 996. http://dx.doi.org/10.3390/catal12090996.
Testo completoAbstract (sommario):
Organic contaminants, volatile organic compounds (VOCs), and heavy metals have posed long-term threats to the ecosystem and human health. Natural minerals have aroused widespread interest in the field of environmental remediation due to their unique characteristics such as rich resources, environmentally benign, and excellent photoelectric properties. This review briefly introduced the contributions of natural minerals such as sulfide minerals, oxide minerals, and oxysalt minerals in pollution control, which include organic pollution degradation, sterilization, air purification (NO VOCs oxidation), and heavy metal treatment by means of photocatalysis, Fenton catalysis, persulfate activation, and adsorption process. At last, the future challenges of natural mineral materials in pollution control are also outlooked.
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Yuan, Hua Wei, Hong Ling Yin, Yun Huang, Shu Qian, Zhen Wei Xie, Qin Kai Su e Qing Qin. "Study on the Pollution Characteristic of VOCs in Ambient Air of Chengdu". Advanced Materials Research 610-613 (dicembre 2012): 1889–94. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1889.
Testo completoAbstract (sommario):
In this study, the environmental behavior of major VOCs in ambient air were investigated in urban and suburban areas in Chengdu city in the spring of 2012. VOCs samples were collected by sorbent tubes with TENAX TA, and were analyzed by thermal desorption followed by gas chromatography mass spectrometry. The most abundant VOCs were aromatic hydrocarbons (58.09%), next in order were alkanes(15.28%), esters(11.27%), aldehydes and ketones(7.64%), acids and heterocyclic compounds(3.39%), olefins(2.96%), alcohols(0.84%), amines(0.35%), ethers(0.17%). Alkanes, alkenes, aromatic hydrocarbons, esters and alcohols had the similar diurnal variation, and their concentration peaks appeared in the morning 08-09; ethers, aldehydes and ketones had similar characteristics of diurnal variation, and their concentration peaks occurred in the afternoon 14-15. This paper provided an overview and some useful information for approaching the composition characteristics, concentration levels and variation in ambient air of Chengdu
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Zhang, Yuxiu, Tingting Zang, Bo Yan e Chaohai Wei. "Distribution Characteristics of Volatile Organic Compounds and Contribution to Ozone Formation in a Coking Wastewater Treatment Plant". International Journal of Environmental Research and Public Health 17, n. 2 (15 gennaio 2020): 553. http://dx.doi.org/10.3390/ijerph17020553.
Testo completoAbstract (sommario):
Ozone pollution, which can be caused by photochemical reactions, has become a serious problem. The ozone formation potential (OFP) is used to describe the photochemical reactivity. Volatile organic compounds (VOCs) are main precursors of ozone formation, and wastewater treatment plants (WWTPs) are important sources of VOCs. Therefore, it is necessary to study the concentration level and OFP of VOCs from WWTPs. In this work, a coking WWTP with anaerobic-oxic-oxic (A/O/O) processes in Shaoguan city, Guangdong province, China, was selected to investigate the characteristics of VOCs at wastewater treatment areas and office areas. The OFP of VOCs was estimated by the maximum incremental reactivity (MIR) coefficient method. Results showed that 17 VOCs were detected, and the total concentration of VOCs was the highest at the raw water tank (857.86 μg m−3). The benzene series accounted for 69.0%–86.9% and was the main component of VOCs in the WWTP. Based on OFP data, the top six VOCs contributing most to the OFP were m-xylene, toluene, p-xylene, o-xylene, styrene, and benzene. This study provides field data and information on the environmental risk of VOCs for coking companies and environmental departments. We found that the priority control sources of VOCs were wastewater treatment units because of their larger OFP contributions.
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Wu, Shu Yun, Zeng Feng Yan, Jun Gang Dong e Huan Huan Liu. "Research of the Distribution of Volatile Organic Compounds (VOC) in Print Shops in Xi’an". Applied Mechanics and Materials 209-211 (ottobre 2012): 1560–65. http://dx.doi.org/10.4028/www.scientific.net/amm.209-211.1560.
Testo completoAbstract (sommario):
Volatile organic compounds (VOCs) are major constituents of the indoor air pollutants. The indoor air quality has caused wide concern for VOCs may affect human health in many ways. The VOCs in general rooms volatilize from building materials, furniture and so on. In print shops the print equipment and materials may produce a large amount of VOCs that may affect the health of the long-term print shop workers. The author has measured the VOC content and the air indexes in a seventy square-meter print shop in Xi’an with comprehensive functions, then, evaluated the pollution and proposed the preventions of the VOC content in print shops.
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Li, Yan, e Bo Yan. "Human health risk assessment and distribution of VOCs in a chemical site, Weinan, China". Open Chemistry 20, n. 1 (1 gennaio 2022): 192–203. http://dx.doi.org/10.1515/chem-2022-0132.
Testo completoAbstract (sommario):
Abstract The study assessed the volatile organic compound (VOC) pollution characteristics in a chemical site in Weinan, China. The results indicated that chloroform, benzene, trichloroethylene, 1,2-dichloroethane, ethylbenzene, 1,2-dichloropropane, and 1,2,3-Trichloropropane exceeded the soil standard limit for soil contamination of development land (GB36600, PRC). Using pollution index, ambient severity, and correlation coefficient revealed industrial production and relocation activities as sources of VOCs contamination in the site. The carcinogenic risk assessed by human exposure to site VOCs through ingestion, respiration, exposure, etc., exceeded the potentially acceptable level (1.0 × 10−6). 1,2,3-trichloropropane has the highest carcinogenic risk across all pathways, regions, and populations. The long-term exposure and emission of VOCs in the investigated sites could likely pose an adverse health risk to site staff and the surrounding sensitive groups. Therefore, it is necessary to carry out strict investigation and evaluation of the site, and timely repair and control to protect the water, soil, and air environment and to avoid the long-term cumulative exposure risk to human health caused by VOCs emission.
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Cho, Arthur K., Yasuhiro Shinkai, Debra A. Schmitz, Emma Di Stefano, Arantza Eiguren-Fernandez, Aline Lefol Nani Guarieiro, Erika M. Salinas, John R. Froines e William P. Melega. "Chemical and Biological Characterization of Particulate Matter (PM 2.5) and Volatile Organic Compounds Collected at Different Sites in the Los Angeles Basin". Applied Sciences 10, n. 9 (7 maggio 2020): 3245. http://dx.doi.org/10.3390/app10093245.
Testo completoAbstract (sommario):
Background: Most studies on air pollution (AP) exposure have focused on adverse health effects of particulate matter (PM). Less well-studied are the actions of volatile organic compounds (VOCs) not retained in PM collections. These studies quantified chemical and biological properties of both PM2.5 and VOCs. Methods: Samples were collected near the Port of Los Angeles (Long Beach, LB), railroads (Commerce, CM), and a pollution-trapping topography-site (San Bernardino, SB). Quantitative assays were conducted: (1) chemical—prooxidant and electrophile content, (2) biological—tumor necrosis factor-α (TNF-α) and heme oxygenase-1 (HO-1) expression (3), VOC modulation of PM effects and (4), activation of the antioxidant response element (ARE) using murine RAW 264.7 macrophages. Results: SB site samples were the most potent in the chemical and biological assays, followed by a CM railroad site. Only PM2.5 exhibited significant proinflammatory responses. VOCs were more potent than PM2.5 in generating anti-inflammatory responses; further, VOC pretreatment reduced PM-associated TNF-α expression. VOCs significantly increased ARE activation compared to their corresponding PM2.5 which remained at background levels. Conclusion: Ambient VOCs are major contributors to adaptive responses that can modulate PM effects, in vitro, and, as such, need to be included in comprehensive assessments of AP.
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Ibragimova, Olga P., Anara Omarova, Bauyrzhan Bukenov, Aray Zhakupbekova e Nassiba Baimatova. "Seasonal and Spatial Variation of Volatile Organic Compounds in Ambient Air of Almaty City, Kazakhstan". Atmosphere 12, n. 12 (29 novembre 2021): 1592. http://dx.doi.org/10.3390/atmos12121592.
Testo completoAbstract (sommario):
Air pollution is one of the primary sources of risk to human health in the world. In this study, seasonal and spatial variations of multiple volatile organic compounds (VOCs) were measured at six sampling sites in Almaty, Kazakhstan. The seasonal and spatial variations of 19 VOCs were evaluated in 2020, including the periods before and after COVID-19 lockdown. The concentrations of 9 out of 19 VOCs had been changed significantly (p < 0.01) during 2020. The maximum concentrations of total VOCs (TVOCs) were observed on 15, 17, and 19 January and ranged from 233 to 420 µg m−3. The spatial distribution of TVOCs concentrations in the air during sampling seasons correlated with the elevation and increased from southern to northern part of Almaty, where Combined Heat and Power Plants are located. The sources of air pollution by VOCs were studied by correlations analysis and BTEX ratios. The ranges of toluene to benzene ratio and benzene, toluene, and ethylbenzene demonstrated two primary sources of BTEX in 2020: traffic emissions and biomass/biofuel/coal burning. Most of m-, p-xylenes to ethylbenzene ratios in this study were lower than 3 in all sampling periods, evidencing the presence of aged air masses at studied sampling sites from remote sources.
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Zhuang, Zhipeng, Weijian Zhou, Zhihua Pang, Yutao Lei e Wenzhong Liang. "Analysis on Comprehensive Treatment of VOCs in Key Industries of A City". E3S Web of Conferences 145 (2020): 02060. http://dx.doi.org/10.1051/e3sconf/202014502060.
Testo completoAbstract (sommario):
Vocs have become a weak base for air pollution control compared to particulate matter, sulfur dioxide and nitrogen oxide. Petrochemical, chemical, industrial coating, packaging and printing, oil storage and Marketing Industries (hereinafter referred to as key industries) are China’s key sources of VOCs emissions. In order to win the battle of protecting the blue sky and improve the air quality, it is urgent to strengthen the comprehensive treatment of VOCs in key industries. In order to fully understand the comprehensive treatment and emission control of industrial sources of organic waste gases in the city, an updated survey was conducted on the emission of VOCs from industrial sources in the region, and the results of the survey were analyzed Analysis report on VOCs emission and comprehensive treatment in key industries.
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Zhang, Yu-ting, Li-xin JIAO, Yun-xuan CHENG, Yue ZHANG, Yu-hua YIN e He HUANG. "Pollution Characteristics and Risk Assessment of Volatile Organic Compounds in Songhua Lake, China". International Journal of Scientific Research and Management 11, n. 03 (23 marzo 2023): 244–61. http://dx.doi.org/10.18535/ijsrm/v11i03.fe1.
Testo completoAbstract (sommario):
In order to assess the dangers to human health and the environment from Songhua Lake's volatile organic compounds (VOCs) pollution. A total of 18 VOCs were found in the water samples that were collected at 26 sampling locations in Songhua Lake utilizing the purge and trap technique and gas chromatography-mass spectrometry (GC-MS). Toluene and naphthalene had the highest detection rates among them, reaching 96.15%; trans-1,2-dichloroethylene, 1,2-dichloroethane, and isopropyl benzene had the lowest rates, only 3.85%. The maximum and average concentrations of 1,1-dichloroethane were 20.93 μg/L and 4.16 μg/L, respectively, the maximum concentration of isopropyl benzene was only 0.02 μg/L, and the average concentration was also the lowest. The spatial distribution of VOCs in Song Hua Lake was typically described as "high in the northwest and low in the southeast," with a concentration range of 0.00 to 23.21 μg/L. An examination of the current situation reveals that human activity-related ecological deterioration is the primary cause of the VOCs contamination in Songhua Lake. The results of the risk assessment revealed that there were only moderate ecological risks to aquatic organisms and that the non-carcinogenic and carcinogenic risk indices of Songhua Lake were within the safe range. Additionally, there were no non-carcinogenic or carcinogenic threats to the health of people as a whole.
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Yang, Xue, Luhong Gao, Shiyang Zhao, Guang Pan, Guolan Fan, Zhiyong Xia, Xiaoyan Sun, Hongyu Xu, Yanjun Chen e Xiaolong Jin. "Volatile Organic Compounds in the North China Plain: Characteristics, Sources, and Effects on Ozone Formation". Atmosphere 14, n. 2 (5 febbraio 2023): 318. http://dx.doi.org/10.3390/atmos14020318.
Testo completoAbstract (sommario):
Enhanced volatile organic compounds (VOCs) observations were made on ozone-exceeding days in June 2020 in Linyi, China. A total of 69 VOCs were collected (1 alkyne, 29 alkanes, 10 alkenes, 14 aromatic hydrocarbons, and 15 oxygenated volatile organic compounds (OVOCs)). The average concentration of total VOCs (TVOCs) was 36.0 ± 0.66 ppb, and the top three VOCs components were alkanes, OVOCs, and aromatic hydrocarbons, which accounted for 40.75%, 27.02%, and 11.30%, respectively. Based on the positive matrix factorization (PMF) model, the main sources of VOCs in Linyi City were divided into vehicle exhaust sources (39.11%), biomass combustion sources (21.82%), oil and gas volatilization sources (21.46%), and solvent use sources (17.61%). The ozone formation potential (OFP) contribution rate was dominated by alkenes, OVOCs, and aromatics, with contribution rates of 26.37%, 25.30%, and 23.65%, respectively. The top six VOCs that contributed the most to the OFP were formaldehyde, acetaldehyde, 1-butene, butadiene, trans-2-butene, and propylene. The empirical kinetic modelling approach (EKMA) curve indicated that the in situ ozone (O3) production was limited by VOCs, and reducing the concentration of O3 precursors in accordance with the VOCs/NOx concentration ratio of 1.15 can control O3 pollution more effectively.
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Wu, Edward Ming-Yang, e Shu-Lung Kuo. "Characteristics of Photochemical Reactions with VOCs Using Multivariate Statistical Techniques on Data from Photochemical Assessment Monitoring Stations". Atmosphere 13, n. 9 (13 settembre 2022): 1489. http://dx.doi.org/10.3390/atmos13091489.
Testo completoAbstract (sommario):
This study assesses the concentrations of the 54 ozone precursors (all being volatile organic compounds (VOCs)) detected at the four photochemical assessment monitoring stations that are part of the air quality monitoring network in the Kaohsiung-Pingtung area in Taiwan. Factor and cluster analyses of the multivariate statistical analysis are performed to explore the interrelationship among the 10 VOCs of relatively higher concentrations selected from the 54 ozone precursors to identify significant factors affecting ozone pollution levels in the study area. Moreover, the multivariate statistical analysis can faithfully reflect why the study area has been affected by photochemical pollution. First, results of the factor analysis suggest that the factors affecting how photochemical reactions occur in the study area can be divided into the following: “pollution from mobile sources”, “pollution from stationary sources”, and “pollution from energy sources”. Among them, mobile sources have the greatest impact on photochemical pollution levels. Second, the impacts of photochemical pollution on air quality in the study area can be classified into four clusters via cluster analysis. Each cluster represents how the 10 VOCs affect air quality, with different characteristics, and how they contribute to photochemical pollution in the study area. If there are more types and samples of photochemical pollutants when performing a multivariate statistical analysis, the analysis results will be more stable. This study adopts data on VOC monitoring over a period of nearly two years, which can effectively improve the validity and reliability of the factor analysis results, while helping environmental agencies review the effectiveness of air quality management in the future and serving as reference for the effectiveness of reducing photochemical pollution in the atmosphere.
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Haraslínová, Lucia. "Olfactometric pollution of air". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 57, n. 5 (2009): 111–18. http://dx.doi.org/10.11118/actaun200957050111.
Testo completoAbstract (sommario):
This paper describes the olfactometric assessment of volatile organic compounds emitted by coating films.It describes the measurements of concentration, intensity, hedonic tone and character of odor caused by emissions of volatile organic compounds. VOCs’ emitted in to the small-space chamber with capacity of 1 m3 were tested by dynamic olfactometric method. Paper also contains a comparison of olfactometric air pollution of two different types of coating films. The work is aimed to determine the relationships and dependencies between the measured values of volatile organic compounds obtained by the gas chromatography and reported sensation.
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Lu, Yang, Hai Wen Shu, Jing Liu e Lin Lin Li. "Research on Bake-Out with Dilution Ventilation for Indoor Air Pollution". Advanced Materials Research 518-523 (maggio 2012): 2749–52. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.2749.
Testo completoAbstract (sommario):
Bake-out exhaust method was used to significantly accelerate the release of VOCs from building materials. This paper studies the bake-out technology with dilution ventilation for indoor air pollution by experimental works. The baking effectiveness of formaldehyde, benzene, toluene and xylene ranged from 3 to 7.6, 7.6 to 25, 5.1 to 17 and 6 to 22 for the six cases, respectively. Baking effectiveness would become higher at longer baking time and higher baking temperature for formaldehyde and VOCs released from decorative materials. However, considering the possible deformation of building materials, 40°C and 10 hr would be the best choice for a suitable bake-out.
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Huang, Haibao, Ying Xu, Qiuyu Feng e Dennis Y. C. Leung. "Low temperature catalytic oxidation of volatile organic compounds: a review". Catalysis Science & Technology 5, n. 5 (2015): 2649–69. http://dx.doi.org/10.1039/c4cy01733a.
Testo completo
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Na Roi-et, Veerapas, e Supawat Chaikasem. "Potential of Passive Sampling and Plant Absorption to Quantify Inhalation Exposure to Volatile Organic Compounds". Environment and Natural Resources Journal 19, n. 1 (6 novembre 2020): 43–56. http://dx.doi.org/10.32526/ennrj/19/2020110.
Testo completoAbstract (sommario):
Emission of volatile organic compounds (VOCs) from photocopiers was investigated to assess the potential health impacts on inhalation exposure to VOCs. VOCs samples were collected during working hours using SKC VOCs 575 series passive sample. Twenty-one quantified VOCs were measured and analyzed by GC-MS/MS. The results showed that the total VOCs concentration emitted in the photocopy centers A and B were 2.29×104 and 2.32×104 µg/m3, respectively. The highest detected chemical was trans-1,2-Dichloroethene at about 2.18×104 (photocopy center A) and 2.15×104 µg/m3 (photocopy center B (The results reveal that the non-carcinogenic risk for inhalation exposure to m-Xylene, p-Xylene, and trans-1,2-Dichloroethene were in the range 0.94-1.53 and 1.19-1.79 and 51.54-52.23, respectively, resulting in the hazard index (HI) of non-carcinogenic VOCs in total being greater than 1.0. This indicated that the cumulative effects of inhalation exposure to VOCs at low concentrations should be of concern, even though it does not exceed the occupational exposure limits and Threshold Limit Values-Time Weighted Average for the mixtures (TLV-TWAmix). Plants display a greener solution to reduce indoor air pollution. The bio-concentration levels of total VOCs in Epipremnum aureum were noted as 74.71 to 174.42, signifying that E. aureum is effective for removal of VOCs naturally and sustainably.
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Wu, Zhenfeng, Yanli Zhang, Junjie He, Hongzhan Chen, Xueliang Huang, Yujun Wang, Xu Yu et al. "Dramatic increase in reactive volatile organic compound (VOC) emissions from ships at berth after implementing the fuel switch policy in the Pearl River Delta Emission Control Area". Atmospheric Chemistry and Physics 20, n. 4 (19 febbraio 2020): 1887–900. http://dx.doi.org/10.5194/acp-20-1887-2020.
Testo completoAbstract (sommario):
Abstract. Limiting fuel sulfur content (FSC) is a widely adopted approach for reducing ship emissions of sulfur dioxide (SO2) and particulate matter (PM), particularly in emission control areas (ECAs), but its impact on the emissions of volatile organic compounds (VOCs) is still not well understood. In this study, emissions from ships at berth in Guangzhou, southern China, were characterized before and after the implementation of the fuel switch policy (IFSP) with an FSC limit of 0.5 % in the Pearl River Delta ECA (ECA-PRD). After IFSP, the emission factors (EFs) of SO2 and PM2.5 for the coastal vessels decreased by 78 % and 56 % on average, respectively; however, the EFs of the VOCs were 1807±1746 mg kg−1, approximately 15 times that of 118±56.1 mg kg−1 before IFSP. This dramatic increase in the emissions of the VOCs might have been largely due to the replacement of high-sulfur residual fuel oil with low-sulfur diesel or heavy oils, which are typically richer in short-chain hydrocarbons. Moreover, reactive alkenes surpassed alkanes to become the dominant group among the VOCs, and low-carbon-number VOCs, such as ethylene, propene and isobutane, became the dominant species after IFSP. As a result of the largely elevated EFs of the reactive alkenes and aromatics after IFSP, the emitted VOCs per kilogram of fuel burned had nearly 29 times greater ozone formation potential (OFP) and approximately 2 times greater secondary organic aerosol formation potential (SOAFP) than those before IFSP. Unlike the coastal vessels, the river vessels in the region used diesel fuels consistently and were not affected by the fuel switch policy, but the EFs of their VOCs were 90 % greater than those of the coastal vessels after IFSP, with approximately 120 % greater fuel-based OFP and 70 %–140 % greater SOAFP. The results from this study suggest that while the fuel switch policy could effectively reduce SO2 and PM emissions, and thus help control PM2.5 pollution, it will also lead to greater emissions of reactive VOCs, which may threaten ozone pollution control in harbor cities. This change for coastal or ocean-going vessels, in addition to the large amounts of reactive VOCs from the river vessels, raises regulatory concerns for ship emissions of reactive VOCs.
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Yu, Shijie, Fangcheng Su, Shasha Yin, Shenbo Wang, Ruixin Xu, Bing He, Xiangge Fan, Minghao Yuan e Ruiqin Zhang. "Characterization of ambient volatile organic compounds, source apportionment, and the ozone–NO<sub>x</sub>–VOC sensitivities in a heavily polluted megacity of central China: effect of sporting events and emission reductions". Atmospheric Chemistry and Physics 21, n. 19 (13 ottobre 2021): 15239–57. http://dx.doi.org/10.5194/acp-21-15239-2021.
Testo completoAbstract (sommario):
Abstract. The implementation of strict emission control during the 11th National Minority Games (NMG) in September 2019 provided a valuable opportunity to assess the impact of such emission controls on the characteristics of VOCs and other air pollutants. Here, we investigated the characteristics of VOCs and the O3–NOx–VOC sensitivity comprehensively in Zhengzhou before, during, and after the NMG by delivering field measurements combined with WRF-CMAQ (Weather Research and Forecasting Community Multiscale Air Quality) model simulations. The average mixing ratios of VOCs during the control periods were 121 ± 55 µg m−3 and decreased by about 19 % and 11 % before and after emission reduction. The ozone precursors (NOx) also decreased significantly during the control period; however, the ozone pollution was severe during the entire observation period. Positive matrix factorization analysis indicated seven major sources of ambient VOCs, including coal combustion, biomass burning, vehicle exhausts, industrial processes, biogenic emissions, solvent utilization, and liquefied petroleum gas (LPG). The results show that the major source emissions, such as coal combustion and solvent utilization, were significantly reduced during the control period. As for ozone formation potential (OFP), the value during the control period was 183 ± 115 µg m−3, which was 0.23 and 0.17 times lower than before and after the control period, respectively. Solvent utilization and combustion controls were the most important measures taken to reduce OFP during the NMG period. Control policies can effectively reduce carcinogenic risk. However, non-cancer risks of ambient VOC exposures were all exceeding the safe level (hazard quotient = 1) during the sampling periods, and emphasis on the reduction of acrolein emissions was needed. In addition, the WRF-CMAQ model simulation indicated that O3 formation was controlled by VOCs in Zhengzhou. The results of the Empirical Kinetic Modeling Approach showed that the NOx reduction in Zhengzhou might lead to higher ozone pollution. It is suggested that reduction ratios of the precursors (VOCs : NOx) should be more than 2, which can effectively alleviate ozone pollution.
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Yin, Manfei, Xin Zhang, Yunfeng Li, Kai Fan, Hong Li, Rui Gao e Jinjuan Li. "Ambient ozone pollution at a coal chemical industry city in the border of Loess Plateau and Mu Us Desert: characteristics, sensitivity analysis and control strategies". PeerJ 9 (27 aprile 2021): e11322. http://dx.doi.org/10.7717/peerj.11322.
Testo completoAbstract (sommario):
In this study, ambient ozone (O3) pollution characteristics and sensitivity analysis were carried out in Yulin, a city in the central area of the Loess Plateau during 2017 to 2019 summer. O3 concentrations increased for 2017 to 2019. Correlation and statistics analysis indicated high temperature (T > 25 °C, low relative humidity (RH < 60%), and low wind speed (WS < 3 m/s) were favorable for O3 formation and accumulation, and the O3 pollution days (MDA8 O3 > 160 µg/m3) were predominantly observed when the wind was traveling from the easterly and southerly. O3 concentration in urban area of Yulin was higher than that in background. The pollution air masses from Fenwei Plain increase the level and duration of O3 pollution. In order to clarify the formation mechanism and source of O3, online measurements of volatile organic compounds (VOCs) were conducted from 7 July to 10 August in 2019. The average of VOCs concentration was 26 ± 12 ppbv, and large amounts of alkenes followed by aromatics, characteristic pollutants of the coal chemical industry, were detected in the ambient air. To further measure the sensitivity, the observation-based model (OBM) simulation was conducted. Empirical Kinetic Modeling Approach (EKMA) plot and relative incremental reactivity (RIR) value indicated Yulin located on VOCs-limited regime. That implied a slight decrease of NOx may increase O3 concentration. When the emission reduction ratio of anthropogenic VOCs/NOx higher than 1:1, the O3 will decrease. O3 control strategies analysis shows that the O3 targets of 5% and 10% O3 concentration reductions are achievable through precursor control, but more effort is needed to reach the 30% and 40% reduction control targets.
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Zhou, Bi’an, Tianyi Zhao, Jian Ma, Yuanxun Zhang, Lijia Zhang, Peng Huo e Yang Zhang. "Characterization of VOCs during Nonheating and Heating Periods in the Typical Suburban Area of Beijing, China: Sources and Health Assessment". Atmosphere 13, n. 4 (30 marzo 2022): 560. http://dx.doi.org/10.3390/atmos13040560.
Testo completoAbstract (sommario):
In recent years, the “coal to electricity” project (CTEP) using clean energy instead of coal for heating has been implemented by Beijing government to cope with air pollution. However, VOC pollution after CTEP was rarely studied in suburbs of Beijing. To fill this exigency, 116 volatile organic compounds (VOCs) were observed during nonheating (P1) and heating (P2) periods in suburban Beijing. The results showed that the total of VOCs (TVOCs) was positively correlated with PM2.5, PM10, NO2, CO, and SO2 but negatively correlated with O3 and wind speed. The average TVOCs concentration was 19.43 ± 12.41 ppbv in P1 and 16.25 ± 8.01 ppbv in P2. Aromatics and oxygenated VOCs (OVOCs) were the main contributors to ozone formation potential (OFP). Seven sources of VOCs identified by the positive matrix factorization (PMF) model were industrial source, coal combustion, fuel evaporation, gasoline vehicle exhaust, diesel vehicle exhaust, background and biogenic sources, and solvent usage. The contribution of coal combustion to VOCs increased significantly during P2, whereas industrial sources, fuel evaporation, and solvent usage exhibited opposite trends. The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used to analyze the source distributions. The results showed that VOC pollution was caused mainly by air mass from southern Hebei during P1 but by local emissions during P2. Therefore, although the contribution of coal combustion after heating increased, TVOCs concentration during P2 was lower than that during P1. Chronic noncarcinogenic risks of all selected VOC species were below the safe level, while the carcinogenic risks of most selected VOC species were above the acceptable risk level, especially for tetrachloromethane and 1,2-dichloroethane. The cancer risks posed by gasoline vehicle emissions, industrial enterprises, and coal combustion should be paid more attention.
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Lazar, Liliana, Ion Balasanian e Florin Bandrabur. "ENVIRONMENTAL POLLUTION WITH VOCs AND POSSIBILITIES FOR EMISSION TREATMENT". Environmental Engineering and Management Journal 6, n. 6 (2007): 529–35. http://dx.doi.org/10.30638/eemj.2007.066.
Testo completo
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Firoz Khan, Md, Mazrura Sahani, Mohd Shahrul Mohd Nadzir, Lin Chin Yik, Hossain Mohammad Syedul Hoque, Haris Hafizal Abd Hamid, Muhammad Ikram A. Wahab et al. "Volatile Organic Compound Analysis by Sorbent Tube-Thermal Desorption-Gas Chromatography: A Review". International Journal of Engineering & Technology 7, n. 3.14 (25 luglio 2018): 165. http://dx.doi.org/10.14419/ijet.v7i3.14.16878.
Testo completoAbstract (sommario):
Volatile organic compounds (VOCs) play an important role in the generation of ground level ozone and secondary organic aerosol. Most tropical countries such as Malaysia, Singapore, Indonesia, Brunei experience high ozone pollution. Beside ozone, oxides of nitrogen (NOx) from vehicular emissions also play an important role in photochemical pollution. NOx, particularly nitric oxide (NO), helps to ‘clean up’ ozone concentrations close to traffic in the ambient air of urban areas. Thus, knowledge of the chemistry of ozone-VOCs-NOx and finding the sources of VOCs are crucial to proceed with an appropriate mitigation strategy. Thus, the detection of ozone precursors and related VOCs is thoroughly discussed. This review finds that the inertness, hydrophobicity, and the effect of the artefact materials are very significant factors to be explored in the selection of the sorbent materials. In the SEA region, relative humidity is relatively high and exceeds 90% during the northeast monsoon. Thus, the hydrophobic properties of the sampling material need careful consideration. Further to the effect of relative humidity (RH), the artefact effect of the material itself is a challenge to be optimized and multi-sorbent material in a single tube could be a viable choice to minimize the effect of the unwanted signal in the spectrum.
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Qiu, Wanyi, Shule Li, Yuhan Liu e Keding Lu. "Petrochemical and Industrial Sources of Volatile Organic Compounds Analyzed via Regional Wind-Driven Network in Shanghai". Atmosphere 10, n. 12 (29 novembre 2019): 760. http://dx.doi.org/10.3390/atmos10120760.
Testo completoAbstract (sommario):
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.
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Kultan, Vanitchaya, Sarawut Thepanondh, Nattaporn Pinthong, Jutarat Keawboonchu e Mark Robson. "Comprehensive Evaluation of Odor-Causing VOCs from the Painting Process of the Automobile Manufacturing Industry and Its Sustainable Management". Atmosphere 13, n. 9 (16 settembre 2022): 1515. http://dx.doi.org/10.3390/atmos13091515.
Testo completoAbstract (sommario):
Automotive manufacturing is one of the potential sources of air pollution particularly involving volatile organic compounds (VOCs). This study intensively evaluated VOC emissions and their dispersion from the industry. The measured VOCs were speciated for further evaluation of their odor threats according to the characteristics of each compound. Mathematical emission and air dispersion models were applied to assist in elaborating the source–receptor relationship allowing the determining of existing business-as-usual conditions with proposed mitigation measures to manage the pollution of the factory studied in this paper. Seven VOC species potentially caused odor problems to the surrounding community, including 1-butanol, ethyl benzene, toluene, m,p xylene, o xylene, methyl ethyl ketone, and methyl isobutyl ketone. The results from the AERMOD dispersion model revealed that the smell from these chemicals could reach up to about 800 m from the source. Analysis of mitigation measures indicated that two interesting scenarios should be considered according to their effectiveness. The concentrations of VOCs can decrease by up to 4.7, 14.0 and 24.9% from increasing the physical stack height by +1, +3 and +5 m from its existing height, respectively. Modification of the aeration tank of the wastewater treatment unit to a closed system also helped to reduce about 27.8% of emissions resulting in about a 27.6% decreased ambient air concentration. This study provided useful information on the characteristics of VOCs emitted by the automobile manufacturing industry. It also demonstrated the relevant procedures and highlights the necessity to comprehensively analyze the source–receptor relationship to evaluate the most appropriate measures in managing industrial air pollution.
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Vasudha, Nannaparaju, e Polisetty Venkateswara Rao. "Factor Analysis of Air Pollutants over Hyderabad - A Case Study". Current World Environment 17, n. 2 (10 settembre 2022): 507–15. http://dx.doi.org/10.12944/cwe.17.2.21.
Testo completoAbstract (sommario):
Pollution levels in Metros of India are raising to alarm levels in last decades. This issue needs to be addressed immediately because it is hazardous to people's health. The present work is focused to highlight the major air pollutants in various areas of Hyderabad using publicly available data at Kaggle.com. By consolidating more air pollutants into fewer factors, this study's key objective is to reduce the complexity of air pollution. This helps to understand the interdependency of air pollutants. Ten air pollution-causing components of five different locations including residential and industrial areas in Hyderabad were identified and analyzed using Factor Analysis. There was an attempt made to find out the contribution of various air pollutant components to air pollution using standard Karl Pearson's coefficient of correlation and factor analysis using the Varimax method. The results of the analysis showed similar air pollutant components resulting in factors depending on the nature of the location. Residential cum industrial areas, ICRISAT and ZOO park had PM2.5, PM10, NOx, CO grouped into Factor 1 as major contribution to AQI, VOCs were the second major contributors followed by NH3, SO2, O3. However, in the residential area HCU ten air pollutants resulted into only two factors; first factor being CO, SO2, O3 and VOCs as contributors generated due to residential communities and PM2.5, PM10, NOx, NH3 as factor two. Bollaram has PM2.5, PM10, CO, O3 as factor one as major pollution is contributed due to traffic and industries and Pashamylaram has NOx, SO2 and VOCs as factor one due to the presence of pharmaceutical industries in the vicinity.
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JIA, JIA, Haibing Qiao, Guirong Li, Qiting Zuo e Weihong Yin. "EVOLUTION CHARACTERISTICS AND INFLUENCING FACTORS OF OZONE POLLUTION DURING LARGE-SCALE EVENTS". DYNA 97, n. 4 (1 luglio 2022): 425–31. http://dx.doi.org/10.6036/10520.
Testo completoAbstract (sommario):
The impact of temporary control measures on regional air quality during large-scale events is the focus of current research. Most of them focus on the discussion of environmental particulate matter concentration, while the changes in O3 concentration during such periods have not been explored. To reveal the variation characteristics of environmental O3 concentration during large-scale events, the ozone pollution control during the 2019 National Games in Zhengzhou, China was considered as an example and the six pollution parameters of state-controlled stations, meteorological parameters, and online volatile organic compound (VOC) component data was used. The evolution law of O3 pollution in Zhengzhou before and after the implementation of control measures was discussed, and the changes in NOx and the components of VOCs in different control stages were compared. The positive matrix factorization model was used to analyze the contribution of different types of pollution sources to the O3 mass concentration in Zhengzhou during the observation period. Results show that during the National Games, the concentration of O3 decreased by 45.2% and 29.3% compared with that before control and during Stage-I of control, respectively. The concentration of alkanes, olefins, and alkynes decreased significantly during the National Games, whereas the concentration of aromatic hydrocarbons increased by 6.5%. The pollution sources with the highest contribution of VOCs in Zhengzhou were as follows: motor vehicle tail gas source (the average contribution was 32.8%), natural gas/oil source (26.3%), solvent use source (20.4%), industrial process source (13.9%), and natural plant source (6.7%). The research conclusion revealed the evolution characteristics of O3 concentration and the causes of pollution during large-scale activities. Key Words: O3 pollution, VOCs, Control measures, the National Games, PMF source apportionment
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Crepaldi, R., G. M. Titato, F. M. Lanças, E. P. Sichieri, M. Telascrea e M. R. M. Chaves. "Assessment of Commercial Active Ceramic Tiles on Benzene Degradation for the Pollution Control of Indoor Atmospheric Buildings". Journal of Sustainable Development 10, n. 5 (29 settembre 2017): 257. http://dx.doi.org/10.5539/jsd.v10n5p257.
Testo completoAbstract (sommario):
Volatile Organic Compounds (VOCs) constitutes an important class of air pollutants, and benzene is one of the main contaminants of indoor air pollution. Among the methods for the treatment of environments with a high VOCs concentration is the photocatalytic oxidation by TiO2 (anatase) ceramic coated surfaces. The effectiveness of VOCs photodegradation studies using active ceramic tiles made in laboratory is well reported in the literature. However, this has not been reported using commercial tiles, although active ceramics are sold for such a function. In this context, this study proposed the assessment of commercial active ceramic tiles capacity in the photocatalytic degradation of benzene in indoor air. The development of this work arose from two questions: a) if the commercial active ceramic tiles are efficient in the VOCs degradation as the manufacturers claim; b) if they are able to degrade VOCs in indoor building environments. Experiments were conducted in laboratory’s scale, using an adapted simulation chamber. The volatilized benzene entered in contact with the commercial ceramic tile under fluorescent light and ultraviolet (UV) light of 365 nm. Samples of the chamber internal air were collected by adsorption on polydimethylsiloxane fibres in headspace technique (SPME-HS). The evaluation of the benzene degradation occurred by gas chromatography analysis with mass spectrometry (GC-MS). The characterization of commercial active ceramic samples occurred by techniques of X-Ray Diffraction Powder (XRD), and Scanning Electron Microscopy (SEM) with Energy Dispersive Spectrometry (EDS). Results showed that, under the experimental conditions, the commercial active ceramic tile was not capable of the benzene photocatalytic oxidation. The ceramic characterization detected very low quantity of TiO2 on ceramic samples, being this fact attributed as the main responsible for the ceramic photocatalytic inactiveness.
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Zhao, Qiuyue, Jun Bi, Qian Liu, Zhenghao Ling, Guofeng Shen, Feng Chen, Yuezhen Qiao, Chunyan Li e Zongwei Ma. "Sources of volatile organic compounds and policy implications for regional ozone pollution control in an urban location of Nanjing, East China". Atmospheric Chemistry and Physics 20, n. 6 (1 aprile 2020): 3905–19. http://dx.doi.org/10.5194/acp-20-3905-2020.
Testo completoAbstract (sommario):
Abstract. Understanding the composition, temporal variability and source apportionment of volatile organic compounds (VOCs) is necessary for determining effective control measures to minimize VOCs and their related photochemical pollution. To provide a comprehensive analysis of VOC sources and their contributions to ozone (O3) formation in the Yangtze River Delta (YRD) – a region experiencing the highest rates of industrial and economic development in China – we conducted a 1-year sampling exercise using a thermal desorption GC (gas chromatography) system for the first time at an urban site in Nanjing (JAES site). Alkanes were the dominant group at the JAES site, contributing ∼53 % to the observed total VOCs, followed by aromatics (∼17 %), acetylene (∼17 %) and alkenes (∼13 %). We identified seasonal variability in total VOCs (TVOCs) with maximum and minimum concentrations in winter and summer, respectively. Morning and evening peaks and a daytime trough were identified in the diurnal VOC patterns. We identified VOC sources using positive matrix factorization (PMF) and assessed their contributions to photochemical O3 formation by calculating the O3 formation potential (OFP) based on the mass concentrations and maximum incremental reactivities of VOCs. The PMF model identified five dominant VOC sources, with highest contributions from diesel vehicular exhaust (34±5 %), followed by gasoline vehicular exhaust (27±3 %), industrial emissions (19±2 %), fuel evaporation (15±2 %) and biogenic emissions (4±1 %). The results of the OFP calculation inferred that VOCs from industrial and vehicular emissions were found to be the dominant precursors for OFP, particularly the VOC species of xylenes, toluene and propene, and top priority should be given to these for the alleviation of photochemical smog. Our results therefore highlight that priority should be given to limited VOC sources and species for effective control of O3 formation in Nanjing.