Long-term Trends of Volatile Organic Compounds over the Texas, USA in the Past Two Decades

E3S Web of Conferences ◽

10.1051/e3sconf/202125901003 ◽

2021 ◽

Vol 259 ◽

pp. 01003

Author(s):

Ruizhe Liu

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Oil And Gas ◽

The Past ◽

Volatile Organic ◽

Long Term Trends ◽

Secondary Air Pollutants ◽

Secondary Air ◽

Oil And Gas Companies

Volatile organic compounds (VOCs) are organic compounds in the air that have low vapor pressure. VOCs can be emitted from a variety of sources including biogenic, anthropogenic and pyrogenic processes. VOCs are precursors of aerosols and tropospheric 03. which harm human health. However, the potential of VOCs forming secondary air pollutants varies by species. Here, we analyze the long-term trends of soiu'ce. concentration and reactivity of six classes of VOCs from 1995 to 2018 over Texas. USA. VOCs emission from petroleum and related companies in Texas kept increasing these years. Among the VOCs tracers of oil and gas companies, the concentration of ethane kept increasing until 2015. Despite the increase of oil and gas related VOCs. the concentration of total VOCs and reactivity-weighted VOCs have decreased in the past two decades. We further investigate the seasonality of VOC reactivities, which depend on both temperature and VOC concentration. We find that VOC reactivity generally is highest in fall and lowest in spring, and such seasonality does not change over the two decades.

Download Full-text

Long-term trends in air quality in major cities in the UK and India: a view from space

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-6275-2021 ◽

2021 ◽

Vol 21 (8) ◽

pp. 6275-6296

Author(s):

Karn Vohra ◽

Eloise A. Marais ◽

Shannen Suckra ◽

Louisa Kramer ◽

William J. Bloss ◽

...

Keyword(s):

Air Quality ◽

Volatile Organic Compounds ◽

Organic Compounds ◽

Temporal Consistency ◽

Ozone Monitoring Instrument ◽

Modis Aod ◽

Volatile Organic ◽

Long Term Trends ◽

The Uk

Abstract. Air quality networks in cities can be costly and inconsistent and typically monitor a few pollutants. Space-based instruments provide global coverage spanning more than a decade to determine trends in air quality, augmenting surface networks. Here we target cities in the UK (London and Birmingham) and India (Delhi and Kanpur) and use observations of nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI), ammonia (NH3) from the Infrared Atmospheric Sounding Interferometer (IASI), formaldehyde (HCHO) from OMI as a proxy for non-methane volatile organic compounds (NMVOCs), and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) for PM2.5. We assess the skill of these products at reproducing monthly variability in surface concentrations of air pollutants where available. We find temporal consistency between column and surface NO2 in cities in the UK and India (R = 0.5–0.7) and NH3 at two of three rural sites in the UK (R = 0.5–0.7) but not between AOD and surface PM2.5 (R < 0.4). MODIS AOD is consistent with AERONET at sites in the UK and India (R ≥ 0.8) and reproduces a significant decline in surface PM2.5 in London (2.7 % a−1) and Birmingham (3.7 % a−1) since 2009. We derive long-term trends in the four cities for 2005–2018 from OMI and MODIS and for 2008–2018 from IASI. Trends of all pollutants are positive in Delhi, suggesting no air quality improvements there, despite the roll-out of controls on industrial and transport sectors. Kanpur, identified by the WHO as the most polluted city in the world in 2018, experiences a significant and substantial (3.1 % a−1) increase in PM2.5. The decline of NO2, NH3, and PM2.5 in London and Birmingham is likely due in large part to emissions controls on vehicles. Trends are significant only for NO2 and PM2.5. Reactive NMVOCs decline in Birmingham, but the trend is not significant. There is a recent (2012–2018) steep (> 9 % a−1) increase in reactive NMVOCs in London. The cause for this rapid increase is uncertain but may reflect the increased contribution of oxygenated volatile organic compounds (VOCs) from household products, the food and beverage industry, and domestic wood burning, with implications for the formation of ozone in a VOC-limited city.

Download Full-text

Development of a Water Matrix Certified Reference Material for Volatile Organic Compounds Analysis in Water

Molecules ◽

10.3390/molecules26144370 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4370

Author(s):

Liping Fang ◽

Linyan Huang ◽

Gang Yang ◽

Yang Jiang ◽

Haiping Liu ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Reference Material ◽

Organic Compounds ◽

Certified Reference Material ◽

Pure Water ◽

Term Stability ◽

Long Term Stability ◽

Water Matrix ◽

Volatile Organic

Water matrix certified reference material (MCRM) of volatile organic compounds (VOCs) is used to provide quality assurance and quality control (QA/QC) during the analysis of VOCs in water. In this research, a water MCRM of 28 VOCs was developed using a “reconstitution” approach by adding VOCs spiking, methanol solution into pure water immediately prior to analysis. The VOCs spiking solution was prepared gravimetrically by dividing 28 VOCs into seven groups, then based on ISO Guide 35, using gas chromatography-mass spectrometry (GC-MS) to investigate the homogeneity and long-term stability. The studies of homogeneity and long-term stability indicated that the batch of VOCs spiking solution was homogeneous and stable at room temperature for at least 15 months. Moreover, the water MCRM of 28 VOCs was certified by a network of nine competent laboratories, and the certified values and expanded uncertainties of 28 VOCs ranged from 6.2 to 17 μg/L and 0.5 to 5.3 μg/L, respectively.

Download Full-text

Root anoxia effects on physiology and emissions of volatile organic compounds (VOC) under short- and long-term inundation of trees from Amazonian floodplains

SpringerPlus ◽

10.1186/2193-1801-1-9 ◽

2012 ◽

Vol 1 (1) ◽

pp. 9 ◽

Cited By ~ 17

Author(s):

Araceli Bracho-Nunez ◽

Nina Knothe ◽

Wallace R Costa ◽

Liberato R Maria Astrid ◽

Betina Kleiss ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Volatile Organic ◽

Short And Long Term

Download Full-text

Long-term soil biological fertility, volatile organic compounds and chemical properties in a vineyard soil after biochar amendment

Geoderma ◽

10.1016/j.geoderma.2019.03.011 ◽

2019 ◽

Vol 344 ◽

pp. 127-136 ◽

Cited By ~ 11

Author(s):

Laura Giagnoni ◽

Anita Maienza ◽

Silvia Baronti ◽

Francesco Primo Vaccari ◽

Lorenzo Genesio ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Chemical Properties ◽

Volatile Organic ◽

Vineyard Soil ◽

Biochar Amendment ◽

And Chemical Properties

Download Full-text

Long-term Emission of Volatile Organic Compounds from Waterborne Paints - Methods of Comparison

Indoor Air ◽

10.1111/j.1600-0668.1991.00019.x ◽

1991 ◽

Vol 1 (4) ◽

pp. 562-576 ◽

Cited By ~ 45

Author(s):

Per A. Clausen ◽

Peder Wolkoff ◽

Erik Hoist ◽

Peter A. Nielsen

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Volatile Organic

Download Full-text

Physicochemical uptake and release of volatile organic compounds by soil in coated-wall flow tube experiments with ambient air

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-2209-2019 ◽

2019 ◽

Vol 19 (4) ◽

pp. 2209-2232 ◽

Cited By ~ 3

Author(s):

Guo Li ◽

Yafang Cheng ◽

Uwe Kuhn ◽

Rongjuan Xu ◽

Yudong Yang ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Atmospheric Chemistry ◽

Soil Surface ◽

Ambient Air ◽

Flow Tube ◽

Heterogeneous Oxidation ◽

Volatile Organic ◽

Wall Flow

Abstract. Volatile organic compounds (VOCs) play a key role in atmospheric chemistry. Emission and deposition on soil have been suggested as important sources and sinks of atmospheric trace gases. The exchange characteristics and heterogeneous chemistry of VOCs on soil, however, are not well understood. We used a newly designed differential coated-wall flow tube system to investigate the long-term variability of bidirectional air–soil exchange of 13 VOCs under ambient air conditions of an urban background site in Beijing. Sterilized soil was investigated to address physicochemical processes and heterogeneous/multiphase reactions independently from biological activity. Most VOCs revealed net deposition with average uptake coefficients (γ) in the range of 10−7–10−6 (referring to the geometric soil surface area), corresponding to deposition velocities (Vd) of 0.0013–0.01 cm s−1 and soil surface resistances (Rc) of 98–745 s cm−1, respectively. Formic acid, however, was emitted at a long-term average rate of ∼6×10-3 nmol m−2 s−1, suggesting that it was formed and released upon heterogeneous oxidation of other VOCs. The soil–atmosphere exchange of one individual VOC species can be affected by both its surface degradation/depletion caused by surface reactions and by competitive uptake or heterogeneous formation/accommodation of other VOC species. Overall, the results show that physicochemical processing and heterogeneous oxidation on soil and soil-derived dust can act as a sink or as a source of atmospheric VOCs, depending on molecular properties and environmental conditions.

Download Full-text