Seasonal variations in VOC emission rates from gorse (Ulex europaeus)

Abstract. Seasonal variations of Q. pubescens physiology and isoprene emission rates (ER) were studied from June 2012 to June 2013 at the O3HP site (French Mediterranean) under natural (ND) and amplified (+30 %, AD) drought. While AD significantly reduced the stomatal conductance to water vapour over the season excepting August, it did not significantly limit CO2 net assimilation, which was the lowest in summer. ER followed a significant seasonal pattern, whatever the drought intensity, with mean ER maxima of 78.5 and 104.8 µgC gDM−1 h−1 in July (ND) and August (AD) respectively. Isoprene emission factor increased significantly by a factor of 2 in August and September under AD (137.8 and 74.3 µgC gDM−1 h−1) compared to ND (75.3 and 40.21 µgC gDM−1 h−1), but no changes occurred on ER. An isoprene algorithm (G14) was developed using an optimised artificial neural network trained on our experimental dataset (ER + O3HP climatic and edaphic parameters cumulated over 0 to 21 days before measurements). G14 assessed more than 80 % of the observed ER seasonal variations, whatever the drought intensity. In contrast, ER was poorly assessed under water stress by MEGAN empirical isoprene model, in particular under AD. Soil water (SW) content was the dominant parameter to account for the observed ER variations, regardless the water stress treatment. ER was more sensitive to higher frequency environmental changes under AD (0 to −7 days) compared to ND (7 days). Using IPCC RCP2.6 and RCP8.5 climate scenarios, SW and temperature calculated by the ORCHIDEE land surface model, and G14, an annual 3 fold ER relative increase was found between present (2000–2010) and future (2090–2100) for RCP8.5 scenario compared to a 70 % increase for RCP2.6. Future ER remained mainly sensitive to SW (both scenarios) and became dependent to higher frequency environmental changes under RCP8.5.

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Chemical composition analysis and its application in estimation of VOC emission rates from hydrocarbon solvent-based indoor materials

Chemosphere ◽

10.1016/s0045-6535(99)00156-3 ◽

1999 ◽

Vol 39 (14) ◽

pp. 2535-2547 ◽

Cited By ~ 6

Author(s):

Jiping Zhu ◽

Jianshun Zhang ◽

Chia-Yu Shaw

Keyword(s):

Chemical Composition ◽

Composition Analysis ◽

Emission Rates ◽

Voc Emission ◽

Hydrocarbon Solvent ◽

Chemical Composition Analysis ◽

Indoor Materials

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Seasonal variations of O<sub>2</sub> atmospheric and OH(6−2) airglowand temperature at mid-latitudes from SATI observations

Annales Geophysicae ◽

10.5194/angeo-22-819-2004 ◽

2004 ◽

Vol 22 (3) ◽

pp. 819-828 ◽

Cited By ~ 31

Author(s):

M. J. López-González ◽

E. Rodríguez ◽

R. H. Wiens ◽

G. G. Shepherd ◽

S. Sargoytchev ◽

...

Keyword(s):

Seasonal Variation ◽

Key Words ◽

Sierra Nevada ◽

Seasonal Variations ◽

Annual Variation ◽

Emission Rate ◽

Atmospheric Composition ◽

Emission Rates ◽

Composition And Structure ◽

Instruments And Techniques

Abstract. More than 3 years of airglow observations with a Spectral Airglow Temperature Imager (SATI) installed at the Sierra Nevada Observatory (37.06°N, 3.38°W) at 2900m height have been analyzed. Values of the column emission rate and vertically averaged temperature of the O2 atmospheric (0–1) band and of the OH Meinel (6–2) band from 1998 to 2002 have been presented. From these observations a clear seasonal variation of both emission rates and rotational temperatures is inferred at this latitude. It is found that the annual variation of the temperatures is larger than the semi-annual variation, while for the emission rates the amplitudes are comparable. Key words. Atmospheric composition and structure (airglow and aurora; pressure density and temperature; instruments and techniques)

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Exposure level and emission characteristics of ammonia and hydrogen sulphide in poultry buildings of South Korea

Indoor and Built Environment ◽

10.1177/1420326x16664776 ◽

2016 ◽

Vol 26 (8) ◽

pp. 1168-1176

Author(s):

Ki Y. Kim

Keyword(s):

South Korea ◽

Hydrogen Sulphide ◽

Seasonal Variations ◽

Emission Rate ◽

Field Investigation ◽

Exposure Level ◽

Emission Characteristics ◽

Emission Rates ◽

Building Area ◽

Broiler House

The purpose of this study is to estimate the concentrations and emission rates of ammonia and hydrogen sulphide released from poultry buildings situated in South Korea by field investigation. Mean concentrations of ammonia and hydrogen sulphide emitted from poultry buildings were 18.8 (±4.90) ppm and 945 (±519) ppb for caged layer house, 15.2 (±3.21) ppm and 603 (±274) ppb for broiler house, and 6.45 (±1.85) ppm and 247 (±184) ppb for layer house with manure belt, respectively. Seasonal variations in concentrations of ammonia and hydrogen sulphide in poultry building were observed highest in winter, lowest in summer (p < 0.01). Based on animal unit (AU), mean emission rates of ammonia and hydrogen sulphide were 4493 (±2095) mg AU−1 h−1 and 4493 (±2095) mg AU−1 h−1, respectively. Those of ammonia and hydrogen sulphide in terms of poultry building area were 278 (±130) mg m−2 h−1 and 12.3 (±9.20) mg m−2 h−1, respectively. Exposure level and emission rate of ammonia and hydrogen sulphide were highest in caged layer house, followed by broiler house and layer house with manure belt (p < 0.05). This finding implicates that the caged layer house among types of poultry building in South Korea should be managed optimally to lessen generation of ammonia and hydrogen sulphide.

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A rapid technique for monitoring volatile organic compound emissions from wood–plastic composites

Indoor and Built Environment ◽

10.1177/1420326x16669976 ◽

2016 ◽

Vol 27 (2) ◽

pp. 194-204 ◽

Cited By ~ 2

Author(s):

Taneli Väisänen ◽

Kimmo Laitinen ◽

Laura Tomppo ◽

Jorma Joutsensaari ◽

Olavi Raatikainen ◽

...

Keyword(s):

Indoor Air ◽

Proton Transfer Reaction ◽

Emission Rates ◽

Wood Plastic Composites ◽

Voc Emission ◽

Plastic Composites ◽

Volatile Organic ◽

Volatile Organic Compound Emissions ◽

The Impact ◽

Tof Ms

Wood–plastic composites (WPCs) have numerous indoor applications, including framing, decoration and flooring. However, the impact of WPCs on indoor air quality has not been widely studied. Proton-transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) was utilized to monitor the release of volatile organic compounds (VOCs) from a commercial WPC for 41 days since its day of manufacture. Additionally, the emission rates of VOCs from seven different WPC samples were compared and converted into air concentrations to evaluate whether the odour thresholds would be exceeded. The VOCs studied were formaldehyde, acetaldehyde, acetic acid, cyclohexene, furan, furfural, guaiacol and monoterpenes. The results from the 41-day test revealed that the emission rates of monoterpenes, guaiacol, furfural and acetaldehyde declined by 75%–93%, whereas an opposite phenomenon was observed for cyclohexene (nearly a threefold increase). The comparison of VOC emission rates from seven WPC samples indicated that none of the samples had the lowest or highest emission rate for every VOC studied. The present results are significant in at least two aspects; this study shows that the VOC emission rates from WPCs can be determined by using PTR-TOF-MS. Furthermore, it seems that guaiacol and acetaldehyde exceed their odour thresholds and therefore humans will be able to detect these compounds from the WPCs studied.

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Estimation of VOC emission rates from FTIR measurements and whole-air canister data

10.1117/12.210797 ◽

1995 ◽

Cited By ~ 3

Author(s):

Ray E. Carter, Jr. ◽

Dennis D. Lane ◽

Glen A. Marotz ◽

Michael F. Davis ◽

Jody L. Hudson ◽

...

Keyword(s):

Emission Rates ◽

Voc Emission

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