Volatile organic compounds in urban atmospheres: Long-term measurements of ambient air concentrations in differently loaded regions of Leipzig

1997 ◽  
Vol 359 (2) ◽  
pp. 189-197 ◽  
Author(s):  
T. Knobloch ◽  
A. Asperger ◽  
W. Engewald
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Ambient Air ◽  
Volatile Organic ◽  
Air Concentrations ◽  
Urban Atmospheres

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

2019 ◽  
Vol 19 (4) ◽  
pp. 2209-2232 ◽  
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.

Using long-term air monitoring of semi-volatile organic compounds to evaluate the uncertainty in polyurethane-disk passive sampler-derived air concentrations

2017 ◽  
Vol 220 ◽  
pp. 1100-1111 ◽  
Author(s):  
Eva Holt ◽  
Pernilla Bohlin-Nizzetto ◽  
Jana Borůvková ◽  
Tom Harner ◽  
Jiří Kalina ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Passive Sampler ◽  
Air Monitoring ◽  
Volatile Organic ◽  
Air Concentrations

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

2018 ◽  
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 at 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.

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