| Title: | Impact of trees on gas concentrations and condensables in a 2-D street canyon using CFD coupled to chemistry modeling |
| Author(s): | Wang Y; Flageul C; Maison A; Carissimo B; Sartelet K; |
| Address: | "CEREA, Ecole des Ponts ParisTech, EDF R&D, 6-8 Avenue Blaise Pascal, 77455, Marne la Vallee, France. Electronic address: yunyi.wang@enpc.fr. PPRIME institute, Curiosity Group, Universite de Poitiers, CNRS, ISAE-ENSMA, Poitiers, France. CEREA, Ecole des Ponts ParisTech, EDF R&D, 6-8 Avenue Blaise Pascal, 77455, Marne la Vallee, France; Universite Paris-Saclay, INRAE, AgroParisTech, UMR EcoSys, 78850, Thiverval-Grignon, France. CEREA, Ecole des Ponts ParisTech, EDF R&D, 6-8 Avenue Blaise Pascal, 77455, Marne la Vallee, France" |
| DOI: | 10.1016/j.envpol.2023.121210 |
| ISSN/ISBN: | 1873-6424 (Electronic) 0269-7491 (Linking) |
| Abstract: | "Trees grown in streets impact air quality by influencing ventilation (aerodynamic effects), pollutant deposition (dry deposition on vegetation surfaces), and atmospheric chemistry (emissions of biogenic volatile organic compounds, BVOCs). To qualitatively evaluate the impact of trees on pollutant concentrations and assist decision-making for the greening of cities, 2-D simulations on a street in greater Paris were performed using a computational fluid dynamics tool coupled to a gaseous chemistry module. Globally, the presence of trees has a negative effect on the traffic-emitted pollutant concentrations, such as NO(2) and organic condensables, particularly on the leeward side of a street. When not under low wind conditions, the impact of BVOC emissions on the formation of most condensables within the street was low owing to the short characteristic time of dispersion compared with the atmospheric chemistry. However, autoxidation of BVOC quickly forms some extremely-low volatile organic compounds, potentially leading to the formation of ultra-fine particles. Planting trees in streets with traffic is only effective in mitigating the concentration of some oxidants such as ozone (O(3)), which has low levels in cities regardless of this, and hydroxyl radical (OH), which may slightly lower the rate of oxidation reactions and the formation of secondary species in the street" |
| Keywords: | "*Air Pollutants/analysis Trees *Volatile Organic Compounds/analysis *Air Pollution/analysis Wind Cities *Environmental Pollutants Vehicle Emissions/analysis Models, Theoretical Cfd Secondary aerosols Street canyon;" |
| Notes: | "MedlineWang, Yunyi Flageul, Cedric Maison, Alice Carissimo, Bertrand Sartelet, Karine eng England 2023/02/12 Environ Pollut. 2023 Apr 15; 323:121210. doi: 10.1016/j.envpol.2023.121210. Epub 2023 Feb 9" |
