title: Influence of relative air/water flow velocity on oxygen mass transfer in gravity sewers.
abstract: Problems related to hydrogen sulfide may be serious for both network stakeholders and the public in terms of health, sustainability of the sewer structure and urban comfort. H2S emission models are generally theoretical and simplified in terms of environmental conditions. Although air transport characteristics in sewers must play a role in the fate of hydrogen sulfide, only a limited number of studies have investigated this issue. The aim of this study was to better understand H2S liquid to gas transfer by highlighting the link between the mass transfer coefficient and the turbulence in the air flow and the water flow. For experimental safety reasons, O2was taken as a model compound. The oxygen mass transfer coefficients were obtained using a mass balance in plug flow. The mass transfer coefficient was not impacted by the range of the interface air-flow velocity values tested (0.55-2.28 m·s-1) or the water velocity values (0.06-0.55 m·s-1). Using the ratio between kL,O2to kL,H2S, the H2S mass transfer behavior in a gravity pipe in the same hydraulic conditions can be predicted.
authors.affiliation: Laboratory of Civil and Environmental Engineering, University of Lyon, INSA-Lyon, DEEP - EA 7429, 9 rue de la Physique, F69621 Villeurbanne France E-mail: pierre.buffiere@insa-lyon.fr.
authors.forename: Lucie
authors.initials: L
authors.lastname: Carrera
authors.affiliation: Laboratory of Civil and Environmental Engineering, University of Lyon, INSA-Lyon, DEEP - EA 7429, 9 rue de la Physique, F69621 Villeurbanne France E-mail: pierre.buffiere@insa-lyon.fr.
authors.forename: Fanny
authors.initials: F
authors.lastname: Springer
authors.affiliation: Laboratory of Civil and Environmental Engineering, University of Lyon, INSA-Lyon, DEEP - EA 7429, 9 rue de la Physique, F69621 Villeurbanne France E-mail: pierre.buffiere@insa-lyon.fr.
authors.forename: Gislain
authors.initials: G
authors.lastname: Lipeme-Kouyi
authors.affiliation: Laboratory of Civil and Environmental Engineering, University of Lyon, INSA-Lyon, DEEP - EA 7429, 9 rue de la Physique, F69621 Villeurbanne France E-mail: pierre.buffiere@insa-lyon.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Buffiere
mesh_terms: D000388:Air / Q000032:analysis*; D006112:Gravitation; D006862:Hydrogen Sulfide / Q000737:chemistry; D008962:Models, Theoretical; D010100:Oxygen / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry*
chemical_list: D012722:Sewage; D014867:Water; D010100:Oxygen; D006862:Hydrogen Sulfide