title: Dynamic flux chamber measurements of hydrogen sulfide emission rate from a quiescent surface--A computational evaluation.
abstract: Enclosure devices have been studied and used for research purposes and practical applications in order to measure the emission rate of odorous pollutants from quiescent liquid surfaces to atmosphere. However, important questions remain about the interference of these measuring devices on the actual emission rate. The main concern regarding the use of a flux chamber is the fact that odorous compounds can accumulate into the chamber and yield gas-phase concentration increase inside the equipment, which causes a reduction of the emission rate during the measurement and thus gives an inaccurate local emission rate. Furthermore, the fluid flow inside the chamber does not reproduce the atmospheric boundary layer flow. This study applied the Computational Fluid Dynamics (CFD) technique in order to investigate the influence of the fluid flow features inside a flux chamber on the measured hydrogen sulfide emission rate at quiescent liquid surfaces. The flux chamber design and operational conditions are those supported by the United States Environmental Protection Agency (US EPA). The results show that the US EPA flux chamber presents a fairly well mixed air phase. However, a trend to stagnation and hydrogen sulfide accumulation near chamber walls was detected in the computational simulation, which also indicated that the positioning of the sampling tube in relation to the inlet orifices may lead to deviations in the measurement results. CFD results showed that the wall shear and concentration gradients spatially vary at the gas-liquid interface, and friction velocity inside the chamber does not match typical values of atmospheric flow.
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil; UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Ademir A
authors.initials: AA
authors.lastname: Prata
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Jane M
authors.initials: JM
authors.lastname: Santos
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Sandra P
authors.initials: SP
authors.lastname: Beghi
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Isabella F
authors.initials: IF
authors.lastname: Fernandes
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Lya L C
authors.initials: LL
authors.lastname: Vom Marttens
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Leovegildo I
authors.initials: LI
authors.lastname: Pereira Neto
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Ramon S
authors.initials: RS
authors.lastname: Martins
authors.affiliation: Departamento de Engenharia Ambiental, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, 29.060-970, Vitória, ES, Brazil.
authors.forename: Neyval C
authors.initials: NC
authors.lastname: Reis
authors.affiliation: UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia. Electronic address: r.stuetz@unsw.edu.au.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Stuetz
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D003198:Computer Simulation; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D006862:Hydrogen Sulfide / Q000032:analysis*; D009812:Odorants / Q000032:analysis*; D013499:Surface Properties; D014481:United States; D062065:Wastewater / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D006862:Hydrogen Sulfide; D062065:Wastewater
keywords: Area sources; Computational fluid dynamics; Dynamic flux chamber; Odour emission