Hydrogen sulfide gas emission under turbulent conditions - an experimental approach for free-fall drops.
Odor nuisance and sulfide corrosion in sewers carrying septic wastewater are accelerated at points of turbulence such as drops in manholes, but accurate methods or empirical expressions to evaluate the gas stripping rate at those particular sites are still missing. With the aim of improving the current knowledge on the influence of free-fall drops on the release of hydrogen sulfide gas, an experimental set-up was built allowing different free-fall drops heights and flows. Three types of experiments were carried out: reaeration tests without sulfide; sulfide oxidation tests; and hydrogen sulfide release tests. With the increase of the free-fall drop height or of the flow, a higher rate of air-to-water mass oxygen transfer was observed. Results regarding sulfide oxidation tests with reaeration through the free-fall have shown that the oxidation rate was correlated with flow. In the hydrogen sulfide release tests, the maximum concentration in the atmosphere reached 500 ppm. Results also showed that increasing the flow rate decreased the time at which the maximum concentrations in the atmosphere were observed.
Department of Civil Engineering, Architecture and Georesources (DECivil) & Centre for Hydrosystems Research (CEHIDRO), Technical University of Lisbon, Instituto Superior Técnico (IST), Avenida Rovisco Pais, 1049-001 Lisbon, Portugal E-mail: natercia.matias@ist.utl.pt.
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Matias
Department of Civil Engineering, Architecture and Georesources (DECivil) & Centre for Hydrosystems Research (CEHIDRO), Technical University of Lisbon, Instituto Superior Técnico (IST), Avenida Rovisco Pais, 1049-001 Lisbon, Portugal E-mail: natercia.matias@ist.utl.pt.
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JS
Matos
Department of Civil Engineering, Architecture and Georesources (DECivil) & Centre for Hydrosystems Research (CEHIDRO), Technical University of Lisbon, Instituto Superior Técnico (IST), Avenida Rovisco Pais, 1049-001 Lisbon, Portugal E-mail: natercia.matias@ist.utl.pt.
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Ferreira
D006862:Hydrogen Sulfide / Q000737:chemistry*; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid / Q000379:methods*
D006862:Hydrogen Sulfide