CFD modeling of different mass transfer coefficients on hydrogen sulfide emission in a flux chamber

Hydrogen sulfide (H₂S) is commonly used as an indicator for odorous gas emission monitoring in wastewater treatment plants. The H₂S emission estimations can be performed using algebraic mathematical models or carrying out measurements at the source, with the dynamic flux chamber, for example. This work brings together these two methodologies in a computational fluid dynamics analysis. Fifteen liquid-phase mass transfer coefficient ([Formula: see text]) models were initially evaluated in establishing, at the liquid-gas interface in a flux chamber, an H₂S emission flux based on the friction velocity field from three different inlet flows (2, 5, and 10 L min^-1). Ten [Formula: see text] models were fully simulated, and the numerical results were compared with available experimental data. The higher the inlet flow, the higher the friction velocity at the interface, and the higher the H₂S emission. The H₂S emission was also strongly dependent on the constant coefficients of the existing [Formula: see text] models. Small variability on those coefficients generates considerable changes in emissions at the interface. Few and different models performed well in describing the available concentration data at the outlet sampling probe for different inlet flows, which shows there is still no single model capable of representing all simulated friction velocity ranges (0.005 to 0.017 m s^-1).