Dependence of Oxygen Transfer Rate on Energy Dissipation during Surface Aeration and in Stream Flow

Abstract

The transfer rate of oxygen from the aqueous phase to the atmosphere is approximately proportional to the power dissipation per unit volume. Such proportionality has been observed in mechanical surface aeration as well as natural waters. For oxygen transfer, the coefficient of proportionality is estimated as approximately 2.5 × 10⁻⁵ (m³ •W⁻¹ •s⁻¹) based on mechanical aeration experiments in the laboratory, compared to 3.6 × 10⁻⁵ to 7.2 × 10⁻⁵ (m•W ⁻¹•s⁻¹) for standard clean water testa of large-scale surface aerators, and to approximately 1.8 × 10⁻⁵ (m³•W⁻¹ •s⁻¹) for observations of natural stream reaeration. Surface renewal theory predicts a weaker dependence of mass transfer on power dissipation.