Abstract
By changing the size of air bubbles from about 8.8mm to 1.6mm, the effect of a surfactant on the value of liquid film coefficient of oxygen transfer was studied experimentally. With bubbles larger than 2mm up to the experimental limit of 8.8mm in size, no appreciable differences were observed related to the size of bubbles irrespective of the cases with and without the surfactant.
An assumption that the increase of resistance to oxygen transfer in bubble aeration, in which the surfactant is involved was primarily due to the specific action of surfactant in calming the complicated motion of bubbles at the interface, was discussed with reference to the theoretical analyses which have already been made available from either the penetration theory or the boundary layer theory of mass transfer.
If the size of the bubbles was reduced less than about 2mm in size, the increase of resistance to oxygen transfer in bubble aeration was appreciable enough in both cases with and without the surfactant.
