OXYGEN ABSORPTION IN BUBBLE AERATION (III)

Abstract

Using a strain of Pseudomonas ovalis investigations were made on the oxygen absorption in bubble aeration in the process of gluconic acid fermentation. The oxygen transfer coefficients (k_L and k_m) of liquid films which were assumed to exist around air bubbles and resting cells were estimated. It was difficult to recognize a substantial difference between the values of k_L and k_m; the film coefficient k_m of the cells was found to be in the range from about 10^-1 to 10^-3cm/sec, while the value of k_L was of the order of 10^-2cm/sec corresponding to the bubble diameter of several millimeters.
It was also found that the value of k_m was large compared with the corresponding value (k′_m) obtained for the cells without aeration. The ratio k′_m/k_m extended from 0.53 to 0.85, showing no appreciable change according to the rate of aeration ranging from 0.5 to 5.0vvm.