Microbubbles oxygen transfer to water was simulated based on experimental results obtained from the bubbles generation operated under varying liquid supply velocity to the multi-step orifices of the generator. It had been known that liquid supply velocity and bubble size are inversely related. In the oxygen transfer, a non-steady state was assumed and the pseudo stagnation caused the slow movement of bubbles from the bottom to the water surface. Two parameters were considered for the simulation: They represent a factor to correct the pseudo stagnation state and a scale which represented the amount of bubbles in supply versus time. The sum of absolute error determined by fitting regression to the experimental results was comparable to that of the American Society of Civil Engineers (ASCE) model, which is based on concentration differential as the driving force. Hence, considering the bubbles formation factors, the simulation process has the potential to be easily used for applications by introducing two parameters in the assumptions. Compared with the ASCE model, the simulation method reproduced the experimental results well by detailed conditions.

ABSTRACT
 1. Introduction
 2. Methodology
  2.1 Simulation
  2.2 Experiment
 3. Result and Discussion
  3.1 DO transient model
  3.2 Shrinkage of bubble
 4. Conclusions
 References

• Jaiyeop Lee(Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT)) | 이재협
• Ilho Kim(Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT), Department of Construction Environment Engineering, University of Science and Technology) | 김일호 Corresponding author