“…However, bubble transfer is the predominant means of oxygen transfer. So far, considerable research interests have been focused on the enhancement of the bubble transfer efficiency by developing a wide variety of new aeration techniques, including the utilization of high-purity-oxygen aeration system [4][5][6][7][8][9][10], deep aeration system [11][12][13] and fine bubble diffuser [14][15][16][17], etc. Nevertheless, only a little effort has been devoted to the research on the improvement of surface transfer efficiency.…”