Abstract
Recently, micro-bubbles are generated by some methods and used at various situations. However, physical characteristics for micro-bubbles are not understood very well. In this study, micro-bubbles generated by the pressurizing dissolution method are compared with those generated by the shear method, and the relation between some bubble size populations and their effects of oxygen supplying are discussed. We found that the bubbles generated by the pressurizing dissolution method, which are very small, have advantageous to the effect of oxygen supplying at the same air flow rate, but it is not so effective considering the flow rate through the interfacial area of bubbles. We also presented the relation between four parameters and the overall volumetric mass transfer coefficient.
