Abstract：To study the effect of surfactants on oxygenation capacity, oxygen mass transfer efficiency was investigated in a three-phase aeration reactor where four kinds of granular bio-media as well as surfactants were tested. It was found that the oxygenation efficiency decreased obviously by SDBS and the KLa(20) reached a minimum when the concentration was around 7×10-5mol/L. However, the mass transfer coefficient was enhanced in the presence of CTAB where its concentration was in the range of 3.5×10-5~8.1×10-4mol/L.According to the comparative investigation of effects on oxygenation efficiency among different granular bio-media,it can be regarded that the mass transfer coefficient KLa(20) was enhanced in the presence of bio-medias.The KLa(20) was approximately doubled in the presence of sponge.The results also suggest that double electrical layer mechanism of ionic surfactant molecules and surface tension variations may had influenced the mass transfer efficiency and addition of bio-media should be a method for the mass transfer improvement.
