Bubble aspect ratios and rising velocities of dodecylamine (DDA), methyl isobutyl carbinol (MIBC), sec-octyl alcohol (2-octanol), DDA-MIBC blend, and DDA-2-octanol blend were investigated for different concentrations. The bubble aspect ratio of these individual reagents was found to follow the same order as molecular weight: DDA>2-octanol>MIBC. DDA addition further increased the aspect ratio of the bubbles in the individual MIBC and 2-octanol solutions, and the aspect ratio of the DDA-MIBC blend was found to be smaller than that of the DDA-2-octanol blend for a random but identical reagent concentration. The bubble rising velocity of these individual reagents followed the order MIBC>2-octanol>DDA. DDA addition had a significant effect in terms of decreasing the rising velocity of the bubbles in the individual MIBC and 2-octanol solutions; meanwhile, the bubble rising velocity of the DDA-MIBC blend was larger than that of the DDA-2-octanol blend. Bubble rising velocity showed a negative linear correlation with aspect ratio that was independent of reagent type, concentration, and blend. (C) 2018 Published by Elsevier B.V.