2015 Volume 28 Issue 5 Pages 555-562
For introducing the use of fine bubbles (FB) in industrial applications, it is important to understand their properties and the mechanisms of the effect in order to utilize them effectively. However, it is difficult to observe FB directly because of their small size. We measured the electrochemical properties of water containing FB in order to examine the effect of FB on ions macroscopically. The conductivity of the FB water generated from purified water was lower than that of the purified water. In particular, the decrease in the conductivity of the FB water supports the hypothesis that ions are closely involved in the generation mechanism of FB. We also analyzed the effect of FB water on the nutrient uptake of soybean seedlings. For the uptake experiment, we used radio isotope elements (137Cs, 22Na, 32P) at different pH conditions. As a result, we have found the increased uptake of 137Cs and 22Na and the decreased uptake of 32P compared with distilled water. There was no correlation between pH value and the effect of FB water. Transpiration rate was not significantly different between FB water and distilled water. Although questions still remain in the elements efficiency in ions (anion or cation), these results suggest a possible influence of fine bubbles on the plant activity to uptake nutrient ions.