3.2.2 Size distribution of microbubble and Microcystis
When the microbubbles adhere to Microcystis , the size
distribution of microbubble-algae aggregates is shown in Fig.5. The
particle size of microbubbles in the microbubble-algae complex was in
the range of 10~170 μm, and the size ofMicrocystis was in the range of 10~400 μm. Among
them, the proportion of microbubbles with a particle size of
70~125 μm is as high as 87%, and 85% ofMicrocystis are concentrated in 50~200 μm. In the
size-frequency distribution curve of adhered Microcystis (Fig.
5(b)A), the peak frequency of Microcystis appeared at 100 μm
(8.5%), that is, Microcystis in the range of
90~100 μm accounted for 8.5% of the totalMicrocystis . In the particle size distribution curve of
microbubbles (total microbubbles) adhering to Microcystis (Fig.
5(b)B), the peak frequency of microbubble size appeared at 90 μm
(12.0%), that is, microbubbles with particle size between
80~90 μm accounted for 12.0% of the total microbubbles.
In the particle size distribution of microbubbles generated under this
working condition (see Fig. 5(b)C), 45.8% of the microbubbles were
distributed between 40 and 60 μm, and the proportion of microbubbles
adhering to Microcystis (80~90 μm) was less than
1%. The frequency distribution peak of the particle size of the adhered
microbubbles is like that of the microalgae. It was reported that
morphology of algae including shape and size also have impacts on the
performance of flotation process when considering the bubble-cell
attachment, in addition, spherical (Microcystis ) and oval
(Chlamydomonas ) configures had greater flotation efficiencies
than filamentous shape (Phormidium ) (Bui et al., 2015).