The harmful effect of direct air sparging on Phaeodactylum tricornutum microalgal cultures
was investigated in bubble columns and airlift photobioreactors with various superficial air
velocities and two types of spargers which generated different sizes of bubbles. Small
bubbles bursting at the surface of the culture were apparently the main cause of cell damage
in batch cultures in laboratory-scale bubble columns. Other mechanisms of cell damage also
were a contributing factor to the observed cell loss in outdoor pilot-scale bubble columns …