Figure 1 Flow chart of test equipment (1) Reservoir (2) Gasometer (3) Gas-liquid mixing pump (4) Dissloved air vessel (5) Air flotation column (6) Pressure gage (7) Valve (8) Relief valve (9) Flowmeter (10) Safety valve (11) Union (12) The release pipe (13) Light source (14) Microalgae (15) injector (16) bubble (17) high-speed camera)