Abstract:In order to explore the impacts of flow velocity on growth of dominant species of algae-bloom in reservoirs

a laboratory experiment was conducted to examine the responses of the algae growth

water quality

lipid oxidation and antioxidant system of Microcystis aeruginosa under different flow velocities (0-0.3 m/s). Significant differences were found in the growth of M. aeruginosa under different flow velocities

namely the low flow velocity promoting the algae growth and the high flow velocity inhibiting growth. The algae under 0.1 m/s grew best with the fastest consumption of total nitrogen and total phosphorus

while the algae under 0.3 m/s grew significantly worse than static group. Along with the growth of algae

the water pH tended to be weakly alkaline

the dissolved oxygen content in water increased slowly and water turbidity kept high correlation with algae density. MDA content and antioxidant enzymes (SOD

CAT

POD) activity of the algae under 0.3 m/s was significantly higher than the other groups. The results showed that a certain rage of flow velocity could improve the floating and aggregation of algae

promote absorbing light energy

enhance the nutrient absorption of the algae and reduce the oxidation degree of algae cells. The empirical formulas of algae growth prediction under hydrodynamic conditions during experiment period were established

and the advantaged flow velocity for the algae growth was determined to be 0.15 m/s. The outcome might provide a theoretical basis for the prediction of eutrophication trend of reservoir and useful reference for the prevention and control of M. aeruginosa bloom.