Abstract
Suppression of dinoflagellate Peridinium bipes bloom by ultraviolet (UV) radiation was surveyed in a mesocosm. The mesocosm was 5m long, 5m wide, 4m deep, and contained a UV lamp 123cm long with a output power of 30W emitting 253.7nm light. The mesocosm was placed in a reservoir. Almost all live cells were eliminated from the water within 2days. Transparency increased from 2.9m to higher than 4.5m in 4 days. Although ammonium nitrogen increased, no notable changes were observed in the concentrations of the important nutrients for algal growth such as orthophosphate and nitrate nitrogen. Therefore UV radiation was taken to be an effective way of suppression of P. bipes bloom. According to the results obtained from the mesocosm experiment, the number of UV lamps and the days required for killing all the cells in a reservoir were estimated.
