depletion rendered by decaying algae will further induce heterotrophic conditions in the riverine sections
and cause a dysfunction of the whole aquatic ecosystem[14-15].
There are a large number of studies on the blue-green algal bloom in the world. The Microcystis is one
of the typical dominant species. Dissolved oxygen is used to indicate the water quality when the
Microcystis bloom occurs. Oxygen can increase due to phytoplankton photosynthesis and reaeration, and
decrease owing to phytoplankton respiration, organic matter oxidization, nitrification and sediment
decomposition, which should be considered in the research of Microcystis algal bloom [16]. In this paper,
Microcystis blooms are simulated in the experiments through controlling the initial phosphor and nitrogen
concentrations, and the complex of environmental and nutrient conditions, respectively. The variations of
dissolved oxygen in the series experiments are analyzed in order to find the main process which affects
the variation of dissolved oxygen. In addition, the dynamic model for dissolved oxygen are built and
parameterized from the results of experiments. The results can provide help for researches of algal bloom