Three kinds of flowing-cycle reoxygenation devices for emergency reoxygenation to deal with outbreak of "black water group" of shallow lake were developed. The principle of the devices was aeroelastic enhancing circulation flow. The three devices were type Ⅰ of closed aeration

type Ⅱ of exposure aeration

type Ⅲ of exposure packing aeration. Klas indicators of small test showed that type Ⅲ was higher than typeⅠ and type Ⅱ by 179% and 51% respectively; Qc of type Ⅲ was higher than type Ⅰ and type Ⅱ by 167% and 50% respectively; e of type Ⅲ was higher than type I and type Ⅱ by 176% and 51% respectively; E of type Ⅲ was higher than type I and type Ⅱ by 29% and 50% respectively. In pilot scale test dead algae water was mixed with lake water to simulate the "black water group" in a blue algae settling pond of Taihu lake whose depth was 1.8 m and area was 200 m2

and in this test the pilot type Ⅲ multi-faceted spherical packing device could restore dissolved oxygen from 0 mg·L-1 to 1.69 mg·L-1 in 28 h

the device oxygen efficiency was 26%

and the degradation of water CODCr

ammonia nitrogen was satisfactory. The device could be used for emergency management of black water group outbreak such as in Taihu lake.