Water treatment device

The utility model relates to a water treatment device. The device comprises a rack, an aeration assembly and a carrier allowing microorganisms to be attached are arranged on the rack, the aeration assembly comprises an aeration pipe and a draught fan, the carrier is arranged above the aeration pipe, a heating assembly used for heating water and a buoyancy structure are further arranged on the rack, and the buoyancy structure can at least enable the draught fan to be located above the water surface. According to the utility model, a water body in which the water treatment device is positioned can be heated through the heating assembly; therefore, the activity of microorganisms in a low-temperature water environment can be activated; adsorption of large amounts of microorganisms by a carrier, nitrification and denitrification can be carried out on the polluted water body through microorganisms; according to the water treatment device disclosed by the utility model, pollutants such as COD(Chemical Oxygen Demand)