Device for treating freshwater aquaculture sewage

The utility model discloses a device for treating freshwater aquaculture sewage, and belongs to the technical field of environmental engineering. Comprising a composite biological aerated filter, a freshwater aquaculture sewage tank, a co-metabolism substrate tank, a phosphorus removal agent tank, a water outlet tank, an air compressor and an air pump, the composite biological aerated filter sequentially comprises a sludge discharge port, a sludge hopper, a water inlet area, a backwashing aeration head, a non-aeration area, a membrane aeration area, a membrane aeration assembly, a bubbling aeration area, a water outlet area and a water outlet from bottom to top, sewage sequentially passes through the non-aeration area, the membrane aeration area and the bubbling aeration area which are all filled with ceramsite, and a phosphorus removal agent is put into a phosphorus removal agent tank to enhance the phosphorus removal effect. According to the utility model, the composite biological aerated filter with the no