The invention relates to a full-automatic dissolved air floatation device which comprises an air floatation box body, a regulation weir, a water inlet, a water outlet, a
sewage outfall, a dissolved air tank, a mud scraper and a
slag collection groove, wherein the mud scraper is arranged at the upper part of the air floatation box body; the dissolved air floatation device further comprises a dissolved
air pump and a water receiving and air removal
system; the dissolved
air pump is arranged on the outer side of the lower part of the air floatation box body; one end of the dissolved
air pump is connected with the dissolved air tank, and the other end of the dissolved air pump is connected with a
reflux pipe and communicated with the inner part of the air floatation box body; and the water receiving and air removal
system is arranged at the lower part of the air floatation box body and connected with the regulation weir. The full-automatic dissolved air floatation device improved on the basis of a traditional dissolved air floatation device has the advantages that the dissolved air pump is adopted by the air floatation device to replace a pressure pump, an
air compressor, a jet device, a
high pressure dissolved air tank, an air-water mixer, a release head, and the like of the traditional device, so that the problems of
complex system, operation
instability and large
air bubble overturn of the traditional device are overcome; and the
reflux pipeline is scientifically arranged at the inner part of the equipment, and the internal water receiving and air removal
system is additionally arranged, so that
air bubble entrainment of outlet water, which influences subsequent treatment, is avoided.