The invention relates to the technical field of
sewage treatment, in particular to a low-
carbon nitrogen and
phosphorus removal
sewage treatment system, a
sewage treatment method and application thereof. The
sewage treatment system comprises a pretreatment unit, an adsorption tank, a mid-
sedimentation tank, a biochemical tank, a secondary
sedimentation tank and an anaerobic
hydrolysis acidification tank; the biochemical tank comprises an anaerobic tank, an anoxic tank and an aerobic tank; the anaerobic
hydrolysis acidification tank is provided with a VFAs-containing supernate outlet communicated with the anaerobic tank; the mid-
sedimentation tank is provided with an adsorbed
sludge outlet and a sewage outlet, the adsorbed
sludge outlet is communicated with the adsorption tank and the anaerobic
hydrolysis acidification tank, and the sewage outlet is communicated with the anaerobic tank; the secondary sedimentation tank is provided with a biological
sludge outlet and a water outlet, and the biological sludge outlet is communicated with the anaerobic tank and the anaerobic hydrolysis acidification tank. According to the
sewage treatment system, denitrifying
phosphorus-accumulating
bacteria,
nitrifying bacteria and hydrolytic acidification
bacteria can be cultured in different sludge systems, and the contradiction between the denitrifying
phosphorus-accumulating
bacteria, the
nitrifying bacteria and the hydrolytic acidification bacteria on substrate competition and sludge age is solved; and the anaerobic hydrolysis acidification tank is arranged to recycle a
carbon source in the sewage, so that the
advantage of low carbon is achieved.