The invention discloses a multi-stage A / O biological
nitrogen removal device and a multi-stage A / O biological
nitrogen removal method based on shortcut
nitrification-anaerobic
ammonia oxidation of
municipal sewage, and belongs to the field of
sewage biological treatment. The device mainly consists of an SBR (
styrene butadiene rubber) carbon removal reactor, a middle water tank, a multi-stage A / P
nitrogen removal reactor and a
sedimentation tank, wherein domestic
sewage firstly enters the SBR reactor to aerate to remove part of organic substances in
raw water, and then enters the A / O reactor to realize shortcut
nitrification-anaerobic
ammonia oxidation by virtue of alternating aerobic / anoxic reaction.
Sludge in a secondary
sedimentation tank flows back to a first-section anoxic zone, so that nitric nitrogen in the flowed-back
sludge can be reduced by utilizing COD (
chemical oxygen demand) in
raw material while the concentration of
sludge in the A / O reactor is guaranteed. According to the multi-stage A / O biological
nitrogen removal device, shortcut
nitrification and anaerobic
ammonia oxidation reaction of the domestic
sewage are realized by utilizing low-
oxygen aeration and bio-contact oxidation, so that the
aeration rate is low, and the
sludge yield is low; and moreover, an external
carbon source is not required to add, so that the multi-stage A / O biological
nitrogen removal device has the characteristics of energy saving and consumption reducing, improves the stability of the reactor, and is convenient to operate.