The invention belongs to the field of
water environment protection, and particularly provides a
system and method of low-carbon-source town
sewage biological
denitrification by adopting a push-flow-type anoxic tank, and belongs to the field of integration of
activated sludge and
biological membrane processes. The method is an important improvement based on an anoxic-aerobic biological
denitrification process. An anoxic tank is transformed into the push-flow-type reaction tank and is divided into three to four sections; an elastic filler is added into an anoxic reactor to maintain a high
sludge concentration, and a relatively long
hydraulic retention time is adopted in the anoxic tank. In the anoxic tank, a push-flow reaction mode that three to four
complete mixing reactors are connected in series is actually carried out. The method is suitable for improving a conventional biological
denitrification process (the denitrification principle is based on combination of anoxic denitrification-aerobic
nitrification), and the requirement on the carbon-
nitrogen ratio of
sewage can be reduced to 3.0-3.2 while the denitrification rate of the conventional process can be maintained and the denitrification rate is slightly improved. Compared with the conventional biological
denitrification process, the method has the advantages that only the anoxic tank needs to be transformed, and the method is suitable for upgrading and modifying the existing process. According to the method disclosed by the invention,
aeration energy consumption is reduced, and a supplementary
carbon source is saved or even cancelled, so that operation cost is relatively low, and good economical efficiency is achieved.