Sewage treatment process for effectively denitrifying by utilizing endogenous respiration

Abstract

The invention discloses a sewage treatment process for effectively denitrifying by endogenous respiration, which comprises the following steps: treating sewage by an anaerobic tank, an anoxic tank, amicro-aerobic zone tank, an aerobic tank and a secondary sedimentation tank in sequence, feeding the sewage from the upper end of the anaerobic tank, making the sewage with the anoxic tank by the anaerobic tank and then feeding into the micro-aerobic tank from the middle part of the anoxic tank, wherein the micro-aerobic tank is communicated with the bottom of the aerobic tank, sewage in the micro-aerobic tank enters the aerobic tank from the bottom after reaction, the sewage in the aerobic tank overflows into the secondary sedimentation tank after short retention, and the sewage is dischargedfor advanced treatment after sedimentation. The addition of salt is reduced, the secondary pollution is reduced, the DO control is relatively low, the electric charge is saved, the process control isrelatively easy, and large-scale replication can be realized.

Description

technical field [0001] The invention relates to the field of sewage treatment, in particular to a sewage treatment process for effectively denitrifying domestic sewage with a low carbon-to-nitrogen ratio by utilizing endogenous respiration. Background technique [0002] Biochemical treatment of sewage is mostly based on the traditional mechanism of nitrogen and phosphorus removal. Nitrification process, including nitrification and denitrification; nitrification, that is, autotrophic nitrifying bacteria (AOB, NOB) under aerobic conditions, NH4+-N→NO2--N; denitrification, that is, denitrifying bacteria Under hypoxic conditions, NOX- is used as electron acceptor and organic matter is used as electron donor, NO3--N→NO2--N→N2. It can be seen that for nitrogen removal, the core includes three types of bacteria. Nitrifying bacteria, denitrifying bacteria, and nitrifying bacteria belong to autotrophic bacteria, which are strictly aerobic and have a low specific growth rate; most de...

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Problems solved by technology

Relevant studies have shown that when the BOD5 / TKN in the wastewater influent is ≥ 4-6 (converted into COD / TKN ≥ 6-10), it can be considered that the denitrification carbon source is sufficient, while the general domestic sewage influent generally has COD / TKN ≤ 4, it belongs to the serious shortage of carbon sources, and a large amount of carbon sources need to be invested outside

4) Under the condition of insufficient carbon source, the existing A2 / O process often fails to meet the requirements of total nitrogen compliance. A large number of sewage treatment plants carry out advanced treatment, and add denitrification deep bed filter facilities for deep denitrification. The construction cost and operating cost increase a lot

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