Denitrifying dephosphorization device and method of A2/O-biological aerated filter (BAF)

Abstract

The invention discloses denitrifying dephosphorization device and method of an A2 / O-biological aerated filter (BAF), belonging to the technical field of activated sludge and sewage treatment. The device is mainly formed by sequentially connecting a raw water tank (1), an A2 / O reactor (2), a secondary sedimentation tank (3) and a BAF (4). The method comprises the following steps of: elutriating nitrifying bacteria with a long sludge age through shortening the sludge age of A2 / O to 15 days; growing DPAOs (Denitrifying Phosphate Accumulating Organisms), denitrifying bacteria, and the like with a short sludge age in A2 / O activated sludge in a suspension state; growing denitrifying bacteria with a long sludge age on an active biological filler in the BAF in a fixed film form; running the A2 / O reactor under a short sludge age condition for denitrifying denitrification and dephosphatation; running the BAF under a long sludge age condition for nitrifying; and meanwhile, providing enough electron acceptors for an anoxic zone of the A2 / O reactor so as to provide a necessary condition for denitrifying dephosphatation. The invention has stable reliable treatment effect, stable outlet water quality and lower energy consumption.

Description

technical field [0001] The invention relates to a device and method for denitrification and dephosphorization, which belong to the technical field of sewage treatment by activated sludge method, and are suitable for the upgrading and transformation of new sewage plants and old sewage plants, the treatment of municipal sewage and industrial waste water, and scattered rural domestic sewage, etc. Sewage treatment field. Background technique [0002] Excessive discharge of nutrients such as nitrogen and phosphorus is an important cause of "eutrophication" of water bodies, which poses a serious threat to industrial and agricultural production and people's lives. A 2 / O, as the simplest simultaneous denitrification and phosphorus removal process, has a series of advantages such as simple structure, short hydraulic retention time, mature design and operation experience, low control complexity and not easy to produce sludge bulking. main process. However, A 2 The contradiction b...

AI Technical Summary

Problems solved by technology

However, A 2 The contradiction between nitrifying bacteria, denitrifying bacteria and DPAOs in organic load, sludge age and carbon source requirements in / O makes it difficult to simultaneously obtain good nitrogen and phosphorus removal effects in a single biochemical system, which hinders nitrogen and phosphorus removal technology Applications

Biological aerated filter is more and more popular because of its flexible modular design, small footprint, and stable nitrification effect. However, the biological aerated filter has short working cycle, high backwash frequency, and is prone to clogging. Phenomenon

my country's urban sewage naturally has low C / N, coupled with the contradictions in the process itself, resulting in the discharge of more than 95% of urban sewage treatment plants that cannot meet the first-level A discharge of the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002) standard

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