System and method for deep nitrogen and phosphorus removal and resource recovery of AAO-BCO process

Abstract

The invention discloses a system and method for deep nitrogen and phosphorus removal and resource recovery of an AAO-BCO process. The system comprises an AAO-BCO system which is formed by sequentiallyconnecting a raw water tank, a water inlet pump, an AAO reactor, a middle settling tank, a middle water tank, a middle water inlet pump, a biological contact oxidation tank and a settling region, wherein a mud discharging pipe at the bottom of the middle settling tank and the bottom of the settling region are connected with a mud storage tank through a mud discharging valve I and a mud discharging valve II, respectively, the mud storage tank is sequentially connected with a fermentation tank, a nitrogen and phosphorus recycling tank and a liquid storage tank, the top of the fermentation tankis connected with an alkali liquid dosing tank through a lifting pump II, and a mud discharging valve IV is arranged at the bottom of the fermentation tank; and the top of the nitrogen and phosphorusrecycling tank is connected with a magnesium salt solution dosing tank through a lifting pump I, a mud discharging valve III is arranged at the bottom of the nitrogen and phosphorus recycling tank, and the liquid storage tank is connected with the raw water tank through a lifting pump III. According to the system and the method, the deep nitrogen and phosphorus removal and the resource utilizationof sludge of the AAO-BCO process are realized under a low C / N sewage condition.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a system and method for realizing deep denitrification and dephosphorization of AAO-BCO process and resource recovery. Background technique [0002] At present, urban sewage plants at home and abroad mostly use biological methods for nitrogen and phosphorus removal. The available dissolved organic matter in raw water, especially the content of short-chain fatty acids, has a significant impact on the microbial nitrogen and phosphorus removal. When the concentration of organic matter in the influent is low, the amount of short-chain fatty acids cannot meet the needs of denitrifying bacteria and phosphorus-removing bacteria. The influent C / N of urban sewage in my country is generally low, which is not conducive to the operation of nitrogen and phosphorus removal processes, and usually requires additional carbon sources such as acetic acid. If the organic acid produced in ...

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Problems solved by technology

[0004] The AAO-BCO process adopts the combination of activated sludge and biofilm, which solves the competitive contradiction among the various bacterial groups in the traditional process, and realizes a dual-sludge system mainly based on denitrification and phosphorus removal, especially in low C / N The conditions are favorable for denitrifying phosphorus accumulating bacteria (DPAOs) to become the dominant bacteria, but the carbon source in this process still limits the effect of nitrogen and phosphorus removal

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