Apparatus and method for biological sewage treatment with effects of nitrogen and phosphorus synchronous removal and sludge reduction

Abstract

Disclosed are an apparatus and a method for biological sewage treatment with effects of nitrogen and phosphorus synchronous removal and sludge reduction. The apparatus comprises a water inlet pipe 1, an anaerobic tank 2, a median settling tank 3, an intermediate water tank 4, a biological aerated filter (BAF) 5, an anoxic tank 6, a rear aeration tank 7, a secondary settling tank 8 and a water outlet pipe 9 connected in sequence. The method for biological sewage treatment includes mixing raw water and P-enriched returned sludge in the anaerobic tank, utilizing denitrifying phosphorus removing bacteria (DPBs) to absorb volatile organic acid (VFA) and store the same in the form of poly Beta-hydroxybutyric acid (PHB) while releasing a great quantity of phosphorus; carrying out removal of residual COD and nitrification of nitrogen by the BAF, delivering nitrification liquor of the BAF and sludge of the median settling tank into the anoxic tank together, and utilizing the DPBs in the anoxic tank to carry out denitrifying phosphorus-uptake by taking in-vivo PHB as energy source and carbon source and taking NO3<-> as an electron acceptor; removing residue phosphorus and blowing off nitrogen gas to avoid sludge floating in the rear aeration tank, delivering the mixture liquid into the secondary settling tank, discharging supernate, returning a part of sludge containing a great quantity of DPBs and discharging residual sludge. By the method, the problem of conflict between nitrogen removal and phosphorus removal is solved, quality stability of outlet water is guaranteed, and yield of sludge is low.

Description

technical field [0001] The invention belongs to the field of sewage treatment, in particular to a sewage biological treatment device and method for synchronous nitrogen and phosphorus removal and sludge reduction. Background technique [0002] A large amount of excess sludge produced in aquatic biological treatment has caused great pressure on the environment, and its treatment and disposal costs are high, which has become a bottleneck restricting the development of the sewage industry. In this context, sludge reduction technology has become a hot research topic in the sewage industry. The so-called sludge reduction refers to the use of physical, chemical and biochemical means to minimize the amount of biological solids discharged from the entire sewage treatment system. However, the current sludge reduction technologies have disadvantages. The physical method has economic problems, the chemical method has environmental safety problems, and the biochemical method has the pr...

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Problems solved by technology

[0005] The purpose of the present invention is that the purpose of the present invention is to propose a sewage biological treatment method for synchronous denitrification and phosphorus removal and sludge reduction for the respective defects of the current sludge reduction and BAF, combining activated sludge and BAF to form The dual-sludge system can not only solve the problem of poor BAF biological phosphorus removal effect, but also realize nitrogen and phosphorus removal while reducing the amount of sewage treatment sludge

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