Device and method for treating low-C/N (carbon/nitrogen) ratio urban sewage by an anoxic/aerobic SBR-DEAMOX (denitrifying ammonium oxidation) denitrification process

Abstract

The invention provides a device and method for treating low-C / N (carbon / nitrogen) ratio urban sewage by an anoxic / aerobic SBR-DEAMOX (denitrifying ammonium oxidation) denitrification process. One part of the urban sewage firstly enters an anoxic / aerobic SBR reactor and is subjected to pre-denitrifying and nitrifying reaction; and the produced nitrifying liquid is mixed with the other part of raw sewage, and the mixture enters a partial DEAMOX reactor for denitrification. The method comprises the following steps that: 65-85% of the raw water enters the anoxic / aerobic SBR reactor; the pre-denitrifying process is performed by use of the carbon source in the raw water to reduce the residual NO3<->-N of the system in the previous cycle; the NH4<+>-N is oxidized into NO3<->-N by aeration; the nitrifying liquid and 15-35% of the raw water together enter the DEAMOX reactor; and by taking the NO2<->-N produced by partial denitrifying as an electron acceptor, the NH4<+>-N in the raw water generates N2 through anaerobic ammonium oxidation reaction to realize deep denitrification of low-C / N ratio urban sewage. The technology makes full use of the carbon source in the raw water, does not need an external carbon source, saves energy consumption of aeration, and is an economical and efficient new means for solving the problem in the denitrification of low-C / N ratio urban sewage.

Description

technical field [0001] The invention relates to a low-energy-consumption method for treating urban sewage with a low carbon-nitrogen (C / N) ratio, which belongs to the technical field of sewage biological treatment. Specifically, the raw water is divided into two parts, and one part enters an anoxic / aerobic SBR reactor. Make full use of organic matter in raw water through pre-denitrification, followed by aeration for nitrification, nitrification liquid and another part of raw water enter the partial denitrification coupling anaerobic ammonium oxidation (DEAMOX) reactor, and use a small amount of organic matter in raw water to generate through partial denitrification Nitrite nitrogen, and then synchronously with ammonia nitrogen in the raw water, through the anaerobic ammonium oxidation reaction to achieve the removal of water nitrogen in the sewage. The invention fully utilizes the carbon source in the raw water without adding an external carbon source, reduces the oxygen consu...

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Problems solved by technology

The realization of short-cut nitrification is mainly through the limitation of dissolved oxygen, inhibition of free ammonia and high temperature operation, so that the nitrification reaction can only proceed to NO 2 - The -N step, however, is limited in the practical application of treating low C / N ratio urban sewage, mainly due to the difficulty in maintaining the stability of nitrite accumulation, the difficulty in raising the temperature of sewage, and economic inappropriateness.

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