A kind of recovery method of simultaneous nitrification anammox and denitrification process

Abstract

The invention discloses a recovering method of a synchronous nitrosation-anaerobic ammonia oxidation and denitrification process, and belongs to the field of advanced wastewater treatment. In the SNAD (Synchronous Nitrosation-Anaerobic ammonia oxidation and Denitrification) process, NOB (Nitrite Oxidizing Bacteria) can be greatly proliferated due to inappropriate operation, and the denitrification effect of the system is continuously decreased and even broken down. According to the recovering method disclosed by the invention, (1) an aeration rate is adjusted to always maintain the dissolved oxygen concentration in the reaction stage to be under 0.3 mg / L; (2) the hydraulic retention time (HRT) is shortened, and the effluent of the reactor always contains NH4<+>-N (greater than or equal to 10 mg / L); (3) an NaOH solution is added to the inflow, and the pH value of the inflow is increased to 7.8-8.0; (4) an inorganic carbon source is artificially added to the inflow, and the ratio of the basicity to the ammonia-nitrogen concentration is maintained to be 10 (gCaCO3 / Gnh4<+>-N) above. The strategies are maintained to be continuously operated until the characteristic ratio (namely the ratio of a total nitrogen removal amount to the generated nitrate-nitrogen amount) is greater than 20, the total nitrogen removal rate is greater than 75%, and the strategies are continuously operated for more than 10 cycles, and then the synchronous nitrosation-anaerobic ammonia oxidation and denitrification process is considered to be effectively recovered.

Description

technical field [0001] The invention belongs to the field of advanced sewage treatment. In particular, it relates to a recovery method for a simultaneous nitrosation-anammox and denitrification (SNAD) process. It is suitable for sewage and wastewater treatment with low carbon-to-nitrogen ratio. Background technique [0002] In the late 1980s, Mulder et al. found that in addition to the well-known denitrification reaction, there was an unknown reaction to make ammonia nitrogen disappear in the biological denitrification fluidized bed reactor, and predicted the anaerobic ammonium oxidation reaction (ANAMMOX) The existence of anammox bacteria was proved more than 10 years later. Third et al. proposed the CANON (completelyautotrophic nitrogen removal over nitrite) process in 1999, which is a single-stage full autotrophic nitrogen removal process. This process is based on the principle of short-range nitrification and anaerobic ammonium oxidation reaction. Compared with the tr...

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Problems solved by technology

[0007] However, in the application process, the SNAD process often results in a large number of nitrite oxidizing bacteria (NOB) in the system due to improper operation, equipment failure and other reasons, resulting in NO in the effluent. 3 — N increases, the total nitrogen removal rate decreases, and the reactor changes to the direction of full nitrification and denitrification, which eventually leads to the collapse of the SNAD process

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