A method for biological denitrification of domestic sewage and a method for starting the system

Abstract

A biological denitrification method for domestic sewage and a system start-up method relate to a sewage treatment method and a system start-up method. The denitrification method of the present invention: the domestic sewage is passed into the activated domestic sewage biological denitrification treatment system for denitrification treatment; during the operation process of the denitrification treatment, DO is controlled to be <0.5mg / L. Start-up method: 1. Put the denitrified granular sludge in the reaction zone of the EGSB reactor, pass it into the artificial water inlet operation that is considered to be set, and control the DO to gradually increase the NLR in stages; 2. Put the simulated sewage into the operation until the NOB is relatively The abundance is less than 1%; 3. The actual domestic sewage is introduced to realize the stable operation of the complete autotrophic denitrification process. The biological denitrification method for domestic sewage of the present invention has low operation cost and low start-up cost, and is convenient for upgrading and transformation of sewage plants, and is easier to realize. Moreover, the method of the invention is not affected by temperature fluctuations of domestic sewage, and also has excellent denitrification effect at a relatively low temperature of 10-28°C.

Description

technical field [0001] The invention relates to a sewage treatment method and a system startup method. Background technique [0002] In view of the nitrogen source pollution in urban sewage, traditional biological denitrification processes based on nitrification and denitrification processes are often used for treatment. These processes have been widely used in urban sewage treatment. However, with the improvement of wastewater discharge standards, the traditional denitrification process has also exposed its own shortcomings. For example: the capital construction cost of the multi-stage treatment system is high; the denitrification process requires a large amount of carbon sources, which increases the operating cost of the water plant; the excess sludge yield is high, which further increases the treatment cost; more greenhouses are generated during the denitrification process. gas, not conducive to sustainable development. [0003] Anammox (anaerobic ammonium oxidation) pr...

AI Technical Summary

Problems solved by technology

On the one hand, the concentration range of ammonia nitrogen in domestic sewage is generally 30-50mg / L, and the concentration of ammonia nitrogen is low. Under the low concentration of ammonia nitrogen, it is difficult for free ammonia to reach the concentration level that can be suppressed, and the nitrosation process is difficult to stabilize, and the rapid proliferation of NOB will Destroy the reaction pathway of autotrophic denitrification and oxidize the NO obtained by AOB 2 - -N is directly converted to nitrate nitrogen (NO 3 - -N); on the other hand, lower temperature (10-28°C) and low substrate concentration are not conducive to the proliferation of fully autotrophic denitrification bacteria, especially AnAOB, and the overall denitrification efficiency will become worse

Therefore, it is particularly important to ensure the high efficiency and stability of AOB and AnAOB activities while also achieving effective inhibition of NOB, but the existing technology cannot achieve the above goals

[0005] At the same time, it is inevitable that a certain concentration of organic matter will remain in domestic sewage, and heterotrophic bacteria will inevitably appear in the water treatment system. More stable operation is also a problem to be solved

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