A fast start-up method for an mbbr-based high-efficiency autotrophic denitrification system

Abstract

A quick start method for an MBBR-based efficient autotrophic nitrogen removal system. Denitrification is coupled to single-stage autotrophic nitrogen removal. A denitrification pool (2) is preposed, and autotrophic nitrogen removal outlet water returns. In a first stage, the removal of a nitrate and an organic matter is implemented, and in a second stage, autotrophic nitrogen removal is implemented. Three running modes, which are respectively a parallel running mode, a dual series A running mode, and a dual series B running mode, are implemented. Water outlet directions of four reaction cells are controlled by a communication valve to implement the serial, parallel, or independent running of the reaction cells. The quick start of an autotrophic nitrogen removal process is implemented by an inoculation mode, a fed-batch mode, or the like. The method implements different process arrangement forms according to treatment requirements, and has advantages of a small inoculation ratio, quick start, high nitrogen removal efficiency, good tolerance for an organic matter in inlet water, or the like.

Description

technical field [0001] The invention belongs to the technical field of wastewater biological denitrification, and in particular relates to a quick start method of an MBBR-based high-efficiency autotrophic denitrification system. Background technique [0002] In the 1990s, when the phenomenon of anammox was discovered, people realized a new type of autotrophic denitrification process. body, carbon dioxide is the main carbon source, and ammonia nitrogen is oxidized into nitrogen. Because the traditional biological denitrification process often limits the denitrification performance due to the lack of carbon source when dealing with wastewater with high ammonia nitrogen and low C / N, it is necessary to add additional organic matter. , thus increasing the operating cost and easily causing the risk of secondary pollution, which is not conducive to the safe and economical operation of the system. Compared with the traditional nitrification and denitrification process, the autotroph...

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Problems solved by technology

[0002] In the 1990s, when the phenomenon of anammox was discovered, people realized a new type of autotrophic denitrification process. body, carbon dioxide is the main carbon source, and ammonia nitrogen is oxidized into nitrogen. Because the traditional biological denitrification process often limits the denitrification performance due to the lack of carbon source when dealing with wastewater with high ammonia nitrogen and low C / N, it is necessary to add additional organic matter. , thus increasing the operating cost and easily causing the risk of secondary pollution, which is not conducive to the safe and economical operation of the system. Compared with the traditional nitrification and denitrification process, the autotrophic denitrification process has more advantages. First, the autotrophic denitrification process has more advantages. Anaerobic ammonium oxidation reaction requires partial nitrosation as a pretreatment process. According to its stoichiometric relationship, it can theoretically save 62.5% of feeding power consumption, and it does not need to add additional organic carbon sources, saving 100% of the cost of external carbon sources. In addition, the sludge output is less, which saves the sludge disposal cost. Finally, it can not only reduce the excessive emission of greenhouse gases such as carbon dioxide, but also consume carbon dioxide. However, the theoretical total nitrogen of the autotrophic denitrification process The removal rate is 89%, and it may be difficult to ensure that the effluent reaches the standard for projects with high requirements for effluent total nitrogen

Although the inoculation rate of this technology is low and the startup time is fast, the NH removed by the system in the stable phase 4 + -N and generated NO 3 - The ratio of -N is 8%-15%, which has a certain gap with the chemical ratio (11%). Generally speaking, the system feed water contains a certain amount of BOD 5 It will lead to the occurrence of denitrification phenomenon and cause the ratio to be too small, and the existence of certain nitrite oxidizing bacteria (NOB) in the system will make the ratio too large. It is worth noting that the existence of NOB will compete with AnAOB for nitrous acid The salt matrix makes AnAOB lack a suitable matrix ratio, causing the system to collapse; in addition, the high concentration of ammonia nitrogen in the influent water used by this technology and the large amount of water lead to a high total nitrogen removal load, but the concentration of ammonia nitrogen in the effluent still reaches about 150 mg / L, which cannot be approached. High processing requirements, need other processes to continue processing

[0009] CN108083581A discloses a low-energy autotrophic denitrification municipal sewage treatment system and method, which adopts the form of serial anaerobic decarburization-autotrophic denitrification to first inoculate the residual sludge of the sewage treatment plant to start the anaerobic carbon removal reactor, and the anaerobic decarbonization reactor involved The start-up process of the oxygen decarbonization reactor takes 60-90 days, and the subsequent start-up process of the autotrophic denitrification reactor needs to inoculate the whole pool with 3000 mg / L anammox sludge for early anaerobic start-up, and artificially distribute water to meet the anaerobic requirements. Ammonia oxidizing bacteria substrate requirements, the reactor start-up process takes 90-120 days, and the whole process starts up 150-210 days. The pre-anaerobic decarbonization tank of this method uses a sludge system, and it is easy for the sludge to enter the post-treatment system after long-term operation. It affects the whole process, and sludge bulking is prone to occur. In addition, this method requires too much anammox bacteria, making inoculation difficult and difficult to achieve long-term large-scale expansion of multiple projects. The manual water distribution in the early stage was successfully started. There is a certain risk of whether the anammox strains can adapt to the actual wastewater

This method also has too much demand for provenance microbial biomass, which is difficult to meet the start-up of large-scale engineering projects, and the start-up process is water distribution operation, so it is impossible to predict whether the cultivated autotrophic denitrification functional microorganisms can use the actual engineering water quality, and the sponge filler can be used in actual projects. It is easy to wear during operation, and when the biofilm forms a certain thickness, it is prone to clogging, which affects mass transfer or the filler becomes heavy and hinders fluidization.

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