Method and system for separating biomass from activated sludge and application

Abstract

The invention discloses a method and system for separating biomass from activated sludge and application. The method comprises the following steps: carrying out high-temperature reaction on alkaline thick slurry and activated sludge to be treated, and rapidly cooling the activated sludge mixture after the high-temperature reaction to 60-90 DEG C. Compared with an existing 'flash evaporation' cooling mode, the method has advantages that the temperature after cooling is greatly reduced, and the phenomenon that after the 'flash evaporation' cooling mode is adopted, the materials are further decomposed to generate a large amount of ammonia nitrogen after the reaction is completed, and the ammonia nitrogen is volatilized and separated out to form odor is avoided. Meanwhile, the use of alkaline thick slurry is reduced from the source, so that the alkaline concentration in the mud cake and the filtrate is reduced, the application of the mud cake is expanded, and the damage of the filtrate with overhigh pH to plants is avoided. The low reaction temperature is adopted, and energy consumption is reduced while it is guaranteed that harmful microorganisms are effectively killed. In addition, due to the reduction of the reaction temperature, a large amount of active nitrogen is preserved.

Description

technical field [0001] The invention relates to the technical field of sludge treatment, in particular to a method, system and application for separating activated sludge biomass. Background technique [0002] The sludge produced by urban sewage treatment plants has not been effectively treated for a long time, and the problem of environmental pollution has become increasingly prominent; the sanitary landfill and dry incineration treatment methods adopted in recent years not only consume a lot of land and energy, but also still have the risk of polluting the environment. At present, emerging technologies for sludge treatment aimed at improving the efficiency of "recycling" have been produced. For example, using hot alkali hydrolysis method supplemented by flash evaporation to extract substances containing proteins and polypeptides by breaking the wall of microbial cells, and preparing liquid raw materials for use as Agricultural fertilizers. The prior art is described as fo...

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Problems solved by technology

But its current obvious disadvantages: (1) The reaction mechanism is single, completely dependent on alkali-thermal reaction, the efficiency is low, and because of the low temperature difference, the effect of flash breaking the wall is not obvious; (2) The alkali-thermal conditions are difficult to balance, lime and Sludge is added to the reaction vessel separately, completely relying on anchor type or anchor slurry type stirring (low speed) mixing, the uniformity of alkalinity and temperature is restricted; (3) The reaction time is long, after reaching the design temperature, the reaction time reaches 240 minutes, and the reaction The cost and energy consumption of the container are high; (4) the mass percentage of CaO is between 5% and 5.5%, and the nitrogen content in the filtrate is low, which is 2000-2300mg / L. After the solid-liquid separation, excessive lime enters In the mud cake, on the one hand, the pH value of the filtrate is too high, which will damage the crops; on the other hand, the Ca(OH) in the mud cake 2 (5) The reacted material is quenched by "flash evaporation", which has a good quenching effect, but it will cause a large amount of ammonia nitrogen to be released, The formation of odor pollutes the environment and reduces the total nitrogen in the filtrate

In addition, the current flash evaporation process can only quickly reduce the reacted material from 140°C to 100°C, and cannot completely prevent organic nitrogen from continuing to be converted into ammonia nitrogen; (6) The existing process chain is long, the equipment is numerous, and the investment is high , Occupy a large area, relatively complex maintenance and management

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