EH-BFB biochemical denitrification dephosphorization technique

Abstract

The invention relates to a biological treatment method for removing nitrogen and phosphorus of sewage, and the biological treatment method comprises the processes of expansion hydrolysis, pre-denitrification reaction, aerobic reaction, sedimentation and separation, etc. A hydrolysis tank is utilized to replace a traditional tank during the expansion hydrolysis process, a pressure water distributor and a stirring device are further arranged, the biological treatment method does not only have good anaerobic environment and adequate retention time to ensure the phosphorus release, but can also more effectively convey phosphorus accumulating organisms after the full phosphorus release into the aerobic reaction to carry out the phosphorus absorption; suspended biological fillers are added during the aerobic reaction process for forming an aerobic biological fluidized bed, thereby fixing nitrifying bacteria and solving the sludge age contradiction for removing the nitrogen and the phosphorus; at the same time, the fillers form a plurality of micro-A / O nitrogen removal systems, thereby separating microbes with the different sludge ages and also maintaining the simple characteristic of the conventional A<2> / O technology; the biological treatment method does not use the chemical phosphorus removal method and only uses the biological treatment method for solving the contradiction for removing the nitrogen and the phosphorus in the traditional technology and simultaneously achieving the standards that TN is not more than 15mg / L and TP is not more than 0.5mg / L.

Description

technical field [0001] The invention relates to a sewage treatment method, in particular to a biological treatment method mainly used for denitrification and dephosphorization of urban sewage or domestic sewage. Background technique [0002] At present, the surface water system of rivers and lakes is seriously polluted, and large-scale "water blooms" often occur. This is directly related to the high content of nitrogen and phosphorus in the water body. The influx of nitrogen and phosphorus elements into water bodies mainly comes from untreated urban sewage and sewage that has no effect of nitrogen and phosphorus removal after treatment. [0003] The treatment objects of urban sewage treatment plants include COD (BOD5), SS and nutrients such as nitrogen and phosphorus. As far as denitrification and phosphorus removal are concerned, due to the different requirements of their respective processes, there is a certain contradictory relationship between them. Applying conventio...

AI Technical Summary

Problems solved by technology

Obviously, there is a contradiction between nitrifying bacteria and phosphorus accumulating bacteria in the control of sludge age. If the sludge age is too high, it is not conducive to the removal of phosphorus; if the sludge age is too low, nitrifying bacteria cannot survive and excessive sludge will affect subsequent sludge treatment

In the same process, the denitrification effect is good, and the phosphorus content in the sewage is generally greater than 1.0mg / L. In order to meet the discharge standards, a first-level chemical phosphorus removal is required, and the amount of sludge increases, causing secondary pollution.

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