Integrated treatment plant for sewage from biological removal of nitrogen

Abstract

The present invention is an improvement on anoxic (facultative anaerobic)-aerobic water treatment device for biological nitrogen removal. The adjacent partition arrangement forming inner circulation is that an anoxic zone is arranged on the outer periphery of the aerobic zone; a gas-liquid separation diversion inclined plate is arranged above an overflow circumference on the upper part of the aerobic zone; and an inlet water distribution zone is disposed above the anoxic zone, and extends into a water distributor below the liquid surface of the anoxic zone for water distribution. The structure effectively overcomes or reduces the disadvantage of oxygenation caused by water inlet and reflux in the anoxic zone in the prior art, reduces or restricts the water inlet and oxygenation into the anoxic zone, helps to control the dissolved oxygen in a low required range in the anoxic zone, and satisfies the requirements of hypoxia of denitrifying bacteria, thereby increasing the effect of denitrification and nitrogen removal. The plant can omit additional power upgrade reflux and an anoxic zone mixing device, thereby reducing the energy consumption.

Description

technical field [0001] The present invention is an improvement to the anaerobic (concurrently) oxygen-aerobic water treatment device mainly used for biological denitrification, especially relates to an internal circulation type, which does not need to increase the power additionally, and the power consumption is small, and the reflux liquid and the water distribution are relatively The anoxic pool has less oxygen increase, which is beneficial to maintain the low DO in the anoxic pool and the integrated biological denitrification sewage treatment device. Background technique [0002] The eutrophication of water body has attracted more and more people's attention, and the sewage treatment standard has also been improved. The purpose of sewage treatment is no longer just to remove BOD and SS. The removal of nutrients such as nitrogen and phosphorus has become an important control target of sewage treatment. The anoxic-aerobic (A / O) biological denitrification technology develope...

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Problems solved by technology

Anoxic / aerobic biological denitrification with this structure, the actual denitrification effect is not very high, so that the superiority of anoxic / aerobic biological denitrification cannot be fully exerted, the main disadvantages are: the construction of a sub-pool, large footprint , the investment cost is high; the backflow of the second aerobic pool to the anoxic pool needs to increase the backflow boost power, and the return flow of the backflow liquid is usually large, for example, the backflow ratio is up to about 200%, and in order to make the backflow liquid and the influent water and anoxic The pool sewage is fully mixed, and it is necessary to add a stirring device in the anoxic pool, so the auxiliary power consumption is relatively large; the three-anoxic denitrification effect must be carried out at a low dissolved oxygen (DO) such as DO≤0.5mg / l, and the objective For aerobic nitrification, higher DO (2.0-4.0mg / l) is required, and a large amount of reflux liquid from the aerobic tank directly enters the anoxic tank, and the anoxic tank is stirred and mixed, and the water in the anoxic tank adopts a drop type , all three factors will lead to an increase in DO in the anoxic tank (the last two are air), so it is difficult to maintain the low DO required in the anoxic tank, thereby reducing the denitrification and denitrification capacity, which is the cause of denitrification The main reason for the unsatisfactory effect; the four nitrification-denitrification mainly adopts the mud method of activated sludge, which produces a large amount of excess sludge, and sludge treatment is required, which increases the operating cost

Although the Chinese patent CN201313854 adopts the method of setting the water inlet at the bottom of the aerobic zone to reduce the oxygen increase caused by the influent, it cannot allow the denitrifying bacteria in the anoxic zone to preferentially obtain the high carbon source of the influent, which also affects the performance of biological denitrification; The water flows directly to the aerobic zone, which will easily cause the treated sewage to directly enter the sedimentation tank short-circuit flow during the air lifting process; at the same time, the sedimentation tank is set above the aerobic zone, which complicates the overall structure of the equipment and is not conducive to management and maintenance

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