Double-layer biochemical pool

Abstract

The present application relates to sewage treatment equipment technical field, specifically relates to a double-layer biochemical pool, the biochemical pool adopts double-layer civil structure, the lower layer is anoxic zone, the upper layer is pre-anoxic zone, anaerobic zone and aerobic zone, the upper and lower superposition construction, the anoxic zone adopts the form of multichannel culvert, relies on sludge circulating pump and not submersible agitator to realize the anoxic zone large proportion mixed liquor constant circulation flow, has the good flow state of push flow type and complete mixing type, the flow velocity is uniform, avoids the local silt accumulation phenomenon that the conventional single-layer biochemical pool anoxic zone generally exists, the anoxic zone volume utilization rate is high, improves the anoxic reaction efficiency, has the advantages of high treatment efficiency, not easy to silt, reduces the biochemical land area 30-40%.

Description

TECHNICAL FIELD

[0001] The present application relates to sewage treatment equipment technical field, specifically to a double-layer biochemical pool. BACKGROUND

[0002] With the increasing requirements of water environment governance and effluent standards, many domestic municipal wastewater treatment plants are under pressure to expand or upgrade. In the treatment facilities of wastewater treatment plants, the biochemical pool has the largest land area, which often becomes a limiting factor for the construction land area when the wastewater treatment plant is expanded or upgraded, affecting the selection of biochemical treatment process. Among the biochemical treatment processes, A 2 / O series processes such as A / O denitrification process, conventional A 2 / O, improved A 2 / O, inverted A 2 / O, multi-stage A / O process, etc., have the advantages of stable and efficient operation, simple management, are widely favored, and are widely used, and are the preferred process form. In the case of limited area of wastewater treatment plant and the desire to use A 2 / O series biochemical treatment process, how to transform the biochemical pool and save land becomes the top priority. SUMMARY

[0003] Based on the above description, the present application provides a double-layer biochemical pool, which can not only meet the A 2 / O series process by reasonable layout, but also improve the treatment efficiency, reduce the accumulation phenomenon, and greatly reduce the biochemical land area.

[0004] The technical solution of the present application to solve the above technical problems is as follows: a double-layer biochemical pool, comprising upper and lower layers, wherein the lower layer is an anoxic zone, the anoxic zone is in the form of a multi-channel underground channel, and is horizontally baffled, the anoxic zone is provided with an anoxic zone water inlet at the starting end and an anoxic zone water outlet at the end;

[0005] The upper layer is separated into a first region and a second region by a partition wall along the length direction of the biochemical pool, the first region is separated into a pre-anoxic zone and an anaerobic zone by a partition wall two along the width direction of the biochemical pool, and the water outlet of the anaerobic zone is correspondingly arranged with the water inlet of the anoxic zone; the second region is separated into an aerobic zone and an oxygen-consuming zone with one end communicating by a partition wall three along the length direction of the biochemical pool, and the second region is further provided with a sludge circulation tank, and the sludge circulation tank is arranged along the length direction of the biochemical pool with the aerobic zone and the oxygen-consuming zone;

[0006] The sludge circulation tank is provided with a sludge circulation tank water inlet and a sludge circulation tank water outlet at two ends respectively, the sludge circulation tank water inlet is located above the anoxic zone water outlet and is communicated with the beginning end of the aerobic zone, the sludge circulation tank water outlet is communicated with the beginning end of the anoxic zone, the end of the oxygen-consuming zone is connected with the sludge circulation tank through a sludge internal reflux pump, and the end of the aerobic zone is provided with an overflow weir and a water outlet pipe connected to a pool outside; after the anoxic zone end water enters the sludge circulation tank upward, a part of the water flows into the aerobic zone, and the other part of the water is lifted through the sludge circulation pump in the sludge circulation tank and then enters the anoxic zone starting end through the sludge circulation tank water outlet.

[0007] Based on the above technical scheme, the application can be further improved as follows.

[0008] As a preferred embodiment, a partition wall four is arranged in the anaerobic zone along the vertical water inlet direction, and the partition wall four is used to ensure the water flow deflection in the anaerobic zone.

[0009] As a preferred embodiment, the aerobic zone is in a multi-channel form and is arranged in a horizontal water flow deflection manner.

[0010] As a preferred embodiment, the pre-anoxic zone and the anaerobic zone 4 are arranged at the side of the upper second area, the oxygen-consuming zone is located between the aerobic zone and the first area, the sludge circulation tank is located at the end of the aerobic zone and the oxygen-consuming zone and corresponds to the beginning end and the end of the lower anoxic zone, and the sludge circulation tank is arranged close to the pre-anoxic zone.

[0011] As a preferred embodiment, a hole is formed in the partition wall two, the pre-anoxic zone water outlet flows into the anaerobic zone through the hole, and the anaerobic zone water outlet flows into the anoxic zone downward.

[0012] As a preferred embodiment, the lower pool body is further provided with a partition wall five, and the partition wall five is used to ensure the connection of the sludge circulation tank water outlet and the anoxic zone starting end.

[0013] Further, the partition wall five is located below the pre-anoxic zone, the partition wall five is arranged along the width direction of the biochemical pool and forms a flow guide channel with the biochemical pool edge, and the flow guide channel is communicated with the beginning end of the anoxic zone.

[0014] As a preferred embodiment, the oxygen-consuming zone is provided with a submersible mixer.

[0015] As a preferred embodiment, the anoxic zone is provided with a ventilation hole, the ventilation hole penetrates through the anaerobic zone or the aerobic zone to the pool top, is connected with a foul gas collection pipeline, and functions as a manhole.

[0016] Compared with the prior art, the technical scheme of the application has the following beneficial technical effects:

[0017] (1) the biochemical pool adopts double-layer civil structure, the lower layer is anoxic zone, the upper layer is pre-anoxic zone, anaerobic zone and aerobic zone, the upper and lower layers are constructed in a superimposed manner, and have good flow states of push flow type and complete mixing type, are not easy to silt, have reasonable layout, can reduce biochemical land area by 30-40%, and in addition, by additionally arranging pre-anoxic zone and oxygen-consuming zone, the treatment efficiency is higher and better; for secondary treatment of sewage of a certain scale, according to water depth of 6m of anoxic zone and residence time of 6h, or according to water depth of 8m of anoxic zone and residence time of 8h, when the double-layer biochemical pool is used, the saved land area is equivalent to the net land area of the secondary sedimentation tank;

[0018] (2) the anoxic zone adopts a pipe culvert type reactor, adopts a multi-channel underground channel form, relies on a sludge circulating pump instead of a submersible agitator to realize continuous circulation flow of a large proportion of mixed liquid in the anoxic zone, maintains the required non-silt flow rate (the configuration power of the sludge circulating pump is equivalent to that of the submersible agitator), the flow rate is uniform, the local sludge silt phenomenon commonly existing in the anoxic zone of the conventional single-layer biochemical pool is avoided, the volume utilization rate of the anoxic zone is high, and the anoxic reaction efficiency is improved;

[0019] (3) the anoxic zone can be in a sealed and pressurized state, the air holes can be very conveniently connected with the odor collection pipeline, the anoxic zone is an odor source, has the advantages of high odor collection rate and good effect, and can reduce the engineering quantity and investment of deodorization and capping of the anoxic zone. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The upper layer plane schematic diagram of the double-layer biochemical pool provided for the embodiment of the present application is shown in the figure;

[0021] Figure 2 The lower layer plane schematic diagram of the double-layer biochemical pool provided for the embodiment of the present application is shown in the figure;

[0022] Figure 3 The cross-sectional view of the double-layer biochemical pool provided for the embodiment of the present application is shown in the figure.

[0023] In the figure, the components represented by each reference sign are listed as follows:

[0024] 1 inlet pipe, 2 sludge external return pipe, 3 pre-anoxic zone, 4 anaerobic zone, 5 anoxic zone, 6 aerobic zone, 4.1 anaerobic zone water outlet, 5.1 sludge circulating tank, 5.2 sludge circulating pump, 5.3 anoxic zone water inlet hole, 5.4 anoxic zone water outlet, 5.5 air hole, 6.1 oxygen-consuming zone, 6.2 submersible agitator, 6.3 sludge internal return pump, 7 outlet pipe. DETAILED DESCRIPTION

[0025] For the purpose of promoting the understanding of the present application, the present application will be more fully described by reference to the following drawings. The following drawings represent embodiments of the present application. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It is noted that the use of any and all examples, or exemplary language (e.g., "about") provided herein, is intended to help

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0027] It can be understood that the length direction and the width direction described in the present application are only for the convenience of description, and are not used to limit the present application.

[0028] A double-layer biochemical pool comprises an upper layer and a lower layer, and the upper layer and the lower layer are arranged in a stack, preferably, the whole is a rectangular double-layer structure. The lower layer is an anoxic zone 5, the structure of which is shown in Figure 2 The anoxic zone 5 is in the form of a multi-channel underground channel, is arranged in a horizontal zigzag manner, and the starting end of the anoxic zone 5 is provided with an anoxic zone water inlet (corresponding to Figure 1 4.1), and the ending end is provided with an anoxic zone water outlet 5.4.

[0029] Specifically, the anoxic zone 5 is parallelly arranged with a plurality of partition walls, the plurality of partition walls are connected with an inner wall on one side, form a multi-channel underground channel, the cross section is rectangular, is arranged in a horizontal zigzag manner, the width is 2-3 m, and the height is determined according to the design volume of the anoxic zone 5, is generally not less than 2 m, and satisfies the requirement of human maintenance.

[0030] The upper layer mainly comprises a pre-anoxic zone 3, an anaerobic zone 4 and an aerobic zone 6. Specifically, the upper layer is isolated into a first region and a second region by a partition wall one arranged along the length direction of the biochemical pool, the first region is isolated into the pre-anoxic zone 3 and the anaerobic zone 4 by a partition wall two arranged along the width direction of the biochemical pool, and an anaerobic zone water outlet 4.1 is arranged corresponding to the water inlet of the anoxic zone 5.

[0031] The second region is separated into an oxygenated zone 6 and an oxygen depleted zone 6.1 by a partition wall 3 arranged along the length direction of the biochemical tank, the partition wall 3 is actually similar to a baffle partition wall, and a sludge circulation tank 5.1 is further arranged in the second region, the sludge circulation tank 5.1 is used for connecting the start end and the end of the anoxic zone 5 and connecting the anoxic zone 5 and the oxygenated zone 6. Specifically, the sludge circulation tank 5.1 is arranged along the length direction of the biochemical tank (perpendicular to the baffle passage of the anoxic zone 5), both ends of the sludge circulation tank 5.1 are respectively provided with a sludge circulation tank water inlet and a sludge circulation tank water outlet, the sludge circulation tank water inlet is located above the anoxic zone water outlet and is in communication with the start end of the oxygenated zone 6, the sludge circulation tank water outlet is in communication with the start end of the anoxic zone 5, the end of the oxygen depleted zone is connected with the sludge circulation tank through a sludge internal reflux pump 6.3, and the end of the oxygenated zone 6 is provided with an overflow weir and an outlet pipe 7 connected to the outside of the tank, which is used for discharging the wastewater treated by the anaerobic zone 4, the anoxic zone 5 and the oxygenated zone 6 into the subsequent structure. The anoxic zone 5 end water enters the sludge circulation tank 5.1 upward, a part of which flows into the oxygenated zone 6, and the other part is lifted by the sludge circulation pump in the sludge circulation tank 5.1 and then enters the start end of the anoxic zone 5 through the sludge circulation tank water outlet. The sludge circulation tank water outlet is arranged at the bottom of the sludge circulation tank 5.1, specifically, the water outlet is arranged at the bottom of the sludge circulation tank, and the water outlet is opposite to the start end of the anoxic zone 5, and the wastewater discharged by the sludge circulation tank directly enters the anoxic zone 5.

[0032] The working process of the double-layer biochemical tank is as follows: the raw water to be treated is partially (10%-30%) connected to the pre-anoxic zone 3 through the water inlet pipe 1 and partially (90%-70%) connected to the anaerobic zone 4, the external reflux sludge is connected to the pre-anoxic zone 3 through the sludge external reflux pipe 2, the pre-anoxic zone 3 water outlet flows into the anaerobic zone 4 through the hole arranged on the partition wall 2, the anaerobic zone 4 enters the anoxic zone 5 downward through the hole (i.e. the anaerobic zone water outlet 4.1) below the anaerobic zone, the anoxic zone 5 end water enters the start end of the sludge circulation tank 5.1 upward through the hole (i.e. the anoxic zone water outlet 5.4), the water of the anoxic zone 5 at the start end of the sludge circulation tank 5.1 is automatically entered into the sludge circulation tank 5.1 from the bottom of the anoxic zone 5 under the action of the water head), then part of the water flows into the oxygenated zone 6 through the water inlet hole, and the other part is lifted by the sludge circulation pump 5.2 and then enters the start end of the anoxic zone 5 downward through the sludge circulation tank water outlet (i.e. the anoxic zone water inlet hole 5.3), so as to realize the continuous circulation of the mixed liquid in the anoxic zone 5, the mixed liquid at the end of the oxygenated zone 6 enters the end of the sludge circulation tank 5.1 after passing through the oxygen depleted zone 6.1, and then enters the start end of the anoxic zone 5 downward through the sludge circulation tank water outlet (i.e. the anoxic zone water inlet hole 5.3) to complete the internal reflux of the mixed liquid, and the oxygenated zone 6 water outlet is discharged outside the tank through the water outlet pipe 7.

[0033] In the present application, by setting the pre-anoxic zone, the adverse effect of nitrate nitrogen carried by the external sludge reflux on biological phosphorus removal in the anaerobic zone can be reduced, and by setting the oxygen depletion zone, the dissolved oxygen concentration in the mixed liquor can be reduced to avoid excessive dissolved oxygen carried by the sludge internal reflux into the anoxic zone, thereby affecting the denitrification efficiency.

[0034] Specifically, in the above-mentioned double-layer biochemical tank, the pre-anoxic zone 3 and the anaerobic zone 4 are arranged at the side of the upper layer aerobic zone 6 and the oxygen depletion zone 6.1, the oxygen depletion zone 6.1 is located between the aerobic zone 6 and the first region, the sludge circulation tank 5.1 is located at the end of the aerobic zone 6 and the oxygen depletion zone 6.1, and corresponds to the beginning and end of the lower layer anoxic zone 5, and the sludge circulation tank 5.1 is arranged adjacent to the pre-anoxic zone 3.

[0035] It can be understood that, in order to ensure that the sludge discharged downward by the sludge circulation tank 5.1 directly enters the beginning of the anoxic zone 5, the lower layer of the biochemical tank is also provided with a partition wall five, which is used to ensure that the sludge circulation tank outlet is directly connected with the beginning of the anoxic zone 5 (i.e. to ensure that the sludge circulation tank outlet is directly located above the beginning of the anoxic zone 5).

[0036] Specifically, the partition wall five is located below the pre-anoxic zone 3, and the partition wall five is arranged along the width direction of the biochemical tank to form a flow guide channel with the edge of the biochemical tank, and the flow guide channel is in communication with the beginning of the anoxic zone 5.

[0037] Further, a partition wall four is arranged in the middle of the anaerobic zone 4 along the vertical water inlet direction, and the partition wall four is used to ensure that the sewage in the anaerobic zone 4 is deflected. It can be understood that, in order to facilitate water inlet of the water inlet pipe 1, the water inlet pipe 1 is arranged on the side wall of the two-layer anaerobic zone 4, the water inlet direction is perpendicular to the partition wall four and the water inlet end is not blocked by the partition wall four, so as to ensure that the untreated raw water entering the anaerobic zone 4 is deflected in the anaerobic zone 4 and then discharged from the anaerobic zone outlet 4.1 at the bottom.

[0038] Further, the aerobic zone 6 is in the form of multiple channels and is arranged in horizontal deflection. The oxygen depletion zone 6.1 is located at the end of the aerobic zone 6, and a submersible mixer is arranged in the middle of the oxygen depletion zone 6.1, and a sludge internal reflux pump 6.3 is arranged at the end, and the internal reflux sludge enters the beginning of the anoxic zone 5.

[0039] Further, each channel of the anoxic zone 5 is provided with a vent hole (also a manhole), which can be connected with a foul gas collection and blowing system, and the side of the vent hole can be provided with a residue discharge hole and a gate according to needs.

[0040] The double-layer biochemical pool adopts double-layer civil structure, and the anoxic zone adopts a series of multi-channel underground channels arranged horizontally in the lower layer of the biochemical pool to form a pipe culvert type anoxic reactor, which has good flow state of plug flow and complete mixing, and uniform flow rate, thereby avoiding the local sediment accumulation in the conventional single-layer biochemical pool, improving the volume utilization rate of the anoxic zone and the anoxic reaction efficiency. The water flow form of the anoxic zone is a head-tail circulation type, and a sludge circulating pump is used to realize the circulation flow of a large proportion of mixed liquid in the multi-channel anoxic zone, and the internal and external sludge return flows are superimposed to ensure that the flow rate in the channel is 0.3-0.5 m / s, and the channel is also provided with a vent hole (also a manhole) penetrating through the anaerobic zone or the aerobic zone to the top of the pool, which is convenient for connecting with the odor collection pipeline and collecting and treating the odor. The aerobic zone can adopt various flow state forms such as complete mixing and plug flow, and a sludge internal return pump is arranged at the end of the aerobic zone, and the return sludge enters the start end of the anoxic zone.

[0041] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A double layer biochemical tank characterized by, It comprises upper and lower layers, wherein the lower layer is anoxic zone, which is in the form of multi-channel dark ditch, horizontally baffling, the beginning of the anoxic zone is provided with an anoxic zone water inlet, and the end is provided with an anoxic zone water outlet; The upper layer is separated into a first region and a second region by a partition wall along the length direction of the biochemical pool, the first region is separated into a pre-anoxic zone and an anaerobic zone by a partition wall two along the width direction of the biochemical pool, and the water outlet of the anaerobic zone is correspondingly arranged with the water inlet of the anoxic zone; the second region is separated into an aerobic zone and an oxygen-consuming zone with one end communicating by a partition wall three along the length direction of the biochemical pool, and the second region is further provided with a sludge circulation tank; The sludge circulation tank is provided with a sludge circulation tank water inlet and a sludge circulation tank water outlet at both ends, the sludge circulation tank water inlet is located above the water outlet of the anoxic zone and communicates with the beginning of the aerobic zone, the sludge circulation tank water outlet communicates with the beginning of the anoxic zone, the end of the oxygen-consuming zone is connected with the sludge circulation tank through a sludge internal reflux pump, and the end of the aerobic zone is provided with an overflow weir and an outlet pipe connected to the outside of the pool; after the water outlet at the end of the anoxic zone enters the sludge circulation tank upward, a part of the water flows into the aerobic zone, and the other part of the water is lifted by a sludge circulation pump in the sludge circulation tank and then enters the beginning of the anoxic zone through the sludge circulation tank water outlet.

2. The dual layer biochemical tank according to claim 1, characterized in that, A partition wall four is arranged in the anaerobic zone along the vertical water inlet direction, and the partition wall four is used to ensure the water flow in the anaerobic zone.

3. The dual layer biochemical tank according to claim 1, characterized in that, The aerobic zone is in the form of multi-channel, horizontally baffling.

4. The dual layer biochemical tank of claim 1, wherein, The pre-anoxic zone and the anaerobic zone are arranged at the side of the second region of the upper layer, the oxygen-consuming zone is located between the aerobic zone and the first region, the sludge circulation tank is located at the end of the aerobic zone and the oxygen-consuming zone and corresponds to the beginning and the end of the anoxic zone of the lower layer, and the sludge circulation tank is arranged adjacent to the pre-anoxic zone.

5. The dual layer biochemical tank of claim 1, wherein, Holes are arranged on the partition wall two, the water outlet of the pre-anoxic zone flows into the anaerobic zone through the holes, and the water outlet of the anaerobic zone flows into the anoxic zone downward.

6. The double-layer biochemical pool according to any one of claims 1-5, characterized in that, The lower layer pool body is further provided with a partition wall five, and the partition wall five is used to ensure the connection between the sludge circulation tank water outlet and the beginning of the anoxic zone.

7. The dual layer biochemical tank according to claim 6, characterized in that, The partition wall five is located below the pre-anoxic zone, the partition wall five is arranged along the width direction of the biochemical pool and forms a flow guide channel with the edge of the biochemical pool, and the flow guide channel communicates with the beginning of the anoxic zone.

8. The dual layer biochemical tank of claim 1, wherein, The oxygen-consuming zone is provided with a submersible mixer.

9. The dual layer biochemical tank of claim 1, wherein, The anoxic zone is provided with a ventilation hole, the ventilation hole penetrates through the anaerobic zone or the aerobic zone to the top of the pool and is connected with a odor collection pipeline, and the ventilation hole also serves as a manhole.

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