Single-reflux integrated AOA sewage treatment device

Abstract

The utility model discloses a single-reflux integrated AOA sewage treatment device which comprises an anaerobic tank, a first selection tank, an aerobic tank, a second selection tank and an anoxic separation tank, aerators are arranged in the first selection tank, the second selection tank and the aerobic tank; a sludge-water double-separation device is arranged at the upper part of the anoxic separation tank; the system further comprises a sludge return system, the sludge return system comprises a return sludge pipe, a return sludge pump is mounted on the return sludge pipe, and sludge separated by the anoxic separation tank is conveyed back to the anaerobic tank. According to the utility model, the AOA process of ultimate nitrogen and phosphorus removal is adopted, the selection tank is arranged, so that the debugging operation has a space for later adjustment, the working procedures of the anoxic separation tank, the mud-water double-separation device and the like are combined together, the investment and land are saved, and the generation of bubbles with mud in effluent is avoided. And a single reflux technology is adopted, so that energy conservation is facilitated.

Description

A single-return integrated AOA wastewater treatment device Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to an integrated AOA wastewater treatment device with single-recirculation. Background Technology

[0002] AOA is an abbreviation for Anaerobic-Oxic-Anoxic, a process developed in recent years to overcome the shortcomings of the AAO process.

[0003] The AAO (Anaerobic-Anoxic-Oxic) process consists of an anaerobic tank, an anoxic tank, an aerobic tank, and a secondary sedimentation tank. The anaerobic tank releases phosphorus while simultaneously oxidizing some organic matter. The primary function of the anoxic tank is denitrification; nitrate nitrogen is supplied via internal circulation from the aerobic reactor. The aerobic tank removes organic matter, performs nitrification, and absorbs phosphorus. The secondary sedimentation tank separates sludge from water; a portion of the sludge is returned to the anaerobic tank, and the supernatant is discharged as treated wastewater. The inherent conflict between denitrification and phosphorus removal makes it difficult to achieve optimal results simultaneously; furthermore, a large amount of external carbon source must be added to the anoxic zone to enhance denitrification.

[0004] The AOA process consists of an anaerobic tank, an aerobic tank, an anoxic tank, and a secondary sedimentation tank. The main function of the anaerobic tank is to achieve sufficient intracellular carbon storage and phosphorus release by polyphosphate-accumulating organisms (PAOs). The main functions of the aerobic tank are nitrification and biological phosphorus removal, while the main function of the anoxic tank is denitrification. A key factor in the AOA process's high-efficiency nitrogen removal under low C / N ratio conditions is providing a favorable habitat for denitrifying polysaccharide-producing bacteria (DGAOs), making them the dominant species in the activated sludge. DGAOs can store organic matter as an intracellular carbon source when the organic matter concentration in the anaerobic tank is high, and then utilize these previously stored intracellular carbon sources, such as polyhydroxyalkanoates (PHAs) and glycogen, for endogenous denitrification in the subsequent anoxic zone where no external carbon source is available. Because the anoxic tank is located later, the nitrate nitrogen content in the returned sludge is extremely low, resulting in better phosphorus release by PAOs in the anaerobic tank and more efficient phosphorus absorption in the aerobic tank. Meanwhile, the post-anaerobic tank provides a living environment for denitrifying polyphosphate-accumulating bacteria (DPAOs), which enhances the denitrification and phosphorus removal process in the final stage of the biological treatment tank.

[0005] The AOA process enhances the internal carbon source denitrification process, thereby reducing carbon source consumption and saving operating costs, and currently has a very promising application prospect. However, some problems exist in its application: the reaction kinetic theory is not yet perfect, there are relatively few case studies, and there are no theoretical calculation formulas for engineering design parameters. Specifically, these problems manifest in the following ways: a long reaction time in the anaerobic tank helps the conversion of internal carbon sources, but too long a time wastes tank volume; some aerobic tanks have short reaction times, affecting ammonia nitrogen conversion; short anoxic time affects denitrification, while long time can lead to extreme denitrification and low nitrate concentration. Sludge is returned to the preceding anaerobic tank, which is beneficial for anaerobic phosphorus removal, but it also causes subsequent anaerobic phosphorus release in the secondary sedimentation tank, affecting the effluent phosphorus index; the retention time in the secondary sedimentation tank is quite long, and the sludge continues to denitrify, producing nitrogen gas that adheres to the sludge and is carried to the water surface, affecting the appearance and effluent quality. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this utility model provides an integrated AOA wastewater treatment device with single-recirculation.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0008] This utility model discloses an integrated AOA wastewater treatment device with single-recirculation, comprising an anaerobic tank, a first selection tank, an aerobic tank, a second selection tank, and an anoxic separation tank.

[0009] Aerators are installed in the first selection tank, the second selection tank, and the aerobic tank.

[0010] The first and second selection tanks are also equipped with mixers;

[0011] The first selection tank switches between aerobic and anaerobic functions, while the second selection tank switches between anoxic and aerobic functions.

[0012] The bottom of the anoxic separation tank is equipped with a suspension mixer, and the upper part is equipped with a mud-water dual separation device.

[0013] It also includes a sludge return system, which includes a sludge return pipe connected between the anoxic separation tank and the anaerobic tank. A sludge return pump is installed on the sludge return pipe to transport the sludge separated from the anoxic separation tank back to the anaerobic tank. One end of the sludge return system is also connected to a waste sludge pipe, which is equipped with a waste sludge pump for discharging waste sludge.

[0014] As a preferred technical solution of this utility model, an oxidation-reduction potentiometer is installed in the anaerobic tank.

[0015] As a preferred technical solution of this utility model, an anaerobic mixer is also installed in the anaerobic tank.

[0016] As a preferred technical solution of this utility model, the aerator is connected to an air duct, the input end of the air duct is connected to a blower, and an aeration control valve is installed on the connecting branch of the air duct to each aerator.

[0017] As a preferred technical solution of this utility model, one end of the air duct is connected to an inclined flushing pipe, and a flushing valve is connected between the inclined flushing pipe and the air duct. The flushing pipe is located in the mud-water dual separation device in the anoxic separation tank.

[0018] As a preferred technical solution of this utility model, an air volume flow meter is installed on the air duct.

[0019] As a preferred technical solution of this utility model, a return sludge flow meter is installed on the return sludge pipe, and a residual sludge flow meter is installed on the residual sludge pipe.

[0020] As a preferred technical solution of this utility model, it also includes an inlet pipe connected to the input end of the anaerobic tank and an outlet pipe connected to the output end of the anoxic separation tank, and an inlet flow meter is installed on the inlet pipe.

[0021] As a preferred technical solution of this utility model, both the aerobic tank and the anoxic separation tank are equipped with dissolved oxygen meters.

[0022] As a preferred technical solution of this utility model, sludge concentration meters are installed in both the anaerobic tank and the anoxic separation tank.

[0023] The beneficial effects of this utility model are:

[0024] This invention, through the establishment of a selection tank, allows for adjustments during commissioning and operation. Combining the anoxic separation tank and the sludge-water dual separation device into one process saves investment and land use, and reduces the generation of sludge carried by air bubbles in the effluent. The adoption of single-recirculation technology saves pump head, contributing to energy conservation. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 is a schematic diagram of the overall structure of this utility model. Detailed Implementation

[0027] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0028] Example: As shown in Figure 1, an integrated AOA wastewater treatment device with single-recirculation includes an anaerobic tank 1, a first selection tank 2, an aerobic tank 3, a second selection tank 4, and an anoxic separation tank 5.

[0029] It also includes an inlet pipe 11 connected to the input end of the anaerobic tank and an outlet pipe 12 connected to the output end of the anoxic separation tank 5. An inlet flow meter is installed on the inlet pipe 11.

[0030] Anaerobic tank 1 is equipped with a reduction potentiometer 22 and an anaerobic mixer 6. Both anaerobic tank 1 and anoxic separation tank 5 are equipped with sludge concentration meters 23 and 26. The anaerobic mixer 6 can be a submersible mixer (pump mixer).

[0031] Dissolved oxygen meters 24 and 25 are installed in both the aerobic tank 3 and the anoxic separation tank 5.

[0032] Aerators 8 are installed in the first selection tank 2, the second selection tank 4, and the aerobic tank 3. Aerators 8 are connected to air ducts 16, and blowers 15 are connected to the input end of air ducts 16. Aeration control valves 28, 29, and 30 are installed on the connecting branches of air ducts 16 and each aerator 8. Air volume flow meters 18 are installed on air ducts 16.

[0033] The first selection tank 2 and the second selection tank 4 are also equipped with a mixer 7;

[0034] It is worth mentioning that the mixer 7 can be equipped with a three-blade mixer.

[0035] The first selection tank 2 can be operated as an anaerobic tank with the aerator closed and the mixer 7 turned on, or as an aerobic tank with the aerator turned on and the mixer 7 turned off, with the mixer 7 blades positioned upwards to prevent damage to the aerator; the second selection tank 4 can be operated as an anoxic tank with the aerator 8 closed and the mixer 7 turned on, or as an aerobic tank with the aerator 8 turned on and the mixer 7 turned off, with the mixer 7 blades positioned upwards to prevent damage to the aerator 8.

[0036] The anoxic separation tank 5 is equipped with a suspension mixer or turbine mixer at the bottom and a sludge-water dual separation device at the top. One end of the air duct 16 is connected to an inclined flushing pipe 27, and a flushing valve 31 is connected between the inclined flushing pipe 27 and the air duct 16. The flushing pipe is located in the sludge-water dual separation device 10 within the anoxic separation tank 5. Sludge-water separation occurs at the top of the anoxic separation tank 5, and the sludge automatically slides to the bottom of the anoxic separation tank 5, maintaining the sludge concentration in the anoxic tank.

[0037] It also includes a sludge return system, which includes a sludge return pipe 32 connecting the anoxic separation tank 5 and the anaerobic tank 1. A sludge return pump 13 is installed on the sludge return pipe 32 to return the sludge separated from the anoxic separation tank 5 to the anaerobic tank 1. One end of the sludge return system is also connected to a waste sludge pipe 17, which is equipped with a waste sludge pump 14 for discharging waste sludge. A sludge return flow meter 20 is installed on the sludge return pipe 32, and a waste sludge flow meter 21 is installed on the waste sludge pipe 17.

[0038] The workflow of this embodiment is as follows:

[0039] The influent first enters anaerobic tank 1, where anaerobic mixer 6 mixes the influent, sludge returned from anoxic separation tank 5, and the mixed liquor within the tank, converting external carbon sources into internal carbon sources, and polyphosphate-accumulating bacteria release phosphorus. The wastewater then enters the aerobic tank, where nitrification occurs, converting ammonia nitrogen into nitrate nitrogen. Simultaneously, some organic matter is oxidized and decomposed under aerobic conditions. Next, it enters the anoxic tank, where denitrification occurs using the internal carbon sources stored in the anaerobic zone, reducing the nitrate nitrogen produced in aerobic tank 3 back to nitrogen gas, thus achieving denitrification. Because the anoxic zone utilizes the internal carbon sources stored in the anaerobic zone, the need for external carbon sources is reduced. Finally, after dual separation by a three-phase separator and inclined tube separator, the effluent is discharged through the effluent weir.

[0040] The sludge single return system returns the sludge from the anoxic separation tank 5 to the anaerobic tank 1, maintaining the sludge concentration in both the anaerobic tank 1 and the aerobic tank 3. Since the nitrate concentration of the returned sludge is low, it has little impact on the phosphorus-releasing bacteria.

[0041] The blower aeration inclined tube flushing system provides the oxygen needed for the aerobic tank and the amount of air needed for timed flushing of the inclined tubes.

[0042] When the sludge concentration in the anoxic separation tank 5 is detected to be too high, the residual sludge pump is turned on to discharge sludge, and the residual sludge pump is turned off when the appropriate concentration is reached.

[0043] After running for a period of time, if sludge clogs the inclined tubes, shut off the inlet water and backflow, stop the aeration, and start flushing the inclined tubes.

[0044] Application of the first selection tank 2: When the ammonia nitrogen and COD of the effluent are high, the aeration of the first selection tank 2 is started, its mixer is turned off, and it is operated as an aerobic tank; otherwise, it is operated as an anaerobic tank.

[0045] Application of the second selection tank 4: When the DO in the anoxic separation tank is high, the aeration of the second selection tank 4 is turned off, the mixer is turned on, and it is operated as an anoxic tank; when the total phosphorus in the effluent is high, or when the retention time in the anoxic separation tank is long and floating sludge appears, the aeration of the second selection tank 4 is turned on, its mixer is turned off, and it is operated as an aerobic tank.

[0046] The control system can automatically control according to construction and operation requirements, such as adjusting the fan frequency according to the influent flow meter and concentration to provide suitable dissolved oxygen; adjusting the flow rate of the return sludge pump according to the sludge concentration of the anoxic separation tank 5 and the anaerobic tank 1; and controlling the discharge of excess sludge according to the sludge concentration of the anoxic separation tank 5.

[0047] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A single-recirculation integrated AOA wastewater treatment device, characterized in that, It includes an anaerobic tank (1), a first selection tank (2), an aerobic tank (3), a second selection tank (4), and an anoxic separation tank (5); aerators (8) are installed in the first selection tank (2), the second selection tank (4), and the aerobic tank (3); a mixer (7) is also installed in the first selection tank (2) and the second selection tank (4); the first selection tank (2) switches between aerobic and anaerobic functions, and the second selection tank (4) switches between anoxic and aerobic functions; the bottom of the anoxic separation tank (5) is equipped with... The suspension mixer is equipped with a sludge-water separation device at the top; it also includes a sludge return system, which includes a return sludge pipe (32) connected between the anoxic separation tank (5) and the anaerobic tank (1), and a return sludge pump (13) installed on the return sludge pipe (32) to transport the sludge separated from the anoxic separation tank (5) back to the anaerobic tank (1). One end of the sludge return system is also connected to a residual sludge pipe (17), and a residual sludge pump (14) is installed on the residual sludge pipe (17) for discharging residual sludge.

2. The integrated AOA wastewater treatment device with single-recirculation as described in claim 1, characterized in that, An oxidation-reduction potentiometer (22) is installed in the anaerobic tank (1).

3. The integrated AOA wastewater treatment device with single-recirculation as described in claim 2, characterized in that, An anaerobic mixer (6) is also installed in the anaerobic tank (1).

4. The integrated AOA wastewater treatment device with single-recirculation as described in claim 1, characterized in that, The aerator (8) is connected to the air duct (16), the air duct (16) is connected to the blower (15) at the input end, and the air duct (16) is connected to each aerator (8) by an aeration control valve (28, 29, 30).

5. The integrated AOA wastewater treatment device with single-recirculation as described in claim 4, characterized in that, One end of the duct (16) is connected to an inclined flushing pipe (27), and a flushing valve (31) is connected between the inclined flushing pipe (27) and the duct (16). The flushing pipe is located in the mud-water dual separation device (10) in the anoxic separation tank (5).

6. The integrated AOA wastewater treatment device with single-recirculation as described in claim 5, characterized in that, An air flow meter (18) is installed on the air duct (16).

7. The integrated AOA wastewater treatment device with single-recirculation as described in claim 1, characterized in that, A return sludge flow meter (20) is installed on the return sludge pipe (32), and a residual sludge flow meter (21) is installed on the residual sludge pipe (17).

8. The integrated AOA wastewater treatment device with single-recirculation as described in claim 1, characterized in that, It also includes an inlet pipe (11) connected to the input end of the anaerobic tank and an outlet pipe (12) connected to the output end of the anoxic separation tank (5). An inlet flow meter is installed on the inlet pipe (11).

9. The integrated AOA wastewater treatment device with single-recirculation as described in claim 1, characterized in that, Dissolved oxygen meters (24, 25) are installed in both the aerobic tank (3) and the anoxic separation tank (5).

10. The integrated AOA wastewater treatment device with single-recirculation as described in claim 1, characterized in that, Sludge concentration meters (23, 26) are installed in both the anaerobic tank (1) and the anoxic separation tank (5).

Images