A sewage treatment system capable of flexibly switching between AOA and AOAO

Abstract

The present invention discloses a sewage treatment system capable of flexibly switching between AOA and AOAO, which relates to the technical field of sewage treatment. It includes an AOA sewage treatment tank group, and the AOA sewage treatment tank group comprises an anaerobic tank, an aerobic tank and an anoxic tank. It also includes an anaerobic tank reaction promotion mechanism and an impact-resistant secondary sedimentation tank mechanism. The anaerobic tank reaction promotion mechanism comprises a rotary drum. A plurality of brackets are equidistantly arranged at the top of the anaerobic tank. The middle parts of each bracket are respectively rotatably connected to a vertical rotary drum through bearings. The top parts of each rotary drum are respectively connected to a rotary power assembly. Three mounting sleeves are respectively arranged in an annular array on the outer peripheral side of the bottom of each rotary drum. This sewage treatment system capable of flexibly switching between AOA and AOAO can flexibly switch between two sewage treatment modes of AOA and AOAO according to the sludge sedimentation situation in the secondary sedimentation tank, can avoid the phenomenon of mud turning in the secondary sedimentation tank, and is conducive to reducing the energy consumption of sewage treatment and improving the sewage treatment efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and specifically to a sewage treatment system capable of flexibly switching between AOA and AOAO. Background Art

[0002] Currently, in order to solve the problems of low efficiency of simultaneous nitrogen and phosphorus removal, high operating energy consumption, and large carbon source addition in sewage treatment, the AOA sewage treatment system has become a research hotspot in the current sewage treatment field. The AOA sewage treatment system is composed of an anaerobic zone, an aerobic zone, an anoxic zone, and a sedimentation tank connected in series. Its process does not require nitrification liquid reflux and has a good nitrogen and phosphorus removal effect on urban domestic sewage with a low carbon-nitrogen ratio. Due to the low dissolved oxygen in the anoxic tank of the AOA sewage treatment system, the sludge entering the sedimentation tank forms nitrogen due to the denitrification reaction, resulting in the phenomenon of mud turning in the sedimentation tank. Therefore, the prior art has proposed the AOAO sewage treatment system, adding a post-aerobic zone between the anoxic zone and the sedimentation tank. The post-aerobic zone performs non-discriminatory aeration treatment on the sewage coming out of the anoxic zone, increasing the energy consumption and affecting the sewage treatment efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a sewage treatment system capable of flexibly switching between AOA and AOAO, which can flexibly switch between two sewage treatment modes of AOA and AOAO according to the sludge sedimentation situation in the secondary sedimentation tank, can avoid the phenomenon of mud turning in the secondary sedimentation tank, and at the same time is conducive to reducing the energy consumption of sewage treatment and improving the sewage treatment efficiency, and can effectively solve the problems in the background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A sewage treatment system capable of flexibly switching between AOA and AOAO, including an AOA sewage treatment tank group, the AOA sewage treatment tank group includes an anaerobic tank, an aerobic tank, and an anoxic tank, and the anaerobic tank, the aerobic tank, and the anoxic tank are sequentially connected in series through a water pumping component, and further includes:

[0005] An anaerobic tank reaction promotion mechanism, including a bracket, a rotating cylinder, a mounting sleeve, a water spraying radial pipe, a tangential nozzle, a rotating power component, and a nozzle pitching control component. A plurality of brackets are equidistantly arranged at the top of the anaerobic tank. The middle part of each bracket is respectively rotatably connected to a vertical rotating cylinder. The top of each rotating cylinder is respectively connected to a rotating power component. The bottom of the rotating cylinder extends into the anaerobic tank, and three mounting sleeves are respectively annularly arranged on the outer peripheral side of the bottom of each rotating cylinder. One end of each mounting sleeve is respectively rotatably connected to one end of a water spraying radial pipe. The other end of the water spraying radial pipe is provided with a tangential nozzle, and a nozzle pitching control component is connected to the side of the water spraying radial pipe;

[0006] An impact-resistant secondary sedimentation tank mechanism, the bottom of which is connected to the anaerobic tank and the anoxic tank through a sludge return mechanism, and the anoxic tank is connected to the impact-resistant secondary sedimentation tank mechanism through a water pumping component.

[0007] The anaerobic tank, aerobic tank and anoxic tank are connected in series through a water pumping component in sequence. Sewage enters the water spraying radial pipe through a rotating drum and a mounting sleeve, and then is sprayed into the anaerobic tank through a tangential nozzle. The sludge reflux mechanism refluxes the sludge precipitated in the impact-resistant secondary sedimentation tank mechanism into the anaerobic tank. The rotating power component drives the rotating drum to rotate relative to the bracket and the anaerobic tank. The rotating drum drives the water spraying radial pipe and the tangential nozzle to mix the sludge refluxed into the anaerobic tank with the sewage in the anaerobic tank. The denitrifying bacteria in the sludge use the organic matter in the sewage for denitrification, and part of the organic matter is converted into internal carbon source, and phosphate is released. The agitation of the water spraying radial pipe and the tangential nozzle on the sludge and sewage mixture is conducive to the anaerobic microorganisms to adsorb and absorb the organic matter in the sewage. The nozzle pitch control component can change the pitch angle of the tangential nozzle, and can continuously change the water spraying angle during the rotation of the tangential nozzle, which is conducive to further improving the stirring effect on the sludge and sewage mixture. Then, the sewage and sludge mixture in the anaerobic tank is sent to the aerobic tank through the water pumping component. The aeration device in the aerobic tank aerates the mud and water mixture. Aerobic phosphorus uptake reaction, nitrification reaction and simultaneous nitrification and denitrification reaction occur in the aerobic tank, generating nitrate while taking up phosphorus. Then, the mud and water mixture in the aerobic tank is sent to the anoxic tank through the water pumping component. The sludge reflux mechanism refluxes the sludge precipitated in the impact-resistant secondary sedimentation tank mechanism into the anoxic tank to complete the reflux of nitrate into the anoxic tank. Denitrification and nitrogen removal occur in the anoxic tank. Then, the mud and water mixture in the anoxic tank is sent to the impact-resistant secondary sedimentation tank mechanism through the water pumping component to precipitate the sludge in the mud and water mixture. If the sludge sedimentation performance deteriorates due to the formation of nitrogen gas caused by the denitrification reaction in the impact-resistant secondary sedimentation tank mechanism, the sewage is subjected to secondary aeration treatment when adding sewage to the impact-resistant secondary sedimentation tank mechanism to supply oxygen to the mud and water mixture, inhibit the denitrification reaction of the sewage in the sludge sedimentation chamber in the impact-resistant secondary sedimentation tank mechanism, reduce the generation of nitrogen gas, improve the sludge sedimentation performance, and avoid the situation of mud turning in the secondary sedimentation tank. If there is no mud turning situation in the impact-resistant secondary sedimentation tank mechanism during the operation of the sewage treatment system, no secondary aeration treatment is carried out, or the sewage treatment time required for aeration is reduced, while saving energy consumption.

[0008] Further, the nozzle pitch control component includes a follower frame, an electric telescopic rod, a synchronous ring, a push-pull rod and a convex rod. The rotating drum is fixedly sleeved with a follower frame at the position below the bracket. The bottom ends of both ends of the follower frame are respectively fixedly connected to the top ends of two electric telescopic rods. The bottom ends of the two electric telescopic rods are respectively fixedly connected to both sides of the synchronous ring. The bottom of the synchronous ring is movably connected to the top ends of three push-pull rods. A convex rod is respectively arranged on the side surface of each water spraying radial pipe. The bottom ends of the three push-pull rods are respectively movably connected to the ends of the corresponding convex rods.

[0009] The follower frame rotates with the rotating drum. When the electric telescopic rod extends, it can push the convex rod downward through the push rod. The convex rod drives the water spray radial pipe to rotate relative to the rotating drum through the mounting sleeve, enabling the tangent nozzle at the end of the water spray radial pipe to gradually lift upward. When the electric telescopic rod shortens, with the help of the push rod and the convex rod, the water spray radial pipe can rotate in the reverse direction, causing the tangent nozzle at the end of the water spray radial pipe to gradually move downward, thereby changing the pitch angle of the tangent nozzle and allowing the tangent nozzle to spray water into the anaerobic tank at different pitch angles. By spraying water, it promotes the flow of the sewage in the anaerobic tank and the full mixing of the sewage sludge in the anaerobic tank. Moreover, the change in the pitch angle of the tangent nozzle, combined with the rotation of the rotating drum and the water spray radial pipe, can also promote the agitation and mixing of the sewage sludge. Since power supply is required to control the telescopic movement of the electric telescopic rod, if a cable is directly electrically connected to the electric telescopic rod, the cable will be broken as the rotating drum rotates. Therefore, a conductive slip ring can be set at the top of the rotating drum, which is specifically used for transmitting power supply and signal power supply during unrestricted continuous rotation. With the help of the conductive slip ring, the electric telescopic rod can be powered and controlled while rotating.

[0010] Furthermore, the anaerobic tank reaction promotion mechanism further includes a circulating liquid pump. One end of an arched pipe is respectively connected to the top of each rotating drum through a rotary joint, and the other end of each arched pipe is respectively connected to the outlet of the circulating liquid pump. One end of a filling pipe is respectively connected to the inlet of each circulating liquid pump. A solenoid valve I is installed on the filling pipe. One end of a circulating suction pipe is also connected to the inlet of each circulating liquid pump, and the other end of the circulating suction pipe is connected to the anaerobic tank, and a solenoid valve II is installed on the circulating suction pipe. The filling pipe is connected to an external sewage source. When the solenoid valve II is closed and the solenoid valve I is opened, the circulating liquid pump operates to send the external sewage source into the rotating drum through the filling pipe, the arched pipe, and the rotary joint, and then into the anaerobic tank through the water spray radial pipe and the tangent nozzle. When the amount of sewage in the anaerobic tank is sufficient, the solenoid valve II is opened and the solenoid valve I is closed, and the circulating liquid pump continues to operate, which can complete the circulating mixing of the sewage in the anaerobic tank. The sewage in the anaerobic tank is pumped out and then re - sent into the anaerobic tank through the water spray radial pipe and the tangent nozzle. With the rotation of the water spray radial pipe and the tangent nozzle and the pitching movement of the tangent nozzle, the sewage in the anaerobic tank is fully mixed with the refluxed sludge, promoting the denitrifying bacteria in the sludge to utilize the organic matter in the sewage for denitrification, converting part of the organic matter into an internal carbon source and accelerating the release of phosphate. According to needs, a capping component can be added to the top of the anaerobic tank to seal the top of the anaerobic tank, and methane and other gases generated during the reaction can be collected at the top of the anaerobic tank.

[0011] Furthermore, the impact-resistant secondary sedimentation tank mechanism includes a circular tank body, a sludge collecting trough, a frustum-shaped tank bottom, and a peripheral water inlet and outlet assembly for the secondary sedimentation tank. The bottom of the circular tank body is provided with a frustum-shaped tank bottom, the center of the bottom of the frustum-shaped tank bottom is provided with a sludge collecting trough, and a peripheral water inlet and outlet assembly for the secondary sedimentation tank is installed inside the circular tank body. The circular tank body, the sludge collecting trough, and the frustum-shaped tank bottom constitute a basic secondary sedimentation tank structure. The peripheral water inlet and outlet assembly for the secondary sedimentation tank can allow the mud-water mixture to enter from the bottom of the periphery of the secondary sedimentation tank structure, and then allow the upper clear water to be discharged from the top of the periphery of the secondary sedimentation tank structure, which is beneficial to increasing the water inlet cross-section, making the water distribution more uniform, improving the volume utilization rate of the sedimentation tank, and also improving its surface load.

[0012] Furthermore, the peripheral water inlet and outlet assembly for the secondary sedimentation tank includes an inner tank body. A circular inner tank body is arranged inside the circular tank body. The inner side area of the inner tank body is a sludge sedimentation chamber. An annular chamber is formed between the circular tank body and the inner tank body. The bottom of the inner tank body is provided with peripheral water inlets in an annular array. An annular water outlet channel is arranged inside the inner tank body. One end of the clear water pipe is connected to the water outlet channel, and the other end of the clear water pipe extends to the outside of the circular tank body.

[0013] The mud-water mixture in the anoxic tank is sent to the annular chamber through the water pumping assembly. The mud-water mixture in the annular chamber enters the sludge sedimentation chamber through a plurality of peripheral water inlets. The peripheral water inlets serve as a water distribution structure, allowing the mud-water mixture to enter the bottom of the sludge sedimentation chamber more evenly and quickly diffuse in front of the sludge sedimentation chamber, and enter the upper clarification area from the bottom of the sludge sedimentation chamber at the lowest speed. Since the water inlet speed is very small, the short-circuit phenomenon accompanied by high-speed water inlet can be avoided, and the effective utilization coefficient of the tank volume is improved. Since the mud-water mixture rises slowly in a plane in the sludge sedimentation chamber, the activated sludge in the suspension layer flocculates and coagulates, making the activated sludge particles in the mixed liquid continuously collide, adsorb, flocculate, and combine with the activated sludge in the suspension layer, resulting in a good suspension clarification effect, improving the sludge sedimentation efficiency of the sedimentation tank. The clear water above the sludge sedimentation chamber crosses the inner edge of the top of the water outlet channel and enters the water outlet channel, and then is discharged through the clear water pipe.

[0014] Furthermore, the impact-resistant secondary sedimentation tank mechanism further includes an annular partition, a downcomer, and a downcomer control solenoid valve. An annular partition is provided between the outer side of the circular tank body and the outer side of the inner tank body. The annular partition divides the annular cavity into an upper impact-resistant aerobic zone and a lower dosing zone. Vertically arranged downcomers are annularly arrayed on the annular partition, and a downcomer control solenoid valve is installed in the middle of the downcomer. When the anaerobic tank sludge-water mixture is sent into the sludge sedimentation cavity, in order to quickly empty the anaerobic tank for the treatment of the next tank of sewage, the sludge-water mixture will quickly enter the sludge sedimentation cavity through the annular cavity and the peripheral water inlet. At this time, the load in the sludge sedimentation cavity exceeds the standard, and it will be greatly impacted. The sludge in the sludge sedimentation cavity is too late to settle. Therefore, the annular cavity is divided into an impact-resistant aerobic zone and a dosing zone by the annular partition. The sludge-water mixture first enters the impact-resistant aerobic zone for temporary storage, and then through the control of the downcomer and the downcomer control solenoid valve, the sludge-water mixture gradually enters the sludge sedimentation cavity through the dosing zone and the peripheral water inlet, slowing down the addition speed in the sludge sedimentation cavity. The impact-resistant aerobic zone plays a buffering role for water volume fluctuations. If mud turning occurs in the sludge sedimentation cavity, the sewage in the impact-resistant aerobic zone is aerated to inhibit the denitrification reaction of the sewage in the sludge sedimentation cavity and improve the sludge sedimentation performance. The impact-resistant aerobic zone plays a role of temporary storage and also serves as a post-aerobic zone, which can aerate the sludge-water mixture entering the sludge sedimentation cavity as needed, so as to realize the flexible switching between the AOA and AO AO treatment processes.

[0015] Furthermore, a flow-attenuating overflow mechanism is also included. The flow-attenuating overflow mechanism includes a weir, overflow retaining teeth, an annular mud guard, and an annular filter screen. A weir is provided on the inner peripheral side of the outlet channel. The inner and outer side edges of the top of the weir are respectively annularly arrayed with overflow retaining teeth. An annular mud guard is provided on the inner peripheral side of the weir. The outer side edge of the upper side of the annular mud guard is detachably installed with an annular filter screen. The annular mud guard guides the rising water flow. The clear water on the upper layer of the sludge sedimentation cavity crosses the upper side edge of the annular mud guard, then passes through the filtration of the annular filter screen, then crosses the overflow retaining teeth and enters the weir, and finally enters the outlet channel. The annular filter screen can filter the occasionally appearing scum, and the overflow retaining teeth are used for the uniform outflow of the water flow to avoid the too-fast rising flow rate of the local water flow causing the sludge to float up.

[0016] Further, it further includes a bottom sludge scraping mechanism. The bottom sludge scraping mechanism includes a gallery bridge, a sludge scraping motor, a sludge scraping rotating shaft, side rods, and a scraper. A gallery bridge is provided at the top of the circular tank body. A vertical sludge scraping rotating shaft is rotatably connected to the middle of the gallery bridge. The top of the sludge scraping rotating shaft is fixedly connected to the output shaft of the sludge scraping motor, and the sludge scraping motor is installed on the gallery bridge. The bottom of the sludge scraping rotating shaft is connected to two scrapers through two side rods. The gallery bridge is used to install the sludge scraping motor and the sludge scraping rotating shaft. The gallery bridge also facilitates the staff to walk above the circular tank body to observe the operation conditions inside the circular tank body and also facilitates the maintenance of the circular tank body. The sludge scraping motor drives the sludge scraping rotating shaft to rotate, and the sludge scraping rotating shaft drives the scraper to rotate through the side rods. The scraper is used to scrape the sludge attached to the upper side of the conical bottom of the tank, so that the sludge falls into the sludge collecting tank, which is convenient to be pumped away by the sludge pump, avoiding the anaerobic decay and deterioration of the sludge staying at the bottom of the tank for too long, and avoiding the gas generated by anaerobic digestion causing it to float in the form of lumps.

[0017] Further, it further includes a floating sludge collecting and cleaning mechanism. The floating sludge collecting and cleaning mechanism includes a collecting hopper. One end of a radial rod is fixedly connected to the sludge scraping rotating shaft through a fixed sleeve. Leakage holes are evenly formed in the collecting hopper. The collecting hopper is located above the annular mud baffle. A dismounting block is installed on the side surface of the collecting hopper, and the dismounting block is detachably connected to the other end of the radial rod. If floating sludge appears, the floating sludge will be filtered by the annular filter screen. The accumulation of floating sludge will affect the discharge efficiency of the clear water. Therefore, during the sludge scraping process, the sludge scraping rotating shaft drives the collecting hopper to rotate above the annular mud baffle through the fixed sleeve and the radial rod. The collecting hopper can collect the floating sludge filtered by the annular filter screen. A sinking opening can be arranged on the gallery bridge. When the collecting hopper rotates to below the sinking opening, the staff can take away the floating sludge in the collecting hopper through the sinking opening. The arrangement of the dismounting block facilitates the removal of the collecting hopper from the end of the radial rod.

[0018] Further, it also includes an aerobic zone aeration mechanism. The aerobic zone aeration mechanism includes an annular air pipe. An annular rail is fixedly connected to the inner peripheral side of the top of the circular pool body. A plurality of rollers are rotatably connected to the outer peripheral side of the annular air pipe in an annular array. The rollers are in rolling connection with the rail groove of the annular rail. The tops of a plurality of vertical pipes are fixedly connected to the bottom of the annular air pipe in an annular array. The bottom of each vertical pipe is fixedly connected with an aeration radial pipe. The aeration radial pipe is located at the bottom of the impact-resistant aerobic zone. Aeration heads are respectively arranged on both sides of the aeration radial pipe at equal distances. And the annular air pipe is connected to the air outlet of the air pump through a hose, and the annular air pipe is connected with an annular air pipe reciprocating movement assembly. The air pump pumps air into the annular air pipe through the hose. The gas in the annular air pipe enters the aeration radial pipe through the vertical pipe, and then is dispersed and discharged through the aeration heads, so as to aerate the mixed liquid in the impact-resistant aerobic zone, increase the oxygen content in the mixed liquid, and inhibit the denitrification reaction of microorganisms in the subsequent sludge sedimentation chamber. The annular air pipe reciprocating movement assembly is used to drive the annular air pipe to rotate reciprocally at a certain angle, so that the aeration radial pipe reciprocates in the annular impact-resistant aerobic zone, expanding the aeration range and the aeration uniformity.

[0019] Compared with the prior art, the beneficial effects of the sewage treatment system with flexible switching between AOA and AOAO are as follows:

[0020] 1. The rotation power assembly drives the rotating cylinder to rotate relative to the bracket and the anaerobic tank. The rotating cylinder drives the water spraying radial pipe and the tangential nozzle to mix the sludge flowing back into the anaerobic tank with the sewage in the anaerobic tank. The denitrifying bacteria in the sludge use the organic matter in the sewage for denitrification. Part of the organic matter is converted into internal carbon source, and phosphate is released. The agitation of the water spraying radial pipe and the tangential nozzle on the sludge and sewage mixture is conducive to the anaerobic microorganisms to adsorb and absorb the organic matter in the sewage. The nozzle pitch control assembly can change the pitch angle of the tangential nozzle, and can continuously change the water spraying angle during the rotation of the tangential nozzle, which is beneficial to further improving the stirring effect on the sludge and sewage mixture and promoting the biological reaction process in the anaerobic tank.

[0021] 2. If the sludge sedimentation performance deteriorates due to the denitrification reaction in the impact-resistant secondary sedimentation tank mechanism to form nitrogen, then when adding the mixed liquid into the impact-resistant secondary sedimentation tank mechanism, the mixed liquid is subjected to secondary aeration treatment to inhibit the denitrification reaction of microorganisms in the sludge sedimentation chamber in the impact-resistant secondary sedimentation tank mechanism, reduce the generation of nitrogen, and avoid the situation of sludge turning over in the secondary sedimentation tank. If there is no situation of sludge turning over in the impact-resistant secondary sedimentation tank mechanism during the operation of the sewage treatment system, then no secondary aeration treatment is carried out, or the sewage treatment time required for aeration is reduced, while saving energy consumption.

[0022] 3. The sludge-water mixture in the anoxic tank is sent to the annular cavity through the pump assembly. The sludge-water mixture in the annular cavity enters the sludge sedimentation cavity through multiple peripheral water inlets. The peripheral water inlets serve as a water distribution structure, enabling the sludge-water mixture to enter the bottom of the sludge sedimentation cavity more evenly and diffuse rapidly before entering the sludge sedimentation cavity, and entering the upper clarifying area from the bottom of the sludge sedimentation cavity at the lowest speed. Since the water inlet speed is very small, it can avoid the short-circuit phenomenon that usually occurs during high-speed water inlet, improving the effective utilization coefficient of the tank volume. Since the sludge-water mixture flows slowly upward in a plane in the sludge sedimentation cavity, the activated sludge in the suspension layer flocculates and aggregates, causing the activated sludge particles in the mixed liquid to continuously collide, adsorb, flocculate, and combine with the activated sludge in the suspension layer, resulting in a good suspension clarification effect and improving the sludge sedimentation efficiency of the sedimentation tank.

[0023] 4. The air pump pumps air into the annular air pipe through a hose. The gas in the annular air pipe enters the aeration radial pipe through the vertical pipe and then is dispersed and discharged through the aeration head to aerate the mixed liquid in the impact-resistant aerobic zone, increasing the oxygen content in the mixed liquid and inhibiting the denitrification reaction of the sewage in the subsequent sludge sedimentation cavity. The annular air pipe reciprocating assembly is used to drive the annular air pipe to rotate reciprocally at a certain angle, making the aeration radial pipe reciprocate in the annular impact-resistant aerobic zone, expanding the aeration range and the uniformity of aeration.

[0024] 5. It can flexibly switch between two sewage treatment modes, AOA and AOAO, according to the sludge sedimentation situation in the secondary sedimentation tank, avoid the phenomenon of mud turning in the secondary sedimentation tank, and at the same time help reduce the energy consumption of sewage treatment and improve the sewage treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the sewage treatment system with flexible switching between AOA and AOAO of the present invention;

[0026] Figure 2 For the present invention Figure 1 The partial enlarged structural diagram at A in it;

[0027] Figure 3 It is a schematic structural diagram of the anaerobic tank reaction promotion mechanism in the sewage treatment system with flexible switching between AOA and AOAO of the present invention;

[0028] Figure 4 It is a schematic rear structural diagram of the sewage treatment system with flexible switching between AOA and AOAO of the present invention;

[0029] Figure 5 It is a schematic partial structural diagram of the sewage treatment system with flexible switching between AOA and AOAO of the present invention;

[0030] Figure 6 For the present inventionFigure 5 Schematic diagram of the partial enlarged structure at B in the middle

[0031] Figure 7 Schematic diagram of the structure of the floating sludge collection and cleaning mechanism in the sewage treatment system with flexible switching between AOA and AOAO of the present invention

[0032] Figure 8 For the present invention Figure 5 Top view structure schematic diagram

[0033] Figure 9 For the present invention Figure 8 Schematic diagram of the cross-section at D in the middle of the present invention

[0034] Figure 10 For the present invention Figure 9 Schematic diagram of the partial enlarged structure at C in the middle of the present invention

[0035] In the figure: 1 AOA sewage treatment tank group, 11 anaerobic tank, 12 aerobic tank, 13 anoxic tank, 14 aeration device, 15 sewage agitation device, 16 water supply pipeline, 17 water pump, 2 anaerobic tank reaction promotion mechanism, 21 support, 22 rotating cylinder, 23 installation sleeve, 24 spray radial pipe, 25 tangential spray nozzle, 26 driven gear, 27 driving gear, 28 agitation motor, 29 rotary joint, 210 arched pipe, 211 circulating liquid pump, 212 filling pipe, 213 solenoid valve 1, 214 circulating suction pipe, 215 solenoid valve 2, 216 follower frame, 217 electric telescopic rod, 218 synchronous ring, 219 push-pull rod, 220 convex rod, 3 impact-resistant secondary sedimentation tank mechanism, 31 circular tank body, 32 sludge collection tank, 33 inner tank body, 34 peripheral water inlet, 35 water outlet channel, 36 clear water pipe, 37 annular partition board, 38 down pipe, 39 down pipe control solenoid valve, 310 sludge sedimentation cavity, 311 filling area, 312 impact-resistant aerobic area, 313 frustum-shaped pool bottom, 4 slow-flow overflow mechanism, 41 water outlet weir, 42 overflow retaining teeth, 43 annular mud guard, 44 annular filter screen, 5 pool bottom sludge scraping mechanism, 51 corridor bridge, 52 sludge scraping motor, 53 sludge scraping rotating shaft, 54 side rod, 55 scraper, 6 floating sludge collection and cleaning mechanism, 61 fixed sleeve, 62 radial rod, 63 disassembly block, 64 collection hopper, 7 aerobic area aeration mechanism, 71 annular rail, 72 roller, 73 annular air pipe, 74 vertical pipe, 75 aeration radial pipe, 76 aeration head, 77 hose, 78 air pump, 79 motor seat, 710 control motor, 711 support plate, 712 arc track, 713 sector slider, 714 connecting rod, 715 rotating rod, 8 sludge reflux mechanism, 81 sludge outlet pipe, 82 sludge pump, 83 sludge reflux pipe 1, 84 solenoid valve 3, 85 sludge reflux pipe 2, 86 solenoid valve 4, 87 sludge discharge pipe, 88 solenoid valve 5 Detailed implementation mode

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1. Please refer to Figures 1 to 10 , this embodiment provides a technical solution: a sewage treatment system capable of flexibly switching between AOA and AO / AO, including an AOA sewage treatment tank group 1. The AOA sewage treatment tank group 1 includes an anaerobic tank 11, an aerobic tank 12, and an anoxic tank 13. An aeration device 14 is arranged in the aerobic tank 12, and the aeration device 14 adopts a conventional aeration pipe. A sewage agitation device 15 is arranged in the anoxic tank 13, and the sewage agitation device 15 adopts a conventional agitation component. The anaerobic tank 11, the aerobic tank 12, and the anoxic tank 13 are connected in series through a water pumping component in sequence.

[0038] An anaerobic tank reaction promotion mechanism 2, an impact-resistant secondary sedimentation tank mechanism 3, and a sludge return mechanism 8 are also provided.

[0039] The anaerobic tank reaction promotion mechanism 2 includes a support 21, a rotating cylinder 22, a mounting sleeve 23, a water spraying radial pipe 24, a tangential nozzle 25, a rotational power component, and a nozzle pitch control component. A plurality of supports 21 are arranged at equal intervals on the top of the anaerobic tank 11. The number of supports 21 can be selected according to the length of the anaerobic tank 11. In this embodiment, three supports are adopted. In order to reduce the agitation dead angle, the inner sides of both ends of the anaerobic tank 11 can be set to be arc-shaped. The middle parts of each support 21 are respectively rotatably connected to a vertical rotating cylinder 22 through bearings. The top of each rotating cylinder 22 is respectively connected to a rotational power component. The bottom of the rotating cylinder 22 extends into the anaerobic tank 11, and three mounting sleeves 23 are respectively arranged in a circular array on the outer peripheral side of the bottom of each rotating cylinder 22. One end of a water spraying radial pipe 24 is rotatably connected to each mounting sleeve 23, and a tangential nozzle 25 is arranged at the other end of the water spraying radial pipe 24, and a nozzle pitch control component is connected to the side of the water spraying radial pipe 24.

[0040] The rotational power component includes a driven gear 26, a driving gear 27, and an agitation motor 28. A driven gear 26 is fixedly sleeved on the top of each rotating cylinder 22. An agitation motor 28 is installed on the support 21. The output shaft of the agitation motor 28 is fixedly connected to a driving gear 27. The driving gear 27 is meshed with the driven gear 26. When the agitation motor 28 works, the rotation of the rotating cylinder 22 can be driven through the transmission of the driven gear 26 and the driving gear 27, so as to provide power for the rotation of the rotating cylinder 22.

[0041] The nozzle pitch control assembly includes a follower frame 216, an electric telescopic rod 217, a synchronous ring 218, a push-pull rod 219, and a convex rod 220. The rotary drum 22 is fixedly sleeved with the follower frame 216 at a position below the support 21. The bottom ends of both sides of the follower frame 216 are respectively fixedly connected to the top ends of two electric telescopic rods 217. The bottom ends of the two electric telescopic rods 217 are respectively fixedly connected to both sides of the synchronous ring 218. The bottom of the synchronous ring 218 is movably connected to the top ends of three push-pull rods 219 through a pin shaft. Each side of each water spray radial pipe 24 is respectively provided with a convex rod 220. The bottom ends of the three push-pull rods 219 are respectively movably connected to the corresponding ends of the convex rods 220 through a pin shaft.

[0042] The follower frame 216 rotates with the rotary drum 22. When the electric telescopic rod 217 extends, it can push the convex rod 220 downward through the push-pull rod 219. The convex rod 220 drives the water spray radial pipe 24 to rotate relative to the rotary drum 22 through the mounting sleeve 23, enabling the tangent nozzle 25 at the end of the water spray radial pipe 24 to gradually lift upward. When the electric telescopic rod 217 shortens, with the help of the push-pull rod 219 and the convex rod 220, the water spray radial pipe 24 can be rotated in the reverse direction, enabling the tangent nozzle 25 at the end of the water spray radial pipe 24 to gradually move downward, thereby changing the pitch angle of the tangent nozzle 25, allowing the tangent nozzle 25 to spray water into the anaerobic tank 11 at different pitch angles, promoting the flow of the sewage in the anaerobic tank 11 by means of spraying water, and promoting the full mixing of the sewage sludge in the anaerobic tank 11. Moreover, the change in the pitch angle of the tangent nozzle 25 in cooperation with the rotation of the rotary drum 22 and the water spray radial pipe 24 can also promote the agitation and mixing of the sewage sludge. Since power supply is required to control the telescopic movement of the electric telescopic rod 217, if a cable is directly connected to the electric telescopic rod 217, the cable will be broken as the rotary drum 22 rotates. Therefore, a conductive slip ring can be provided at the top of the rotary drum 22, which is specifically used for transmitting power supply and signal power during unrestricted continuous rotation. With the help of the conductive slip ring, the electric telescopic rod 217 can be powered and controlled while rotating.

[0043] The anaerobic pond reaction promotion mechanism 2 further includes a rotary joint 29, an arched pipe 210, a circulating liquid pump 211, a filling pipe 212, a solenoid valve 1 213, a circulating suction pipe 214, and a solenoid valve 2 215. The top of each rotary drum 22 is respectively connected to one end of the arched pipe 210 through the rotary joint 29. The other end of each arched pipe 210 is respectively connected to the outlet of the circulating liquid pump 211. The inlet of each circulating liquid pump 211 is respectively connected to one end of the filling pipe 212. The solenoid valve 1 213 is installed on the filling pipe 212. The inlet of each circulating liquid pump 211 is also connected to one end of the circulating suction pipe 214. The other end of the circulating suction pipe 214 is connected to the anaerobic pond 11, and the solenoid valve 2 215 is installed on the circulating suction pipe 214. The filling pipe 212 is connected to an external sewage source. Close the solenoid valve 2 215, open the solenoid valve 1 213, and the circulating liquid pump 211 works to send the external sewage source into the rotary drum 22 through the filling pipe 212, the arched pipe 210, and the rotary joint 29, and then send it into the anaerobic pond 11 through the water spraying radial pipe 24 and the tangential nozzle 25. When the amount of sewage in the anaerobic pond 11 is sufficient, open the solenoid valve 2 215, close the solenoid valve 1 213, and the circulating liquid pump 211 continues to work to complete the circulating mixing of the sewage in the anaerobic pond 11. The sewage in the anaerobic pond 11 is pumped out and then sent back into the anaerobic pond 11 through the water spraying radial pipe 24 and the tangential nozzle 25 again. With the rotation of the water spraying radial pipe 24 and the pitching movement of the tangential nozzle 25, the sewage in the anaerobic pond 11 is fully mixed with the refluxed sludge, promoting the denitrifying bacteria in the sludge to convert the organic matter in the sewage into an internal carbon source and accelerating the release of phosphate. According to needs, a capping component can be added to the top of the anaerobic pond 11 to seal the top of the anaerobic pond 11, and gases such as methane generated during the reaction can be collected at the top of the anaerobic pond 11.

[0044] The bottom of the impact-resistant secondary sedimentation pond mechanism 3 is connected to the anaerobic pond 11 and the anoxic pond 13 through the sludge reflux mechanism 8, and the anoxic pond 13 is connected to the impact-resistant secondary sedimentation pond mechanism 3 through the water pumping assembly.

[0045] The impact-resistant secondary sedimentation pond mechanism 3 includes a circular pond body 31, a sludge collection tank 32, a frustum-shaped pond bottom 313, and a secondary sedimentation pond peripheral water inlet and outlet assembly. The frustum-shaped pond bottom 313 is arranged at the bottom of the circular pond body 31. The sludge collection tank 32 is arranged at the center of the bottom of the frustum-shaped pond bottom 313. The secondary sedimentation pond peripheral water inlet and outlet assembly is installed inside the circular pond body 31. The circular pond body 31, the sludge collection tank 32, and the frustum-shaped pond bottom 313 form a basic secondary sedimentation pond structure. The secondary sedimentation pond peripheral water inlet and outlet assembly can allow sewage to enter from the peripheral bottom of the secondary sedimentation pond structure, and then allow the upper clear water to be discharged from the peripheral top of the secondary sedimentation pond structure, which is beneficial to increasing the water inlet section, making the water distribution more uniform, improving the volume utilization rate of the sedimentation tank, and also improving its surface load.

[0046] The inlet and outlet components around the secondary sedimentation tank include an inner tank body 33, a peripheral water inlet 34, a water outlet channel 35, a clear water pipe 36, and a sludge sedimentation chamber 310. A circular inner tank body 33 is arranged inside the circular tank body 31. The inner area of the inner tank body 33 is the sludge sedimentation chamber 310. The area between the circular tank body 31 and the inner tank body 33 is an annular chamber. The peripheral water inlets 34 are arranged in an annular array at the bottom of the inner tank body 33. An annular water outlet channel 35 is arranged inside the inner tank body 33. The tops of the circular tank body 31 and the inner tank body 33 are flush. The horizontal position of the top of the water outlet channel 35 is lower than the top of the inner tank body 33. One end of the clear water pipe 36 is connected to the water outlet channel 35, and the other end of the clear water pipe 36 extends to the outside of the circular tank body 31.

[0047] The water pumping component includes a water delivery pipe 16 and a water pump 17. The water pump 17 serves as the power source for pumping water. The muddy water mixture in the anaerobic tank 11 can be sent into the aerobic tank 12 with the help of the water delivery pipe 16 and the water pump 17. The muddy water mixture in the aerobic tank 12 can be sent into the anoxic tank 13 with the help of the water delivery pipe 16 and the water pump 17. The muddy water mixture in the anoxic tank 13 can be sent to the top of the annular chamber with the help of the water delivery pipe 16 and the water pump 17.

[0048] The muddy water mixture in the anoxic tank 13 is sent to the annular chamber through the water pumping component. The muddy water mixture in the annular chamber enters the sludge sedimentation chamber 310 through multiple peripheral water inlets 34. The peripheral water inlets 34 serve as a water distribution structure, allowing the muddy water mixture to enter the bottom of the sludge sedimentation chamber 310 more evenly and quickly diffuse before entering the sludge sedimentation chamber 310, and enter the upper clarification area from the bottom of the sludge sedimentation chamber 310 at the lowest speed. Due to the very small water inlet speed, the short-circuit phenomenon usually accompanied by high-speed water inlet can be avoided, and the effective utilization coefficient of the tank volume is improved. Since the muddy water mixture slowly rises in a plane in the sludge sedimentation chamber 310, the activated sludge in the suspension layer flocculates and aggregates, causing the activated sludge particles in the sewage mixture to continuously collide, adsorb, flocculate, and combine with the activated sludge in the suspension layer, resulting in a good suspension clarification effect and improving the sludge sedimentation efficiency of the sedimentation tank. The clear water in the upper layer of the sludge sedimentation chamber 310 crosses the inner edge of the top of the water outlet channel 35 and enters the water outlet channel 35, and then is discharged through the clear water pipe 36.

[0049] The impact-resistant secondary sedimentation tank mechanism 3 further includes an annular partition 37, a downcomer 38, a downcomer control solenoid valve 39, a filling area 311, and an impact-resistant aerobic area 312. An annular partition 37 is provided between the outer side of the circular tank body 31 and the outer side of the inner tank body 33. The annular partition 37 divides the annular cavity into the upper impact-resistant aerobic area 312 and the lower filling area 311. Vertically arranged downcomers 38 are annularly arrayed on the annular partition 37, and a downcomer control solenoid valve 39 is installed in the middle of the downcomer 38. When the muddy water mixture in the anoxic tank 13 is sent into the sludge sedimentation chamber 310, in order to quickly empty the anoxic tank 13 for the treatment of the next tank of sewage, the muddy water mixture will quickly enter the sludge sedimentation chamber 310 through the annular cavity and the peripheral water inlet 34. At this time, the load in the sludge sedimentation chamber 310 exceeds the standard and will be subjected to a greater impact, and the sludge in the sludge sedimentation chamber 310 has no time to settle. Therefore, the annular cavity is divided into an impact-resistant aerobic area 312 and a filling area 311 by the annular partition 37. The sewage sludge mixture first enters the impact-resistant aerobic area 312 for temporary storage, and then the mixture is gradually allowed to enter the sludge sedimentation chamber 310 through the filling area 311 and the peripheral water inlet 34 by controlling the downcomer 38 and the downcomer control solenoid valve 39, slowing down the speed of adding to the sludge sedimentation chamber 310. The impact-resistant aerobic area 312 plays a buffering role for a large amount of sewage. If mud turning occurs in the sludge sedimentation chamber 310, the mixture in the impact-resistant aerobic area 312 is aerated to inhibit the denitrification reaction of the sewage in the sludge sedimentation chamber 310 and improve the sludge sedimentation performance. The impact-resistant aerobic area 312 plays a role in temporarily storing the muddy water mixture and also serves as a post-aerobic area, and can aerate the mixture entering the sludge sedimentation chamber 310 as needed, so as to realize the flexible switching between the AOA and AOAO treatment processes.

[0050] The impact-resistant aerobic area 312 is integrated with the sedimentation tank, without occupying additional space to build a post-aerobic area separately. It can quickly realize aerobic treatment operations when needed, and when not needed, the impact-resistant aerobic area 312 only serves as a temporary storage area for mixing, slowing down the speed of sending the mixture into the sludge sedimentation chamber 310 and improving the impact resistance of the sedimentation tank.

[0051] In order to enable the aeration process to be carried out in the impact-resistant aerobic zone 312, an aerobic zone aeration mechanism 7 is also provided. The aerobic zone aeration mechanism 7 includes an annular rail 71, rollers 72, an annular air pipe 73, vertical pipes 74, aeration radial pipes 75, aeration heads 76, a hose 77, an air pump 78, and an annular air pipe reciprocating movement assembly. An annular rail 71 is fixedly connected to the inner peripheral side of the top of the circular pool body 31. A plurality of rollers 72 are rotatably connected to the outer peripheral side of the annular air pipe 73 in an annular array. In order to maintain the stability of the annular air pipe 73 during rotation, the number of rollers 72 is not less than six. The rollers 72 are in rolling connection with the rail groove of the annular rail 71. The bottoms of a plurality of vertical pipes 74 are fixedly connected to the top of the annular air pipe 73 in an annular array. The number of vertical pipes 74 is not less than twelve. The bottom of each vertical pipe 74 is fixedly connected to an aeration radial pipe 75 respectively. The aeration radial pipes 75 are distributed along the radial direction of the annular rail 71. The aeration radial pipes 75 are located at the bottom inside the impact-resistant aerobic zone 312. Aeration heads 76 are respectively arranged at equal distances on both sides of the aeration radial pipe 75. And the annular air pipe 73 is connected to the air outlet of the air pump 78 through a hose 77. The air pump 78 is installed outside the circular pool body 31. And the annular air pipe 73 is connected to an annular air pipe reciprocating movement assembly.

[0052] The annular air pipe reciprocating movement assembly includes a motor base 79, a control motor 710, a support plate 711, an arc track 712, a sector slider 713, a connecting rod 714, and a rotating rod 715. An arc track 712 is fixedly connected to the top of the circular pool body 31. The center of the circle where the arc track 712 is located coincides with the center of the circular pool body 31. A sector slider 713 is slidably connected in the arc track 712. The bottom of the sector slider 713 is fixedly connected to the top of the annular air pipe 73. The top of the sector slider 713 is movably connected to one end of the connecting rod 714 through a movable shaft one. The other end of the connecting rod 714 is movably connected to one end of the rotating rod 715 through a movable shaft two. The other end of the rotating rod 715 is fixedly connected to the output shaft at the top of the control motor 710. A support plate 711 is fixedly connected to the end of the arc track 712. The support plate 711 is rotatably connected to the output shaft at the top of the control motor 710. The bottom of the control motor 710 is installed on the outer peripheral side of the top of the circular pool body 31 through the motor base 79. When the control motor 710 works, it drives the rotating rod 715 to rotate. The rotating rod 715 can drive the sector slider 713 to reciprocate in the arc track 712 through the connecting rod 714. Since the center of the circle where the arc track 712 is located coincides with the center of the circular pool body 31, the annular air pipe 73 can be driven to rotate back and forth at a certain angle.

[0053] The air pump 78 pumps air into the annular air pipe 73 through the hose 77. The gas in the annular air pipe 73 enters the aeration radial pipe 75 through the vertical pipe 74, and then is dispersed and discharged through the aeration head 76 to aerate the mixed liquid in the impact-resistant aerobic zone 312, increasing the oxygen content in the mixed liquid and inhibiting the denitrification reaction of the sludge in the subsequent sludge sedimentation chamber. The annular air pipe positive and negative reciprocating movement assembly is used to drive the annular air pipe 73 to rotate forward and backward at a certain angle, enabling the aeration radial pipe 75 to reciprocate in the annular impact-resistant aerobic zone 312, expanding the aeration range and the uniformity of aeration.

[0054] The sludge reflux mechanism 8 includes a sludge discharge pipe 81, a sludge pump 82, a first sludge reflux pipe 83, a solenoid valve three 84, a second sludge reflux pipe 85, a solenoid valve four 86, a sludge drainage pipe 87, and a solenoid valve five 88. One end of the sludge discharge pipe 81 is connected to the side of the sludge collection tank 32, and the other end of the sludge discharge pipe 81 is connected to the inlet of the sludge pump 82. The outlet of the sludge pump 82 is respectively connected to one end of the sludge drainage pipe 87 and the first sludge reflux pipe 83. A solenoid valve five 88 is installed on the sludge drainage pipe 87. The other end of the first sludge reflux pipe 83 is connected to the anaerobic tank 11, and a solenoid valve three 84 is installed at the end of the first sludge reflux pipe 83 close to the anaerobic tank 11. The middle of the first sludge reflux pipe 83 is connected to one end of the second sludge reflux pipe 85, and the other end of the second sludge reflux pipe 85 is connected to the anoxic tank 13. A solenoid valve four 86 is installed on the second sludge reflux pipe 85. The sludge pump 82 can discharge the sludge in the sludge collection tank 32 through the sludge discharge pipe 81. By closing the solenoid valve three 84 and the second sludge reflux pipe 85 and opening the solenoid valve five 88, the sludge can be discharged for subsequent operations such as pressure filtration. By closing the second sludge reflux pipe 85 and the solenoid valve five 88 and opening the solenoid valve three 84, the sludge can be refluxed into the anaerobic tank 11 through the first sludge reflux pipe 83. By closing the solenoid valve three 84 and the solenoid valve five 88 and opening the second sludge reflux pipe 85, the sludge can be refluxed into the anoxic tank 13 through the second sludge reflux pipe 85.

[0055] In use, sewage enters the water spray radial pipe 24 through the rotary drum 22 and the mounting sleeve 23, and then is sprayed into the anaerobic tank 11 through the tangential nozzle 25. The sludge reflux mechanism 8 returns the sludge precipitated in the shock-resistant secondary sedimentation tank mechanism 3 to the anaerobic tank 11. The rotary power assembly drives the rotary drum 22 to rotate relative to the support 21 and the anaerobic tank 11. The rotary drum 22 drives the water spray radial pipe 24 and the tangential nozzle 25 to mix the sludge returned to the anaerobic tank 11 with the sewage in the anaerobic tank 11. The denitrifying bacteria in the sludge utilize the organic matter in the sewage for denitrification. Part of the organic matter is converted into internal carbon source, and phosphate is released. The agitation of the water spray radial pipe 24 and the tangential nozzle 25 on the sludge and sewage mixture is conducive to the anaerobic microorganisms to adsorb and absorb the organic matter in the sewage. The nozzle pitch control assembly can change the pitch angle of the tangential nozzle 25, and can continuously change the water spray angle during the rotation of the tangential nozzle 25, which is conducive to further improving the stirring effect on the sludge and sewage mixture. Then, the mud-water mixture in the anaerobic tank 11 is sent to the aerobic tank 12 through the water pumping assembly. The aeration device 14 in the aerobic tank 12 aerates the mud-water mixture. Aerobic phosphorus uptake reaction, nitrification reaction and simultaneous nitrification and denitrification reaction occur in the aerobic tank 12, generating nitrate and taking up phosphorus at the same time. Then, the mud-water mixture in the aerobic tank 12 is sent to the anoxic tank 13 through the water pumping assembly. The sludge reflux mechanism 8 returns the sludge precipitated in the shock-resistant secondary sedimentation tank mechanism 3 to the anoxic tank 13 to complete the reflux of nitrate into the anoxic tank 13. Denitrification and nitrogen removal occur in the anoxic tank 13. Then, the mud-water mixture in the anoxic tank 13 is sent to the shock-resistant secondary sedimentation tank mechanism 3 through the water pumping assembly to precipitate the sludge in the mud-water mixture. If the sludge sedimentation performance deteriorates due to the formation of nitrogen gas caused by the denitrification reaction in the shock-resistant secondary sedimentation tank mechanism 3, the sewage is subjected to secondary aeration treatment when adding sewage to the shock-resistant secondary sedimentation tank mechanism 3 to inhibit the denitrification reaction of the mud-water mixture in the sludge sedimentation chamber in the shock-resistant secondary sedimentation tank mechanism 3, reduce the generation of nitrogen gas, and avoid the situation of mud turning in the secondary sedimentation tank. If there is no mud turning in the shock-resistant secondary sedimentation tank mechanism 3 during the operation of the sewage treatment system, no secondary aeration treatment is carried out, or the sewage treatment time required for aeration is reduced, while saving energy consumption.

[0056] Embodiment 2. Please refer to Figures 1 to 10 , this embodiment provides a technical solution: a sewage treatment system that can flexibly switch between AOA and AO / AO. This embodiment is substantially the same as that of Embodiment 1, and the difference lies in:

[0057] In order to slow down the discharge speed of the clear water and filter the possible floating sludge discharged, a slow-flow overflow mechanism 4 is also provided. The slow-flow overflow mechanism 4 includes a water outlet weir 41, overflow retaining teeth 42, an annular sludge baffle 43 and an annular filter screen 44. The water outlet weir 41 is arranged on the inner peripheral side of the water outlet channel 35. The inner and outer side edges of the top of the water outlet weir 41 are respectively provided with overflow retaining teeth 42 in an annular array. The annular sludge baffle 43 is arranged on the inner peripheral side of the water outlet weir 41. The cross section of the annular sludge baffle 43 is an arc structure. The outer side edge of the upper side of the annular sludge baffle 43 is detachably installed with an annular filter screen 44. The outer side of the annular filter screen 44 is closely attached to the inner peripheral side of the water outlet weir 41, and the horizontal position of the top of the annular filter screen 44 is higher than the top of the overflow retaining teeth 42. The annular sludge baffle 43 guides the rising water flow. The clear water in the upper layer of the sludge sedimentation chamber 310 crosses the upper side edge of the annular sludge baffle 43, then passes through the filtration of the annular filter screen 44, then crosses the overflow retaining teeth 42 and enters the water outlet weir 41, and finally enters the water outlet channel 35. Among them, the annular filter screen 44 can filter the occasionally appearing floating scum, and the overflow retaining teeth 42 are used for the uniform outflow of the water flow, preventing the too fast rising flow of part of the water from causing the sludge to float up.

[0058] Due to the provision of the water outlet weir 41, the overflow retaining teeth 42, the annular sludge baffle 43 and the annular filter screen 44, the sewage treatment system can easily handle the phenomenon of sludge turning over in a short time. After the sludge turning over phenomenon occurs, the aerobic zone aeration mechanism 7 is put into work, with good working flexibility and high redundancy, avoiding excessive sludge impurities in the subsequent clear water and reducing the pressure on the subsequent sewage treatment equipment.

[0059] Embodiment 3, please refer to Figures 1 to 10 , this embodiment provides a technical solution: a sewage treatment system capable of flexibly switching between AOA and AOAO. This embodiment is generally the same as that of Embodiment 2, and the difference lies in:

[0060] In order to handle the sludge at the top and bottom in the secondary sedimentation tank, a bottom sludge scraping mechanism 5 and a floating sludge collecting and cleaning mechanism 6 are respectively arranged. Among them, the bottom sludge scraping mechanism 5 includes a gallery bridge 51, a sludge scraping motor 52, a sludge scraping rotating shaft 53, side rods 54 and a scraper 55. A gallery bridge 51 is arranged at the top of the circular pool body 31. The middle part of the gallery bridge 51 is rotatably connected with a vertical sludge scraping rotating shaft 53 through a bearing. The top of the sludge scraping rotating shaft 53 is fixedly connected to the output shaft of the sludge scraping motor 52. The sludge scraping motor 52 is installed on the gallery bridge 51. The bottom of the sludge scraping rotating shaft 53 is connected to two scrapers 55 through two side rods 54. The two scrapers 55 respectively cooperate with the upper side of the conical bottom 313 of the pool. The gallery bridge 51 is used to install the sludge scraping motor 52 and the sludge scraping rotating shaft 53. The gallery bridge 51 also facilitates the staff to walk above the circular pool body 31 to observe the operation conditions in the circular pool body 31 and also facilitates the maintenance of the circular pool body 31. The sludge scraping motor 52 drives the sludge scraping rotating shaft 53 to rotate. The sludge scraping rotating shaft 53 drives the scraper 55 to rotate through the side rod 54. The scraper 55 is used to scrape the sludge attached to the upper side of the conical bottom 313, so that the sludge falls into the sludge collecting tank 32, which is convenient to be drained away by the sludge pump, avoiding the anaerobic decay and deterioration of the sludge staying at the bottom of the pool for too long, and avoiding the gas generated by anaerobic respiration from reducing its density and causing it to float in the form of lumps.

[0061] It also includes a floating sludge collecting and cleaning mechanism 6. The floating sludge collecting and cleaning mechanism 6 includes a fixed sleeve 61, a radial rod 62, a disassembly block 63 and a collecting hopper 64. One end of the radial rod 62 is fixedly connected to the sludge scraping rotating shaft 53 through the fixed sleeve 61. Leakage holes are evenly arranged on the collecting hopper 64. And the collecting hopper 64 is located above the annular mud guard 43. And a disassembly block 63 is installed on the side surface of the collecting hopper 64. The disassembly block 63 is detachably connected to the other end of the radial rod 62. If there is suspended sludge, the suspended sludge will be filtered by the annular filter screen 44. The accumulation of the suspended sludge will affect the drainage efficiency of the clear water. Therefore, during the sludge scraping process, the sludge scraping rotating shaft 53 drives the collecting hopper 64 to rotate above the annular mud guard 43 through the fixed sleeve 61 and the radial rod 62. The collecting hopper 64 can collect the floating sludge filtered by the annular filter screen 44. A sinking opening can be arranged on the gallery bridge 51. When the collecting hopper 64 rotates to below the sinking opening, the staff can take away the floating sludge in the collecting hopper 64 through the sinking opening. The setting of the disassembly block 63 facilitates the removal of the collecting hopper 64 from the end of the radial rod 62.

[0062] It should be noted that the aeration device 14, the sewage stirring device 15, the stirring motor 28, the electric telescopic rod 217, the solenoid valve one 213, the solenoid valve two 215, the circulating liquid pump 211, the water pump 17, the sewage discharge control solenoid valve 39, the air pump 78, the control motor 710, the sludge pump 82, the solenoid valve three 84, the solenoid valve four 86, the solenoid valve five 88 and the sludge scraping motor 52 disclosed in the above embodiments are all controlled by an external PLC controller to work. The control method adopts the method commonly used in the prior art. Among them, the sludge scraping motor 52 adopts a servo motor.

[0063] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0064] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sewage treatment system capable of flexibly switching between AOA and AOAO, comprising an AOA sewage treatment pond group (1), wherein the AOA sewage treatment pond group (1) includes an anaerobic pond (11), an aerobic pond (12) and an anoxic pond (13), and the anaerobic pond (11), the aerobic pond (12) and the anoxic pond (13) are connected in series through a water pumping component in sequence, and is characterized in that, It also includes: An anaerobic pond reaction promotion mechanism (2), which includes a rotary drum (22), a water spraying radial pipe (24), a tangential nozzle (25) and a nozzle pitching control component. A plurality of brackets (21) are equidistantly arranged at the top of the anaerobic pond (11). The middle part of each bracket (21) is rotatably connected to a vertical rotary drum (22). The top of each rotary drum (22) is respectively connected to a rotary power component. The bottom of the rotary drum (22) extends into the anaerobic pond (11). Three mounting sleeves (23) are annularly arranged on the outer peripheral side of the bottom of each rotary drum (22). One end of a water spraying radial pipe (24) is rotatably connected to each mounting sleeve (23). The other end of the water spraying radial pipe (24) is provided with a tangential nozzle (25). And a nozzle pitching control component is connected to the side of the water spraying radial pipe (24); The nozzle pitching control component includes a follower frame (216), an electric telescopic rod (217), a synchronous ring (218), a push-pull rod (219) and a convex rod (220). A follower frame (216) is fixedly sleeved at the position of the rotary drum (22) below the bracket (21). The bottom ends of both ends of the follower frame (216) are respectively fixedly connected to the tops of two electric telescopic rods (217). The bottom ends of the two electric telescopic rods (217) are respectively fixedly connected to both sides of the synchronous ring (218). The bottom of the synchronous ring (218) is movably connected to the tops of three push-pull rods (219). A convex rod (220) is respectively arranged on the side of each water spraying radial pipe (24). The bottom ends of the three push-pull rods (219) are respectively movably connected to the ends of the corresponding convex rods (220); An impact-resistant secondary sedimentation tank mechanism (3), the bottom of which is connected to the anaerobic pond (11) and the anoxic pond (13) through a sludge return mechanism (8), and the anoxic pond (13) is connected to the impact-resistant secondary sedimentation tank mechanism (3) through a water pumping component; The impact-resistant secondary sedimentation tank mechanism (3) includes a circular pond body (31), a sludge collection tank (32), a frustum-shaped pond bottom (313) and a secondary sedimentation tank peripheral water inlet and outlet component. A frustum-shaped pond bottom (313) is arranged at the bottom of the circular pond body (31). A sludge collection tank (32) is arranged at the center of the bottom of the frustum-shaped pond bottom (313). A secondary sedimentation tank peripheral water inlet and outlet component is installed inside the circular pond body (31); The secondary sedimentation tank peripheral water inlet and outlet component includes an inner pond body (33). A circular inner pond body (33) is arranged inside the circular pond body (31). The inner area of the inner pond body (33) is a sludge sedimentation cavity (310). An annular cavity is formed between the circular pond body (31) and the inner pond body (33). And peripheral water inlets (34) are annularly arranged at the bottom of the inner pond body (33). An annular water outlet channel (35) is arranged inside the inner pond body (33). One end of a clear water pipe (36) is connected to the water outlet channel (35). The other end of the clear water pipe (36) extends to the outside of the circular pond body (31); The impact-resistant secondary sedimentation tank mechanism (3) further includes an annular partition plate (37), a drain pipe (38), and a drain control solenoid valve (39). An annular partition plate (37) is arranged between the outer side of the circular tank body (31) and the outer side of the inner tank body (33). The annular partition plate (37) divides the annular cavity into an upper impact-resistant aerobic zone (312) and a lower injection zone (311). Vertically arranged drain pipes (38) are annularly arrayed on the annular partition plate (37), and a drain control solenoid valve (39) is installed in the middle of the drain pipe (38). It further includes an aerobic zone aeration mechanism (7). The aerobic zone aeration mechanism (7) includes an annular air pipe (73). An annular rail (71) is fixedly connected to the inner peripheral side of the top of the circular tank body (31). A plurality of rollers (72) are rotatably connected to the outer peripheral side of the annular air pipe (73) in an annular array. The rollers (72) are in rolling connection with the rail groove of the annular rail (71). The bottoms of a plurality of vertical pipes (74) are fixedly connected to the top of the annular air pipe (73) in an annular array. The bottom of each vertical pipe (74) is fixedly connected to an aeration radial pipe (75). Aeration heads (76) are respectively arranged at equal distances on both sides of the aeration radial pipe (75). The annular air pipe (73) is connected to the air outlet of an air pump (78) through a hose (77), and the annular air pipe (73) is connected to an annular air pipe forward and reverse reciprocating movement assembly. It further includes a flow retardation and overflow mechanism (4). The flow retardation and overflow mechanism (4) includes a weir (41), overflow retaining teeth (42), an annular mud guard (43), and an annular filter screen (44). A weir (41) is arranged on the inner peripheral side of the water outlet channel (35). Overflow retaining teeth (42) are annularly arrayed on the inner and outer side edges of the top of the weir (41). An annular mud guard (43) is arranged on the inner peripheral side of the weir (41). An annular filter screen (44) is detachably installed on the outer side edge of the upper side of the annular mud guard (43).

2. The sewage treatment system with flexible switching between AOA and AOAO according to claim 1, characterized in that: The anaerobic tank reaction promotion mechanism (2) further includes a circulating liquid pump (211). The top of each rotating cylinder (22) is respectively connected to one end of an arched pipe (210) through a rotary joint (29). The other end of each arched pipe (210) is respectively connected to the outlet of the circulating liquid pump (211). The inlet of each circulating liquid pump (211) is respectively connected to one end of a filling pipe (212). A solenoid valve I (213) is installed on the filling pipe (212). The inlet of each circulating liquid pump (211) is also connected to one end of a circulating suction pipe (214). The other end of the circulating suction pipe (214) is connected to the anaerobic tank (11), and a solenoid valve II (215) is installed on the circulating suction pipe (214).

3. The sewage treatment system with flexible switching between AOA and AOAO according to claim 1, characterized in that: It further includes a bottom sludge scraping mechanism (5), and the bottom sludge scraping mechanism (5) includes a gallery bridge (51), a sludge scraping motor (52), a sludge scraping rotating shaft (53), side rods (54) and a scraper (55). A gallery bridge (51) is provided at the top of the circular pool body (31). A vertical sludge scraping rotating shaft (53) is rotatably connected to the middle of the gallery bridge (51). The top of the sludge scraping rotating shaft (53) is fixedly connected to the output shaft of the sludge scraping motor (52), and the sludge scraping motor (52) is installed on the gallery bridge (51). The bottom of the sludge scraping rotating shaft (53) is connected to two scrapers (55) through two side rods (54).

4. The sewage treatment system with flexible switching between AOA and AOAO according to claim 3, characterized in that: It further includes a floating sludge collecting and cleaning mechanism (6), and the floating sludge collecting and cleaning mechanism (6) includes a collecting hopper (64). One end of a spoke rod (62) is fixedly connected to the sludge scraping rotating shaft (53) through a fixing sleeve (61). The collecting hopper (64) is evenly provided with water leakage holes, and the collecting hopper (64) is located above the annular mud guard (43). A disassembly block (63) is installed on the side of the collecting hopper (64), and the disassembly block (63) is detachably connected to the other end of the spoke rod (62).

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