Alternating continuous flow aerobic granular sludge culture system

Abstract

The invention provides an alternate continuous flow aerobic granular sludge culture system which comprises a first alternate tank, a second alternate tank and a facultative tank, the first alternate tank and the second alternate tank are alternately used as a sedimentation tank and a reaction tank, a secondary sedimentation tank is not needed, and the utilization rate of a structure is increased. The first water distribution pipe and the second water distribution pipe distribute inlet water to the bottom to make preferential contact with sludge, and a high-load banquet environment is created. The sludge in the first alternation pool and the second alternation pool is alternately in a feast state and a starvation state, so that the formation of granular sludge is promoted. The first alternating tank and the second alternating tank are intermittently in anaerobic, aerobic and anoxic states, and the facultative tank is intermittently in aerobic and anoxic states, so that pollutants in sewage can be removed without arranging a reflux device, and the damage of power equipment to a granular sludge structure is avoided. The first alternating tank and the second alternating tank alternately feed water, and the facultative tank alternately aerates and stirs, so that anaerobic, aerobic and anoxic alternate operation is realized, and the nitrogen and phosphorus removal performance can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and more specifically, relates to an alternating continuous flow aerobic granular sludge cultivation system. Background Art

[0002] Aerobic granular sludge is a granular microbial aggregate formed by self-agglomeration of microorganisms under special conditions. It has advantages that are difficult to match with ordinary activated sludge methods: simultaneous nitrogen and phosphorus removal, compact structure, good sludge settling performance, high biomass, strong impact resistance, etc. Aerobic granular sludge technology is considered to be a low-carbon and high-efficiency innovative technology in the sewage treatment industry due to its significant engineering advantages such as small land area, low energy consumption, and high efficiency. It meets the current technical needs of my country in the field of sewage treatment, can meet the requirements of sewage treatment industry for raising standards and reducing consumption, and help solve water pollution problems. It is one of the sewage treatment technologies with the greatest development potential.

[0003] Aerobic granular sludge technology has been widely used in intermittent flow sewage treatment processes. Intermittent flow aerobic granular sludge processes of different scales have been applied in engineering at home and abroad. In the continuous flow sewage treatment process, due to the use of plug flow water inlet, the substrate concentration gradient is small and the pollutant mass transfer power is small, which is not conducive to the cultivation and stable maintenance of aerobic granular sludge. In order to achieve the functions of nitrogen removal and phosphorus removal, it is necessary to set up anaerobic, anoxic and aerobic zones in different areas; at the same time, a secondary sedimentation tank is set up to separate the mixed liquid from mud and water; therefore, the traditional activated sludge process has many structures and the utilization rate of the structures is low. The nitrification liquid return system and the sludge return system will also destroy the structure of the sludge and affect the stability of the granular sludge. Summary of the invention

[0004] The purpose of the present invention is to provide an alternating continuous flow aerobic granular sludge cultivation system to solve the problems of poor settling performance, small particle size, easy breakage, poor nitrogen and phosphorus removal performance and low structure utilization of the existing continuous flow activated sludge.

[0005] In order to achieve the above objectives, in a first aspect, the present invention provides an alternating continuous flow aerobic granular sludge cultivation system, comprising:

[0006] a first alternating pool, wherein the first alternating pool is provided with a first water distribution unit, a first supernatant collection unit and a first aeration unit, wherein the first water distribution unit is provided at the top of the first alternating pool, a plurality of first water distribution pipes are connected below the first water distribution unit, and the first water distribution pipes extend to the bottom of the first alternating pool, the first water distribution unit is further provided with a first raw water inlet and a first mixed liquid inlet, the first supernatant collection unit is provided with a first supernatant outlet, and the first alternating pool is further provided with a first mud discharge port and a first mixed liquid outlet;

[0007] a second alternating pool, wherein a second water distribution unit, a second supernatant collection unit and a second aeration unit are provided in the second alternating pool, a plurality of second water distribution pipes are connected below the second water distribution unit, the second water distribution pipes extend to the bottom of the second alternating pool, the second water distribution unit is further provided with a second raw water inlet and a second mixed liquid inlet, the second supernatant collection unit is provided with a second supernatant outlet, and the second alternating pool is further provided with a second mud discharge outlet and a second mixed liquid outlet;

[0008] The anoxic tank is provided with an agitator, a third aeration unit, a third raw water inlet, a third mixed liquor outlet, a fourth mixed liquor outlet, a third mixed liquor inlet and a fourth mixed liquor inlet, wherein the third mixed liquor outlet is connected to the first mixed liquor inlet through a first mixed liquor valve, the fourth mixed liquor outlet is connected to the second mixed liquor inlet through a second mixed liquor valve, the third mixed liquor inlet is connected to the first mixed liquor outlet through a third mixed liquor valve, and the fourth mixed liquor inlet is connected to the second mixed liquor outlet through a fourth mixed liquor valve.

[0009] Optionally, the first water distribution unit and the second water distribution unit are both water distribution weirs.

[0010] Optionally, the first supernatant collection unit and the second supernatant collection unit are both air weirs;

[0011] The first supernatant collection unit is further provided with a first air inlet and a first air outlet, the first air inlet is provided with a first air inlet valve, and the first air outlet is provided with a first air outlet valve;

[0012] The second supernatant collection unit is provided with a second air inlet and a second air outlet, the second air inlet is provided with a second air inlet valve, and the second air outlet is provided with a second air outlet valve.

[0013] Optionally, the alternating continuous flow aerobic granular sludge cultivation system further comprises:

[0014] An air compressor is connected to the first intake valve and the second intake valve.

[0015] Optionally, the first supernatant liquid outlet is provided with a first supernatant liquid outlet valve;

[0016] The first mud discharge port is provided with a first mud discharge valve;

[0017] The second supernatant liquid outlet is provided with a second supernatant liquid outlet valve;

[0018] The second mud discharge port is provided with a second mud discharge valve.

[0019] Optionally, the alternating continuous flow aerobic granular sludge cultivation system further comprises:

[0020] A raw water tank, wherein a water pump is provided in the raw water tank, wherein the water pump is connected to the first raw water inlet, the second raw water inlet and the third raw water inlet through a water supply pipeline, wherein the first raw water inlet is provided with a first raw water inlet valve, the second raw water inlet is provided with a second raw water inlet valve, and the third raw water inlet is provided with a third raw water inlet valve.

[0021] Optionally, the first aeration unit, the second aeration unit and the third aeration unit are all aeration disks, the first aeration unit is provided with a first aeration inlet, the second aeration unit is provided with a second aeration inlet, and the third aeration unit is provided with a third aeration inlet.

[0022] Optionally, the alternating continuous flow aerobic granular sludge cultivation system further comprises:

[0023] A blower is connected to the first aeration inlet, the second aeration inlet and the third aeration inlet, the first aeration inlet is provided with a first aeration valve, the second aeration inlet is provided with a second aeration valve, and the third aeration inlet is provided with a third aeration valve.

[0024] Optionally, the first aeration unit is disposed at the bottom of the first alternating tank;

[0025] The second aeration unit is disposed at the bottom of the second alternating tank;

[0026] The third aeration unit is arranged at the bottom of the aerobic tank.

[0027] Optionally, the alternating continuous flow aerobic granular sludge cultivation system also includes a control unit, which is electrically connected to the first mixed liquor valve, the second mixed liquor valve, the third mixed liquor valve, the fourth mixed liquor valve, the first air inlet valve, the first exhaust valve, the second air inlet valve, the second exhaust valve, the air compressor, the first supernatant outlet valve, the first sludge discharge valve, the second supernatant outlet valve, the second sludge discharge valve, the water pump, the first raw water inlet valve, the second raw water inlet valve, the third raw water inlet valve, the blower, the first aeration valve, the second aeration valve, the third aeration valve and the agitator.

[0028] In a second aspect, the present invention provides an alternating continuous flow aerobic granular sludge cultivation method, using the alternating continuous flow aerobic granular sludge cultivation system described in the first aspect, comprising the following steps:

[0029] Step 1: Introduce sewage into the first alternating tank and distribute it to the bottom, introduce sewage at the top of the first alternating tank into the anoxic tank, introduce the mixed liquid of the anoxic tank into the second alternating tank, discharge the supernatant of the second alternating tank out of the system, and continue to operate for a first set time;

[0030] Step 2: aerating the first alternating tank and introducing the mud-water mixture into the anoxic tank, and introducing the mixture in the anoxic tank into the second alternating tank, and continuing the operation for a second set time;

[0031] Step 3: the first alternating tank stops taking in water and continues aeration, the sewage is introduced into the anoxic tank and stirred, the mixed liquid in the anoxic tank is introduced into the second alternating tank, and the operation is continued for a third set time;

[0032] Step 4: the first alternating tank stops aeration and discharges the remaining sludge after precipitation, the anoxic tank stops stirring and performs aeration, and the sludge-water mixture in the anoxic tank is introduced into the second alternating tank, and the operation continues for a fourth set time;

[0033] Step 5: introducing sewage into the second alternating tank and distributing it to the bottom, stopping water intake into the anoxic tank and continuing aeration, introducing the mixed liquid of the anoxic tank into the first alternating tank, discharging the supernatant of the first alternating tank from the system, and continuing the operation for a fifth set time;

[0034] Step 6: The second alternating tank is aerated and the mud-water mixture is introduced into the anoxic tank, and the mixed liquid of the anoxic tank is introduced into the first alternating tank, and the operation is continued for a sixth set time;

[0035] Step 7: the second alternating tank stops taking in water and continues aeration, the sewage is introduced into the anoxic tank and stirred, the mixed liquid in the anoxic tank is introduced into the first alternating tank, and the operation continues for the seventh set time;

[0036] Step 8: the second alternating tank stops aeration and discharges the remaining sludge after precipitation, the anoxic tank stops stirring and starts aeration, and the mud-water mixture in the anoxic tank is introduced into the first alternating tank, and the operation continues for an eighth set time;

[0037] Step 9: Repeat steps 1 to 8 in a loop.

[0038] The beneficial effects of the present invention are: providing an alternating continuous flow aerobic granular sludge cultivation system, including a first alternating pool, a second alternating pool and an anoxic pool, the first alternating pool and the second alternating pool can alternately serve as a sedimentation pool and a reaction pool, there is no need to set up a second sedimentation pool separately, and the utilization rate of the structure is improved. The first water distribution pipe and the second water distribution pipe can distribute raw water to the bottom of the first alternating pool and the second alternating pool, and the incoming water and the sludge are preferentially contacted to create a high-load feast environment. The sludge in the first alternating pool and the second alternating pool is alternately in a feast and starvation state, forming a feast-starvation alternating environment in time and space, which is conducive to the secretion of EPS and promotes the formation of granular sludge. The first alternating pool and the second alternating pool are intermittently in an anaerobic, aerobic and anoxic state, and the anoxic pool is intermittently in an aerobic and anoxic state. There is no need to set up a sludge return and a nitrification liquid return system, so that pollutants such as carbon, nitrogen, and phosphorus in sewage can be removed, power equipment can be reduced, energy consumption can be reduced, and the damage to the granular sludge structure by power equipment such as a reflux pump can be avoided. The first alternating pool and the second alternating pool are alternately inflowed with water, and the anoxic pool is alternately aerated and stirred to achieve alternating operation of anaerobic, aerobic and anoxic, which can improve the performance of nitrogen and phosphorus removal.

[0039] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0041] Figure 1 A schematic structural diagram of an alternating continuous flow aerobic granular sludge cultivation system according to an embodiment of the present invention is shown.

[0042] Figure 2 A flow chart of an alternating continuous flow aerobic granular sludge cultivation method according to an embodiment of the present invention is shown.

[0043] Figure 3 The diagram shows the sludge particle size distribution of the biological pool when the alternating continuous flow aerobic granular sludge cultivation system according to one embodiment of the present invention is in stable operation.

[0044] Description of reference numerals:

[0045] 1. First alternating tank; 11. First water distribution unit; 111. First raw water inlet; 112. First raw water inlet valve; 113. First mixed liquid inlet; 114. First water distribution pipe; 12. First supernatant liquid collecting unit; 121. First supernatant liquid outlet; 122. First supernatant liquid outlet valve; 13. First aeration unit; 131. First aeration inlet; 132. First aeration valve; 141. First mud outlet; 142. First mud outlet valve; 143. First mixed liquid outlet; 144. First air inlet; 145. First air inlet valve; 146. First exhaust outlet; 147. First exhaust valve;

[0046] 2. Second alternating pool; 21. Second water distribution unit; 211. Second raw water inlet; 212. Second raw water inlet valve; 213. Second mixed liquid inlet; 214. Second water distribution pipe; 22. Second supernatant liquid collecting unit; 221. Second supernatant liquid outlet; 222. Second supernatant liquid outlet valve; 23. Second aeration unit; 231. Second aeration inlet; 232. Second aeration valve; 241. Second mud discharge outlet; 242. Second mud discharge valve; 243. Second mixed liquid outlet; 244. Second air inlet; 245. Second air inlet valve; 246. Second exhaust outlet; 247. Second exhaust valve;

[0047] 3. Oxygenation tank; 31. Third aeration unit; 311. Third aeration inlet; 322. Third aeration valve; 32. Agitator; 331. Third raw water inlet; 332. Third raw water inlet valve; 333. Third mixed liquid outlet; 334. First mixed liquid valve; 335. Fourth mixed liquid outlet; 336. Second mixed liquid valve; 337. Third mixed liquid inlet; 338. Third mixed liquid valve; 339. Fourth mixed liquid inlet; 340. Fourth mixed liquid valve;

[0048] 4. Raw water tank; 41. Water pump; 42. Water supply pipeline;

[0049] 5. Air compressor;

[0050] 6. Blower;

[0051] 7. Control unit. DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0053] like Figure 1As shown, this embodiment provides an alternating continuous flow aerobic granular sludge cultivation system, comprising:

[0054] A first alternating pool 1, wherein the first alternating pool 1 is provided with a first water distribution unit 11, a first supernatant collection unit 12 and a first aeration unit 13, wherein the first water distribution unit 11 is provided at the top of the first alternating pool 1, and a plurality of first water distribution pipes 114 are connected below the first water distribution unit 11, wherein the first water distribution pipes 114 extend to the bottom of the first alternating pool 1, and the first water distribution unit 11 is further provided with a first raw water inlet 111 and a first mixed liquid inlet 113, the first supernatant collection unit 12 is provided with a first supernatant outlet 121, and the first alternating pool 1 is further provided with a first mud discharge port 141 and a first mixed liquid outlet 143;

[0055] A second alternating pool 2, wherein the second alternating pool 2 is provided with a second water distribution unit 21, a second supernatant collection unit 22, and a second aeration unit 23, wherein the second water distribution unit 21 is connected to a plurality of second water distribution pipes 214 below, wherein the second water distribution pipes 214 extend to the bottom of the second alternating pool 2, wherein the second water distribution unit 21 is further provided with a second raw water inlet 211 and a second mixed liquid inlet 213, wherein the second supernatant collection unit 22 is provided with a second supernatant outlet 221, and the second alternating pool 2 is further provided with a second mud discharge port 241 and a second mixed liquid outlet 243;

[0056] The facultative aeration tank 3 is provided with a third aeration unit 31, a third raw water inlet 331, a third mixed liquor outlet 333, a fourth mixed liquor outlet 335, a third mixed liquor inlet 337 and a fourth mixed liquor inlet 339. The third mixed liquor outlet 333 is connected to the first mixed liquor inlet 113 through a first mixed liquor valve 334, the fourth mixed liquor outlet 335 is connected to the second mixed liquor inlet 213 through a second mixed liquor valve 336, the third mixed liquor inlet 337 is connected to the first mixed liquor outlet 143 through a third mixed liquor valve 338, and the fourth mixed liquor inlet 339 is connected to the second mixed liquor outlet 243 through a fourth mixed liquor valve 340.

[0057] In specific implementation, as shown in Table 1, the aerobic granular sludge cultivation using this system is divided into eight process cycles.

[0058] Table 1

[0059]

[0060]

[0061] The specific working process of the system is as follows:

[0062] Process 1:

[0063] The first raw water inlet 111 is opened, the second raw water inlet 211 is closed, the third raw water inlet 331 is closed, the first supernatant liquid outlet 121 is closed, the second supernatant liquid outlet 221 is opened, the first aeration unit 13 is not working, the second aeration unit 23 is not working, the third aeration unit 31 is working, the first mixed liquid valve 334 is closed, the second mixed liquid valve 336 is opened, the third mixed liquid valve 338 is opened, the fourth mixed liquid valve 340 is closed, the agitator 32 is closed, the first mud discharge port 141 is closed, and the second mud discharge port 241 is closed.

[0064] The raw water enters the bottom of the first alternating pool 1 through the first water distribution unit 11 and contacts with the sludge. The sludge at the bottom of the first alternating pool 1 is in a high-load feast environment, and denitrification reaction and phosphorus release by polyphosphate bacteria occur during this process. The supernatant in the first alternating pool 1 enters the anoxic pool 3 through the first mixed liquor outlet 143 and the third mixed liquor inlet 337. The third aeration unit 31 puts the anoxic pool 3 in an aerated state and COD oxidation, nitrification reaction and phosphorus absorption occur. The mixed liquor in the anoxic pool 3 enters the second alternating pool 2 through the fourth mixed liquor outlet 335 and the second mixed liquor inlet 213. The mixed liquor is separated from the mud and water by gravity sedimentation in the second alternating pool 2. The supernatant in the second alternating pool 2 is collected by the second supernatant collection unit 22 and discharged from the system by the second supernatant outlet 221. The sludge in the second alternating pool 2 is in a hungry state. In this embodiment, the duration of this process is 60 minutes.

[0065] Process 2:

[0066] The first raw water inlet 111 is opened, the second raw water inlet 211 is closed, the third raw water inlet 331 is closed, the first supernatant liquid outlet 121 is closed, the second supernatant liquid outlet 221 is opened, the first aeration unit 13 is working, the second aeration unit 23 is not working, the third aeration unit 31 is working, the first mixed liquid valve 334 is closed, the second mixed liquid valve 336 is opened, the third mixed liquid valve 338 is opened, the fourth mixed liquid valve 340 is closed, the agitator 32 is closed, the first mud discharge port 141 is closed, and the second mud discharge port 241 is closed.

[0067] The first alternating pool 1 starts to be aerated, and COD oxidation, nitrification reaction and phosphorus absorption occur; the mud-water mixture in the first alternating pool 1 continues to enter the anoxic pool 3 through the first mixed liquor outlet 143 and the third mixed liquor inlet 337 to replenish the sludge concentration in the anoxic pool 3, and the anoxic pool 3 is in an aerated state to remove carbon, nitrogen and phosphorus; the mixed liquor of the anoxic pool 3 enters the second alternating pool 2 through the fourth mixed liquor outlet 335 and the second mixed liquor inlet 213, and the second alternating pool 2 continues to precipitate water to complete the mud-water separation. In this embodiment, the duration of this process is 60 minutes.

[0068] Process three:

[0069] The first raw water inlet 111 is closed, the second raw water inlet 211 is closed, the third raw water inlet 331 is opened, the first supernatant liquid outlet 121 is closed, the second supernatant liquid outlet 221 is opened, the first aeration unit 13 is working, the second aeration unit 23 is not working, the third aeration unit 31 is not working, the first mixed liquid valve 334 is closed, the second mixed liquid valve 336 is opened, the third mixed liquid valve 338 is closed, the fourth mixed liquid valve 340 is closed, the agitator 32 is opened, the first mud discharge port 141 is closed, and the second mud discharge port 241 is closed.

[0070] The first alternating pool 1 stops taking in water and maintains aeration to complete the degradation of the remaining pollutants; the anoxic pool 3 starts taking in water and stirring at the same time to remove the remaining nitrate nitrogen by denitrification; the mixed liquid in the anoxic pool 3 enters the second alternating pool 2 through the fourth mixed liquid outlet 335 and the second mixed liquid inlet 213, and the mud and water separation is completed in the second alternating pool 2. In this embodiment, the duration of this process is 30 minutes.

[0071] Process 4:

[0072] The first raw water inlet 111 is closed, the second raw water inlet 211 is closed, the third raw water inlet 331 is opened, the first supernatant liquid outlet 121 is closed, the second supernatant liquid outlet 221 is opened, the first aeration unit 13 is not working, the second aeration unit 23 is not working, the third aeration unit 31 is working, the first mixed liquid valve 334 is closed, the second mixed liquid valve 336 is opened, the third mixed liquid valve 338 is closed, the fourth mixed liquid valve 340 is closed, the agitator 32 is closed, the first mud discharge port 141 is opened, and the second mud discharge port 241 is closed.

[0073] The first alternating pool 1 stops aeration and enters the sedimentation stage, and the first mud outlet 141 is opened to discharge the remaining sludge in the first alternating pool 1; the aeration pool 3 stops stirring and starts aeration; the mud-water mixture in the aeration pool 3 enters the second alternating pool 2 to complete the mud-water separation. In this embodiment, this process lasts for 30 minutes.

[0074] Process 5:

[0075] The first raw water inlet 111 is closed, the second raw water inlet 211 is opened, the third raw water inlet 331 is closed, the first supernatant liquid outlet 121 is opened, the second supernatant liquid outlet 221 is closed, the first aeration unit 13 is not working, the second aeration unit 23 is not working, the third aeration unit 31 is working, the first mixed liquid valve 334 is opened, the second mixed liquid valve 336 is closed, the third mixed liquid valve 338 is closed, the fourth mixed liquid valve 340 is opened, the agitator 32 is closed, the first mud discharge port 141 is closed, and the second mud discharge port 241 is closed.

[0076] The raw water enters the bottom of the second alternating pool 2 through the second water distribution unit 21, and contacts the sludge at the bottom. The sludge at the bottom is in a high-load feast environment, and denitrification and phosphorus release by polyphosphate bacteria occur during this process; the supernatant at the top of the second alternating pool 2 enters the anoxic pool 3 through the second mixed liquid outlet 243 and the fourth mixed liquid inlet 339, and contacts the sludge in the anoxic pool 3; the anoxic pool 3 stops taking in water and maintains the aeration state to complete the degradation of pollutants; the mixed liquid of the anoxic pool 3 enters the first alternating pool 1 through the third mixed liquid outlet 333 and the first mixed liquid inlet 113, and the mixed liquid is precipitated in the first alternating pool 1 to achieve mud-water separation. The supernatant in the first alternating pool 1 is collected by the first supernatant collection unit 12 and discharged from the system through the first supernatant outlet 121, and the sludge in the first alternating pool 1 is in a hungry state. In this embodiment, the duration of this process is 60 minutes.

[0077] Process six:

[0078] The first raw water inlet 111 is closed, the second raw water inlet 211 is opened, the third raw water inlet 331 is closed, the first supernatant liquid outlet 121 is opened, the second supernatant liquid outlet 221 is closed, the first aeration unit 13 is not working, the second aeration unit 23 is working, the third aeration unit 31 is working, the first mixed liquid valve 334 is opened, the second mixed liquid valve 336 is closed, the third mixed liquid valve 338 is closed, the fourth mixed liquid valve 340 is opened, the agitator 32 is closed, the first mud discharge port 141 is closed, and the second mud discharge port 241 is closed.

[0079] The second alternating pool 2 is aerated, and the muddy-water mixture in the second alternating pool 2 enters the anoxic pool 3 through the second mixed liquid outlet 243 and the fourth mixed liquid inlet 339; the anoxic pool 3 is in an aerated state; the mixed liquid in the anoxic pool 3 enters the first alternating pool 1 through the third mixed liquid outlet 333 and the first mixed liquid inlet 113 to complete the mud-water separation. This process lasts for 60 minutes.

[0080] Process seven:

[0081] The first raw water inlet 111 is closed, the second raw water inlet 211 is closed, the third raw water inlet 331 is opened, the first supernatant liquid outlet 121 is opened, the second supernatant liquid outlet 221 is closed, the first aeration unit 13 does not work, the second aeration unit 23 works, the third aeration unit 31 does not work, the first mixed liquid valve 334 is opened, the second mixed liquid valve 336 is closed, the third mixed liquid valve 338 is closed, the fourth mixed liquid valve 340 is closed, the agitator 32 is opened, the first mud discharge port 141 is closed, and the second mud discharge port 241 is closed.

[0082] The second alternating tank 2 stops taking in water and continues aeration to complete the degradation of the remaining pollutants; the anoxic tank 3 starts taking in water and starts stirring at the same time to remove the remaining nitrate nitrogen by denitrification; the mixed liquid from the anoxic tank 3 enters the first alternating tank 1 to complete the mud-water separation, and this stage lasts for 30 minutes.

[0083] Process eight:

[0084] The first raw water inlet 111 is closed, the second raw water inlet 211 is closed, the third raw water inlet 331 is opened, the first supernatant liquid outlet 121 is opened, the second supernatant liquid outlet 221 is closed, the first aeration unit 13 is not working, the second aeration unit 23 is not working, the third aeration unit 31 is working, the first mixed liquid valve 334 is opened, the second mixed liquid valve 336 is closed, the third mixed liquid valve 338 is closed, the fourth mixed liquid valve 340 is closed, the agitator 32 is closed, the first mud discharge port 141 is closed, and the second mud discharge port 241 is opened.

[0085] The second alternating tank 2 stops aeration and enters the sedimentation stage, and opens the second mud outlet 241 to discharge the remaining sludge; the aeration tank 3 stops stirring and enters the aeration state, and the mud-water mixture in the aeration tank 3 enters the first alternating tank 1 to complete the mud-water separation. In this embodiment, this process lasts for 30 minutes.

[0086] Specifically, by repeating the above process steps, aerobic granular sludge cultivation can be continuously performed. Processes five to eight repeat the working process of processes one to four, except that the water flow direction is switched from the first alternating pool 1 → anoxic pool 3 → second alternating pool 2 to the second alternating pool 2 → anoxic pool 3 → first alternating pool 1. The first water distribution pipe 114 and the second water distribution pipe 214 are used to distribute raw water to the bottom of the first alternating pool 1 and the second alternating pool 2, so that the incoming water and the sludge can be contacted preferentially, creating a high-load feast environment for the bottom sludge. The sludge in the first alternating pool 1 and the second alternating pool 2 is alternately in a feast and starvation state, forming a feast-starvation alternating environment in time and space, which is conducive to the secretion of EPS and promotes the formation of granular sludge. The first alternating pool 1 and the second alternating pool 2 are intermittently in anaerobic, aerobic and anoxic states; the anoxic pool 3 is intermittently in aerobic and anoxic states; there is no need to set up a sludge return and nitrification liquid return system, which can effectively achieve the removal of pollutants such as carbon, nitrogen, and phosphorus in sewage, reduce power equipment, and reduce energy consumption; the sludge does not need to pass through the sludge pump and the return pump, avoiding the damage of the granular sludge structure by power equipment such as the return pump. The first alternating pool 1 and the second alternating pool 2 are alternately fed with water, and the anoxic pool 3 is alternately aerated and stirred to achieve alternating operation of anaerobic, aerobic, and anoxic conditions, which helps to improve the performance of nitrogen removal and phosphorus removal. The first alternating pool 1 and the second alternating pool 2 are alternately used as sedimentation tanks and reaction tanks, and there is no need to set up a secondary sedimentation tank separately, which improves the utilization rate of the structure.

[0087] In this embodiment, the first water distribution unit 11 and the second water distribution unit 21 are both water distribution weirs.

[0088] Specifically, the water distribution weir is an existing technology, and the specific structure and working principle are not described in detail.

[0089] Optionally, the first supernatant collection unit 12 and the second supernatant collection unit 22 are both air weirs;

[0090] The first supernatant collection unit 12 is further provided with a first air inlet 144 and a first air outlet 146. The first air inlet 144 is provided with a first air inlet valve 145, and the first air outlet 146 is provided with a first air outlet valve 147.

[0091] The second supernatant collecting unit 22 is provided with a second air inlet 244 and a second air outlet 246 . The second air inlet 244 is provided with a second air inlet valve 245 , and the second air outlet 246 is provided with a second air outlet valve 247 .

[0092] Specifically, the air weir is an existing technology, including a cover plate and a water outlet weir. A closed space is formed between the cover plate and the water outlet weir. The air pressure in the closed space is changed by exhausting and inletting air, thereby achieving water collection and interruption of water collection by the air weir.

[0093] In this embodiment, the alternating continuous flow aerobic granular sludge culture system also includes:

[0094] The air compressor 5 is connected to the first intake valve 145 and the second intake valve 245 .

[0095] Specifically, the air pressure in the air weir is changed by the air compressor 5 to achieve water collection and interruption of water collection in the air weir.

[0096] Optionally, the first supernatant liquid outlet 121 is provided with a first supernatant liquid outlet valve 122;

[0097] The first mud discharge port 141 is provided with a first mud discharge valve 142;

[0098] The second supernatant liquid outlet 221 is provided with a second supernatant liquid outlet valve 222;

[0099] The second mud discharge port 241 is provided with a second mud discharge valve 242 .

[0100] Specifically, the first supernatant outlet valve 122 can realize the opening and closing of the first supernatant outlet 121, the first mud discharge valve 142 can realize the opening and closing of the first mud discharge outlet 141, the second mud discharge valve 242 can realize the opening and closing of the second mud discharge outlet 241, and the second supernatant outlet valve 222 can realize the opening and closing of the second supernatant outlet 221.

[0101] In this embodiment, the alternating continuous flow aerobic granular sludge cultivation system further includes:

[0102] A raw water pool 4 is provided with a water pump 41, and the water pump 41 is connected to the first raw water inlet 111, the second raw water inlet 211 and the third raw water inlet 331 through a water supply pipeline 42. The first raw water inlet 111 is provided with a first raw water inlet valve 112, the second raw water inlet 211 is provided with a second raw water inlet valve 212, and the third raw water inlet 331 is provided with a third raw water inlet valve 332.

[0103] Specifically, the raw water tank 4 is used to store raw water, the water pump 41 is used to transport raw water to the first alternating tank 1, the second alternating tank 2 and the oxygen tank 3, the first raw water inlet valve 112 can realize the opening and closing of the first raw water inlet 111, the second raw water inlet valve 212 can realize the opening and closing of the second raw water inlet 211, and the third raw water inlet valve 332 can realize the opening and closing of the third raw water inlet 331.

[0104] In this embodiment, the first aeration unit 13 , the second aeration unit 23 and the third aeration unit 31 are all aeration disks. The first aeration unit 13 is provided with a first aeration inlet 131 , the second aeration unit 23 is provided with a second aeration inlet 231 , and the third aeration unit 31 is provided with a third aeration inlet 311 .

[0105] The first aeration unit 13 is arranged at the bottom of the first alternating pool 1;

[0106] The second aeration unit 23 is arranged at the bottom of the second alternating pool 2;

[0107] The third aeration unit 31 is disposed at the bottom of the aeration tank 3 .

[0108] Specifically, an aeration plate is a prior art technology that is disposed at the bottom of a container and is used to disperse air into the water to provide sufficient oxygen for microorganisms to degrade pollutants.

[0109] Optionally, the alternating continuous flow aerobic granular sludge cultivation system further comprises:

[0110] The blower 6 is connected to the first aeration inlet 131 , the second aeration inlet 231 and the third aeration inlet 311 . The first aeration inlet 131 is provided with a first aeration valve 132 , the second aeration inlet 231 is provided with a second aeration valve 232 , and the third aeration inlet 311 is provided with a third aeration valve 322 .

[0111] Optionally, the alternating continuous flow aerobic granular sludge cultivation system also includes a control unit 7, which is electrically connected to the first mixed liquor valve 334, the second mixed liquor valve 336, the third mixed liquor valve 338, the fourth mixed liquor valve 340, the first air inlet valve 145, the first exhaust valve 147, the second air inlet valve 245, the second exhaust valve 247, the air compressor 5, the first supernatant outlet valve 122, the first sludge discharge valve 142, the second supernatant outlet valve 222, the second sludge discharge valve 242, the water pump 41, the first raw water inlet valve 112, the second raw water inlet valve 212, the third raw water inlet valve 332, the blower 6, the first aeration valve 132, the second aeration valve 232, the third aeration valve 322 and the agitator 32.

[0112] like Figure 2 As shown, this embodiment also provides an alternating continuous flow aerobic granular sludge cultivation method, using the alternating continuous flow aerobic granular sludge cultivation system in this embodiment, including the following steps:

[0113] Step 1: Introduce sewage into the first alternating tank 1 and distribute it to the bottom to contact with sludge; introduce sewage from the top of the first alternating tank 1 into the anoxic tank 3 for nitrogen and phosphorus removal; introduce the mixed liquid of the anoxic tank 3 into the second alternating tank 2 for precipitation; discharge the supernatant of the second alternating tank 2 from the system; and continue to operate for 60 minutes;

[0114] Step 2: The first alternating tank 1 is aerated and the mud-water mixture is introduced into the anoxic tank 3 for pollutant degradation; the mixed liquid in the anoxic tank 3 is introduced into the second alternating tank 2 for sedimentation; and the operation is continued for 60 minutes;

[0115] Step 3: the first alternating pool 1 stops taking in water and continues aeration to complete the degradation of the remaining pollutants; the sewage is introduced into the anoxic pool 3 and stirred to remove the remaining nitrate nitrogen by denitrification; the mixed liquid in the anoxic pool 3 is introduced into the second alternating pool 2 for precipitation, and the operation is continued for 30 minutes;

[0116] Step 4: the first alternating tank 1 stops aeration to carry out sedimentation, and the remaining sludge after sedimentation is discharged; the aerobic tank 3 stops stirring and aerates; the sludge-water mixture in the aerobic tank 3 is introduced into the second alternating tank 2 for sedimentation, and the operation is continued for 30 minutes;

[0117] Step 5: Introduce sewage into the second alternating tank 2 and distribute it to the bottom to contact with sludge; stop the water intake of the anoxic tank 3 and continue aeration to complete the degradation of pollutants; introduce the mixed liquid of the anoxic tank 3 into the first alternating tank 1 and precipitate, discharge the supernatant of the first alternating tank 1 from the system, and continue to operate for 30 minutes;

[0118] Step 6: The second alternating pool 2 is aerated and the mud-water mixture is introduced into the anoxic pool 3; the mixed liquid of the anoxic pool 3 is introduced into the first alternating pool 1 for sedimentation, and the operation is continued for 60 minutes;

[0119] Step 7: the second alternating pool 2 stops taking in water and continues aeration to complete the degradation of the remaining pollutants; the sewage is introduced into the anoxic pool 3 and stirred to remove the remaining nitrate nitrogen by denitrification; the mixed liquid in the anoxic pool 3 is introduced into the first alternating pool 1 for precipitation, and the operation is continued for 60 minutes;

[0120] Step 8: the second alternating tank 2 stops aeration to carry out sedimentation and discharges the remaining sludge after sedimentation; the aerobic tank 3 stops stirring and starts aeration; the sludge-water mixture in the aerobic tank 3 is introduced into the first alternating tank 1 for sedimentation, and the operation continues for 30 minutes;

[0121] Step 9: Repeat steps 1 to 8 in a loop.

[0122] Furthermore, this embodiment uses the alternating continuous flow aerobic granular sludge cultivation method to treat the raw water of a water plant's primary sedimentation tank. The water quality indicators of raw water COD, ammonia nitrogen, TN and TP are 150-400 mg / L, 25-40 mg / L, 30-50 mg / L and 3-5 mg / L respectively. By inoculating activated sludge and adopting an alternating operation mode, sludge granulation is achieved in 60 days, and the sludge particle size reaches 208.5 μm. The sludge particle size distribution of the biological pool during stable operation is shown in the figure below: Figure 3 As shown, the effluent COD, ammonia nitrogen, TN and TP concentrations are 18-30 mg / L, 0.3-1 mg / L, 12-18 mg / L and 0.1-0.5 mg / L respectively.

[0123] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An alternating continuous flow aerobic granular sludge culture system, characterized in that: include: A first alternating pool (1), wherein the first alternating pool (1) is provided with a first water distribution unit (11), a first supernatant liquid collecting unit (12) and a first aeration unit (13); the first water distribution unit (11) is arranged at the top of the first alternating pool (1); a plurality of first water distribution pipes (114) are connected below the first water distribution unit (11); the first water distribution pipes (114) extend to the bottom of the first alternating pool (1); the first water distribution unit (11) is also provided with a first raw water inlet (111) and a first mixed liquid inlet (113); the first supernatant liquid collecting unit (12) is provided with a first supernatant liquid outlet (121); and the first alternating pool (1) is also provided with a first mud discharge port (141) and a first mixed liquid outlet (143); A second alternating pool (2), wherein the second alternating pool (2) is provided with a second water distribution unit (21), a second supernatant collection unit (22) and a second aeration unit (23); a plurality of second water distribution pipes (214) are connected below the second water distribution unit (21); the second water distribution pipes (214) extend to the bottom of the second alternating pool (2); the second water distribution unit (21) is further provided with a second raw water inlet (211) and a second mixed liquid inlet (213); the second supernatant collection unit (22) is provided with a second supernatant outlet (221); and the second alternating pool (2) is further provided with a second mud discharge outlet (241) and a second mixed liquid outlet (243); The aerobic tank (3) is provided with an agitator (32), a third aeration unit (31), a third raw water inlet (331), a third mixed liquor outlet (333), a fourth mixed liquor outlet (335), a third mixed liquor inlet (337) and a fourth mixed liquor inlet (339), wherein the third mixed liquor outlet (333) is connected to the first mixed liquor inlet (113) via a first mixed liquor valve (334), the fourth mixed liquor outlet (335) is connected to the second mixed liquor inlet (213) via a second mixed liquor valve (336), the third mixed liquor inlet (337) is connected to the first mixed liquor outlet (143) via a third mixed liquor valve (338), and the fourth mixed liquor inlet (339) is connected to the second mixed liquor outlet (243) via a fourth mixed liquor valve (340).

2. The alternating continuous flow aerobic granular sludge cultivation system according to claim 1, characterized in that: The first water distribution unit (11) and the second water distribution unit (21) are both water distribution weirs.

3. The alternating continuous flow aerobic granular sludge cultivation system according to claim 1, characterized in that: The first supernatant collection unit (12) and the second supernatant collection unit (22) are both air weirs; The first supernatant collection unit (12) is further provided with a first air inlet (144) and a first air outlet (146); the first air inlet (144) is provided with a first air inlet valve (145); and the first air outlet (146) is provided with a first air outlet valve (147); The second supernatant collection unit (22) is provided with a second air inlet (244) and a second air outlet (246); the second air inlet (244) is provided with a second air inlet valve (245); and the second air outlet (246) is provided with a second air outlet valve (247).

4. The alternating continuous flow aerobic granular sludge cultivation system according to claim 3, characterized in that: Also includes: An air compressor (5), the air compressor (5) being connected to the first air intake valve (145) and the second air intake valve (245).

5. The alternating continuous flow aerobic granular sludge cultivation system according to claim 4, characterized in that: The first supernatant liquid outlet (121) is provided with a first supernatant liquid outlet valve (122); The first mud discharge port (141) is provided with a first mud discharge valve (142); The second supernatant liquid outlet (221) is provided with a second supernatant liquid outlet valve (222); The second mud discharge port (241) is provided with a second mud discharge valve (242).

6. The alternating continuous flow aerobic granular sludge cultivation system according to claim 5, characterized in that: Also includes: A raw water pool (4), wherein a water pump (41) is provided in the raw water pool (4), and the water pump (41) is connected to the first raw water inlet (111), the second raw water inlet (211) and the third raw water inlet (331) through a water supply pipeline (42), the first raw water inlet (111) is provided with a first raw water inlet valve (112), the second raw water inlet (211) is provided with a second raw water inlet valve (212), and the third raw water inlet (331) is provided with a third raw water inlet valve (332).

7. The alternating continuous flow aerobic granular sludge cultivation system according to claim 6, characterized in that: The first aeration unit (13), the second aeration unit (23) and the third aeration unit (31) are all aeration disks; the first aeration unit (13) is provided with a first aeration inlet (131); the second aeration unit (23) is provided with a second aeration inlet (231); and the third aeration unit (31) is provided with a third aeration inlet (311).

8. The alternating continuous flow aerobic granular sludge cultivation system according to claim 7, characterized in that: Also includes: A blower (6), the blower (6) being connected to the first aeration inlet (131), the second aeration inlet (231) and the third aeration inlet (311), the first aeration inlet (131) being provided with a first aeration valve (132), the second aeration inlet (231) being provided with a second aeration valve (232), and the third aeration inlet (311) being provided with a third aeration valve (322).

9. The alternating continuous flow aerobic granular sludge cultivation system according to claim 8, characterized in that: The invention also comprises a control unit (7), wherein the control unit (7) is electrically connected to the first mixed liquid valve (334), the second mixed liquid valve (336), the third mixed liquid valve (338), the fourth mixed liquid valve (340), the first air inlet valve (145), the first air exhaust valve (147), the second air inlet valve (245), the second air exhaust valve (247), the air compressor (5), the first supernatant liquid outlet valve (122), the first mud discharge valve (142), the second supernatant liquid outlet valve (222), the second mud discharge valve (242), the water pump (41), the first raw water inlet valve (112), the second raw water inlet valve (212), the third raw water inlet valve (332), the blower (6), the first aeration valve (132), the second aeration valve (232), the third aeration valve (322) and the agitator (32).

10. An alternating continuous flow aerobic granular sludge cultivation method, using the alternating continuous flow aerobic granular sludge cultivation system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: introducing sewage into the first alternating tank (1) and distributing it to the bottom, introducing sewage at the top of the first alternating tank (1) into the anoxic tank (3), introducing the mixed liquid of the anoxic tank (3) into the second alternating tank (2), and discharging the supernatant of the second alternating tank (2) out of the system, and continuously operating for a first set time; Step 2: The first alternating tank (1) is aerated and the mud-water mixture is introduced into the aerobic tank (3), and the mixture in the aerobic tank (3) is introduced into the second alternating tank (2), and the operation is continued for a second set time; Step 3: the first alternating tank (1) stops taking in water but continues aeration, the sewage is introduced into the anoxic tank (3) and stirred, the mixed liquid in the anoxic tank (3) is introduced into the second alternating tank (2), and the operation is continued for a third set time; Step 4: the first alternating tank (1) stops aeration and discharges the remaining sludge after sedimentation, the aerobic tank (3) stops stirring and performs aeration, and the sludge-water mixture in the aerobic tank (3) is introduced into the second alternating tank (2), and the operation continues for a fourth set time; Step 5: introducing sewage into the second alternating tank (2) and distributing it to the bottom, stopping the intake of water into the anoxic tank (3) and continuing aeration, introducing the mixed liquid of the anoxic tank (3) into the first alternating tank (1), and discharging the supernatant of the first alternating tank (1) out of the system, and continuing the operation for a fifth set time; Step 6: the second alternating tank (2) is aerated and the mud-water mixture is introduced into the aerobic tank (3), and the mixture of the aerobic tank (3) is introduced into the first alternating tank (1), and the operation is continued for a sixth set time; Step 7: the second alternating tank (2) stops taking in water but continues aeration, the sewage is introduced into the anoxic tank (3) and stirred, the mixed liquid in the anoxic tank (3) is introduced into the first alternating tank (1), and the operation continues for the seventh set time; Step 8: the second alternating tank (2) stops aeration and discharges the remaining sludge after sedimentation, the aerobic tank (3) stops stirring and starts aeration, and the sludge-water mixture in the aerobic tank (3) is introduced into the first alternating tank (1), and the operation continues for an eighth set time; Step 9: Repeat steps 1 to 8 in a loop.

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