MCC multi-selection combined sewage treatment system and method

Abstract

The invention relates to an MCC multi-selection combined sewage treatment system and method. The MCC multi-selection combined sewage treatment system comprises a first selection area, a second selection area, a third selection area, a fourth selection area, a fifth selection area, a sixth selection area and a combination area, the first selection area is provided with a first water impeller, a second water impeller, a first gas stripping device, a second gas stripping device and an adjusting weir gate; the third selection area is provided with a third gas stripping device; the fourth selection area is provided with a fourth gas stripping device; a fifth gas stripping device is arranged in the fifth selection area; the fourth selection area is provided with a third water impeller; and perforated sludge discharge pipes are arranged at the bottoms of the second selection area and the third selection area. The invention also relates to a sewage treatment method using the MCC multi-selection combined sewage treatment system. The sewage treatment method comprises a general mode, an efficient mode and an enhancement mode. According to the invention, multiple selection modes are realized, and the treatment requirement of unstable water quality is met; different modes are selected according to different water quality and water quantity conditions, and the stable, economical and energy-saving operation effects of the system are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an MCC multiple selection combined sewage treatment system and method. Background Art

[0002] At present, sewage treatment plants usually use the traditional activated sludge method for nitrogen and phosphorus removal, but traditional biological nitrogen and phosphorus removal processes such as A / O, A2 / O, SBR, UCT, MBR, etc. generally have certain limitations.

[0003] The defects of the prior art are mainly reflected in the following aspects:

[0004] 1. Single operation mode: Because traditional processes rely on the front-end pretreatment regulation system to deal with large changes in water quality and water volume, if the pretreatment is not ideal or the pretreatment retention time is not designed sufficiently, it will cause a great impact on the biochemical system, especially when it comes to industrial sewage. The industrial sewage diversion is not perfect. Generally, sewage treatment plants are prone to sludge swelling and substandard effluent when mixed with industrial sewage. Industrial park sewage treatment plants often face problems such as large changes in incoming water quality and unstable water volume, which affect the normal operation of the system.

[0005] 2. In traditional processes, nitrifying bacteria are autotrophic aerobic bacteria with slow reproduction speed and long generation time, while polyphosphate bacteria have a short generation time. Phosphorus removal is achieved by removing excess sludge. Therefore, in order to ensure good phosphorus removal effects, the system must operate with a short sludge age. This leads to a contradiction in the operation of the system in terms of sludge age control for nitrogen removal and phosphorus removal.

[0006] 3. Since carbon source is the largest nutrient element required for microbial growth, in the process of nitrogen and phosphorus removal, carbon source is mainly consumed in denitrification, phosphorus release and normal metabolism of heterotrophic bacteria. The reaction rates of denitrification and phosphorus release are related to the amount of organic fatty acids hydrolyzed from carbon source in the influent, so there is a competitive relationship between the two for carbon source.

[0007] 4. Since traditional biological nitrogen removal and phosphorus removal processes have certain requirements for site area, most of them require secondary sedimentation tanks and occupy a large area; at the same time, as modern sewage treatment plants have increasingly higher requirements for effluent quality and water quantity, it is often necessary to upgrade the original treatment process. For example, some old industrial parks often have tight land use and many restrictions, making it difficult to carry out design. Summary of the invention

[0008] In view of the above problems, the present invention provides an MCC multiple-selection combined sewage treatment system and method, the purpose of which is to realize multiple selection modes to meet the treatment requirements of unstable water quality; different modes are selected according to different water quality and water quantity conditions to achieve system stability and economical and energy-saving operation effects.

[0009] To solve the above problems, the technical solution provided by the present invention is:

[0010] The MCC multiple selection combined sewage treatment system and method comprises a first selection area, a second selection area, a third selection area, a fourth selection area, a fifth selection area, a sixth selection area, and a combination area, wherein: the combination area is arranged in the center of the sewage treatment system; the first selection area, the second selection area, the third selection area, the fourth selection area, the fifth selection area, and the sixth selection area are respectively adjacent to the combination area, and are arranged in sequence in a clockwise direction around the combination area; the inlet water is controlled by a valve to enter the first selection area or the second selection area;

[0011] The first selection area is provided with a first flowmaker, a second flowmaker, a first air stripping device, a second air stripping device and an adjusting weir for controlling the water flow direction and the amount of backflow; the first flowmaker, the first air stripping device and the adjusting weir are arranged on the adjacent sides of the first selection area and the second selection area; the second flowmaker and the second air stripping device are arranged on the adjacent sides of the first selection area and the sixth selection area;

[0012] A third gas stripping device is provided inside the third selection zone and on the adjacent side of the fourth selection zone; a fourth gas stripping device is provided inside the fourth selection zone and on the adjacent side of the fifth selection zone; a fifth gas stripping device is provided inside the fifth selection zone and on the adjacent side of the fourth selection zone; a third flow promoter is provided on the adjacent side of the fourth selection zone and the combination zone;

[0013] The first selection area, the second selection area, the third selection area, the fourth selection area, the fifth selection area, and the sixth selection area are respectively provided with an aeration device interface for installing an integral lifting aeration device;

[0014] The bottoms of the second selection area and the third selection area are provided with perforated mud discharge pipes.

[0015] Preferably, the total gas consumption of the first gas stripping device, the second gas stripping device, the third gas stripping device, the fourth gas stripping device and the fifth gas stripping device accounts for 5%-10% of the total gas consumption.

[0016] Preferably, the residence time of sewage in each block of the sewage treatment system is adjusted according to the difference in influent water quality; when treating conventional sewage, the residence time of sewage in the first selection area is 3 hours, the residence time in the second selection area and the sixth selection area is 2 hours respectively, the residence time in the third selection area and the fifth selection area is 8 hours respectively, the residence time in the fourth selection area is 1 hour, and the total residence time of sewage in the system is 16 hours; the surface load range of the combined area is 1m 3 / m 2·h~1.2m 3 / m 2 ·h.

[0017] Preferably, the local aeration amount of the integral lifting aeration device is adjusted by adjusting the valve or moving the position of the integral lifting aeration device; the adjustment range of dissolved oxygen in the aeration zone is 0.3mg / l to 2mg / l; the integral lifting aeration device is reserved with a bronchial pipe and a limit guide rod, and the position is adjusted according to actual needs. The bronchial pipe is provided with the regulating valve.

[0018] Preferably, a precipitator is provided inside the combination zone; the bottom of the combination zone is connected to the first selection zone and the fourth selection zone respectively;

[0019] The effective water depth of the biological pool in the combination area is 6 meters; a combination area filler is provided in the combination area; the bottom of the combination area filler is 2 meters away from the bottom of the pool, the top is 1.5 meters away from the liquid surface, and the filler layer is 2.5 meters high; the combination area filler is a labyrinth-type filler; the effluent is collected through the top outlet trough of the combination area and then aggregated to the outlet channel and then discharged to subsequent units.

[0020] The sewage treatment method using the MCC multiple selection combined sewage treatment system includes a general mode, a high-efficiency mode and an enhanced mode; when the system water inlet index reaches the manually preset general mode activation condition, the general mode is activated; when the system water inlet index reaches the manually preset high-efficiency mode activation condition, the high-efficiency mode is activated; when the system water inlet index reaches the manually preset enhanced mode activation condition, the enhanced mode is activated.

[0021] Preferably, the general mode comprises the following steps:

[0022] Sa1. The overall lifting aeration device is installed on the aeration device interface of the third selection zone and the fifth selection zone;

[0023] Sa2 mixed liquid from the first selection area until the water inlet reaches the manually preset target water inlet;

[0024] Sa3. The regulating weir is fully opened, and the first flow generator and the second flow generator are started to push the mixed liquid into the second selection area and the sixth selection area respectively, until the water volume of the second selection area and the sixth selection area reaches half of the target water inflow;

[0025] Sa4. Control the sludge concentration, mixed liquor reflux ratio, and gas-water ratio of the first selection zone, the second selection zone, the third selection zone, the fourth selection zone, the fifth selection zone, and the sixth selection zone to achieve general mode control parameters;

[0026] Sa5. Control the dissolved oxygen in the second selection zone and the sixth selection zone to achieve artificially preset anaerobic conditions;

[0027] Sa6. Controlling the first selection area and the fourth selection area to achieve artificially preset hypoxic conditions;

[0028] Sa7. Open the overall lifting aeration device of the third selection zone and the fifth selection zone until the dissolved oxygen in the third selection zone and the fifth selection zone reaches the manually preset aerobic conditions;

[0029] Sa8. The first selection area, the second selection area, and the third selection area are the first group, and the first selection area, the sixth selection area, and the fifth selection area are the second group, and the system forms two sets of inverted AAO processes in parallel;

[0030] Sa9. The mixed liquid flows back to the combination area for mud and water separation.

[0031] Preferably, the high efficiency mode comprises the following steps:

[0032] Sb1. The overall lifting aeration device is installed on the aeration device interface of the second selection area, the third selection area, the fifth selection area, and the sixth selection area;

[0033] Sb2. The mixed liquid is inletted from the first selection zone until the inlet volume reaches the manually preset target inlet volume;

[0034] Sb3. Start the first flow booster and the second flow booster to push the mixed solution into the second selection zone and the sixth selection zone, respectively;

[0035] Sb4. Control the sludge concentration, the mixed liquor reflux ratio, and the gas-water ratio of the first selection area, the second selection area, the third selection area, the fourth selection area, the fifth selection area, and the sixth selection area to achieve high-efficiency mode control parameters;

[0036] Sb5. When the mixed liquor reflux ratio reaches 10:1, the first gas stripping device and the second gas stripping device are opened; when the mixed liquor reflux ratio reaches 20:1, the third gas stripping device and the fifth gas stripping device are opened;

[0037] Sb6. The first selection zone is not aerated until the anaerobic conditions preset manually are reached;

[0038] Sb7. Control the second selection zone, the third selection zone, the fifth selection zone, the sixth selection zone of the overall lifting aeration device, so that they all reach the artificial preset facultative oxygen conditions;

[0039] Sb8. The fourth selection area is set as a water distribution area, and the third flow pusher is turned on to push the mixed liquid to the combination area.

[0040] Preferably, the enhanced mode comprises the following steps:

[0041] Sc1. The overall lifting aeration device is installed on the aeration device interface of the first selection zone, the third selection zone, and the fifth selection zone;

[0042] Sc2. The mixed liquid enters the second selection area until the water inflow reaches the manually preset target water inflow;

[0043] Sc3. Close the regulating weir and the first flow generator to allow the mixed liquid to flow through the third selection zone;

[0044] The second selection zone and the third selection zone are not aerated. When the second selection zone and the third selection zone reach the anaerobic condition, a hydrolysis reaction occurs to convert the difficult-to-biodegrade macromolecules into easily-biodegradable small molecules, which is beneficial to subsequent unit treatment. The hydrolyzed sludge is discharged through the perforated sludge discharge pipe;

[0045] The integral lifting aeration device of the third selection zone aerates until the third selection zone reaches the aerobic condition to condition the high-concentration wastewater;

[0046] When treating special wastewater, the third selection area is used to pre-treat the wastewater by placing fillers, carriers, and bacteria;

[0047] Sc4. Control the sludge concentration, the mixed liquor reflux ratio, and the gas-water ratio of the first selection zone, the second selection zone, the third selection zone, the fourth selection zone, the fifth selection zone, and the sixth selection zone to achieve enhanced mode control parameters;

[0048] Sc5. The mixed solution flows sequentially through the fourth selection area, the fifth selection area, the sixth selection area, and the first selection area; controlling the fourth selection area and the sixth selection area to reach the anoxic condition;

[0049] Sc.6 The mixed liquid enters the combination zone; the clean water in the combination zone flows out from the overflow tank above, and the mixed liquid and sludge flow back to the fourth selection zone.

[0050] Preferably, the general mode activation condition is: influent COD≤300mg / l, TN≤30mg / l, B / C≥0.3; the high efficiency mode activation condition is: influent 300mg / l<COD≤400mg / l, 30mg / l<TN≤60mg / l, B / C≥0.3;

[0051] The enhancement mode activation condition is: the critical design condition of the system is reached and B / C is less than 0.3.

[0052] The general mode control parameters are: the sludge concentration of the first selection area, the second selection area, the third selection area, the fourth selection area, the fifth selection area, and the sixth selection area is in the range of 3000 mg / l to 4000 mg / l; the mixed liquor reflux ratio is in the range of 2:1 to 3:1; the gas-water ratio is in the range of 6:1 to 8:1;

[0053] The high-efficiency mode control parameters are: the sludge concentration of the first selection area, the second selection area, the third selection area, the fourth selection area, the fifth selection area, and the sixth selection area is in the range of 6 g / l to 8 g / l; the mixed liquor reflux ratio is in the range of 10:1 to 20:1; the gas-water ratio is in the range of 4:1 to 6:1;

[0054] The control parameters of the enhanced mode are: the sludge concentration of the first selection area, the second selection area, the third selection area, the fourth selection area, the fifth selection area, and the sixth selection area is in the range of 3g / l to 4g / l; the mixed liquor reflux ratio is 3:1. The gas-water ratio is in the range of 6:1 to 10:1;

[0055] The specific condition of the anaerobic condition is that the dissolved oxygen is less than 0.2 mg / l;

[0056] The specific condition of the anoxic condition is that the range of dissolved oxygen is 0.2mg / l-0.5mg / l;

[0057] The specific condition of the aerobic condition is that the dissolved oxygen reaches 2 mg / l;

[0058] The specific condition of the anaerobic condition is that the range of the dissolved oxygen is 0.3 mg / l to 1 mg / l.

[0059] Compared with the prior art, the present invention has the following advantages:

[0060] 1. Since the present invention forms three different treatment modes by combining different selection areas, it can cope with various high COD, high TN and low biochemical wastewater treatment needs.

[0061] 2. Since the general mode of the present invention is two sets of parallel inverted AAO processes, when the water volume is low, a single set of operation can be controlled by a weir gate, thereby saving energy consumption.

[0062] 3. In the high-efficiency mode of the present invention, the aeration zone adopts the simultaneous nitrification and denitrification microbial technology to control nitrification at the nitrite stage, and can directly use nitrite nitrogen as the electron acceptor; and the entire denitrification process can be achieved through a short-range nitrification and denitrification process, and the simultaneous nitrification and denitrification process is short, thereby saving carbon sources and reducing oxygen consumption.

[0063] 4. In the high efficiency mode of the present invention, the consumption of carbon source can be reduced by 40% and oxygen by 25%, thereby greatly saving operating costs.

[0064] 5. Because the present invention forms three-stage AO for difficult-to-degrade, high-concentration wastewater in the enhanced mode, the first-stage AO regulates and modifies the high-concentration difficult-to-degrade wastewater, thereby reducing the concentration of pollutants and improving biodegradability, which is beneficial for the subsequent units to process.

[0065] 6. Since the pool type of the present invention is compact and flexible in design, it can be operated in parallel or in series, adapting to a wide range of water volume and water quality, and is combined with a sedimentation tank with a compact structure, thereby saving space and investment.

[0066] 7. Since the internal circulation of the nitrification liquid of the present invention does not require a water pump, it is completed by a reasonable pool layout, plug flow, and air stripping equipment, thereby improving the denitrification efficiency while also reducing energy consumption and saving operating costs.

[0067] 8. Since the aeration device of the present invention adopts an integrally liftable modular device, it is easy to install and flexible to adjust. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic diagram of the MCC multiple selection combined sewage treatment process tank type and layout of a specific embodiment of the present invention;

[0069] Figure 2 It is a general mode arrangement and flow pattern schematic diagram of a specific embodiment of the present invention;

[0070] Figure 3 It is a schematic diagram of the efficient mode arrangement and flow pattern of a specific embodiment of the present invention;

[0071] Figure 4 It is a schematic diagram of the enhanced mode arrangement and flow pattern of a specific embodiment of the present invention;

[0072] Figure 5 Based Figure 1 A schematic cross-sectional view of the combined area G in the 1-1 direction;

[0073] Figure 6It is a schematic structural diagram of an integral lifting aeration device according to a specific embodiment of the present invention.

[0074] Wherein: 1. First flow generator, 2. Second flow generator, 3. Third flow generator, 4. First air stripping device, 5. Second air stripping device, 6. Third air stripping device, 7. Fourth air stripping device, 8. Fifth air stripping device, 9. Overall lifting aeration device, 10. Adjusting weir gate, 11. Combination zone filler, 12. Top water outlet trough, 13. Perforated mud discharge pipe, 14. Adjusting valve, 15. Limiting guide rod, 16. Bronchi, A. First selection zone, B. Second selection zone, C. Third selection zone, D. Fourth selection zone, E. Fifth selection zone, F. Sixth selection zone, G. Combination zone, 0. Water inlet level, H. Water flow direction DETAILED DESCRIPTION

[0075] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0076] like Figure 1 As shown, the MCC multiple selection combined sewage treatment system and method include a first selection area A, a second selection area B, a third selection area C, a fourth selection area D, a fifth selection area E, a sixth selection area F, and a combined area G, wherein: the combined area G is located in the center of the sewage treatment system; the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F are respectively adjacent to the combined area G, and are arranged in sequence in a clockwise direction around the combined area G; the inlet water is controlled by a valve and enters the first selection area A or the second selection area B.

[0077] The first selection area A is provided with a first flow producer 1, a second flow producer 2, a first air lift device 4, a second air lift device 5 and an adjusting weir gate 10 for controlling the water flow direction and the backflow amount; the first flow producer 1, the first air lift device 4 and the adjusting weir gate 10 are arranged on the adjacent sides of the first selection area A and the second selection area B; the second flow producer 2 and the second air lift device 5 are arranged on the adjacent sides of the first selection area A and the sixth selection area F.

[0078] A third gas lift device 6 is provided inside the third selection zone C and on the adjacent side of the fourth selection zone D; a fourth gas lift device 7 is provided inside the fourth selection zone D and on the adjacent side of the fifth selection zone E; a fifth gas lift device 8 is provided inside the fifth selection zone E and on the adjacent side of the fourth selection zone D; a third flow promoter 3 is provided on the adjacent side of the fourth selection zone D and the combination zone G.

[0079] Aeration device interfaces for installing the integral lifting aeration device 9 are respectively provided in the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F.

[0080] The bottoms of the second selection area B and the third selection area C are provided with perforated mud discharge pipes 13 .

[0081] It should be noted that the total gas consumption of the first gas stripping device 4, the second gas stripping device 5, the third gas stripping device 6, the fourth gas stripping device 7 and the fifth gas stripping device 8 accounts for 5%-10% of the total gas consumption.

[0082] It should be noted that the first flowmaker 1 , the second flowmaker 2 , and the third flowmaker 3 can adjust their directions so as to control the direction of water flow.

[0083] It should be further explained that the process does not require an internal reflux pump. The internal reflux is achieved through the bottom of the sedimentation zone and the overall flow pattern. The reflux ratio has a wide adjustment range of 2:1 to 20:1. When only the flowmaker is turned on, a reflux rate of 2:1 to 3:1 can be achieved. When the flowmaker and the gas stripping device are combined, a reflux rate of 10:1 to 20:1 can be achieved.

[0084] like Figure 6 As shown, it should be noted that the adjustment of the local aeration volume of the integral lifting aeration device 9 is adjusted by adjusting the valve 14 or moving the position of the integral lifting aeration device 9; the adjustment range of dissolved oxygen in the aeration zone is 0.3mg / l to 2mg / l; the integral lifting aeration device 9 is reserved with a bronchial tube 16 and a limit guide rod 15, and the position is adjusted according to actual needs. The bronchial tube 16 is provided with an adjusting valve 14, which can adjust the opening size and opening and closing to achieve the adjustment of the air volume.

[0085] It should be noted that a precipitator is provided inside the combination area G; the bottom of the combination area G is connected to the first selection area A and the fourth selection area D respectively.

[0086] It should be further explained that the combined area G is a rapid clarification area. After the separation of mud and water, part of the sludge is sucked back to the aeration area from the bottom of the sedimentation tank through the lifting pump. The remaining sludge is partially returned to the front end of the system through the sludge pump, and the other part is discharged to the sludge storage tank. The mixed liquid is returned to the front end for denitrification and denitrification; the clear water in the rapid clarification area is collected by the upper water collection tank and then discharged. Therefore, this process does not require a separate secondary sedimentation tank, saving land and investment.

[0087] like Figure 5As shown, in this specific embodiment, the effective water depth of the biological pool of the combination area G is 6 meters; a combination area filler 11 is provided in the combination area G; the bottom of the combination area filler 11 is 2 meters away from the bottom of the pool, the top is 1.5 meters away from the liquid surface, and the filler layer height is 2.5 meters; the combination area filler 11 is a labyrinth-type filler; the effluent is collected through the top outlet trough 12 of the combination area G and then aggregated to the outlet channel and then discharged to the subsequent units.

[0088] In this specific embodiment, the residence time of sewage in each block of the sewage treatment system is adjusted according to the difference in influent water quality; when treating conventional sewage, the residence time of sewage in the first selection area A is 3 hours, the residence time in the second selection area B and the sixth selection area F is 2 hours respectively, the residence time in the third selection area C and the fifth selection area E is 8 hours respectively, and the residence time in the fourth selection area D is 1 hour. The total residence time of sewage in the system is 16 hours; the surface load range of the combined area G is 1m 3 / m 2 ·h~1.2m 3 / m 2 ·h.

[0089] The sewage treatment method utilizing the MCC multiple selection combined sewage treatment system includes a general mode, a high-efficiency mode and an enhanced mode; when the system water inlet index reaches the manually preset general mode activation condition, the general mode is activated; when the system water inlet index reaches the manually preset high-efficiency mode activation condition, the high-efficiency mode is activated; when the system water inlet index reaches the manually preset enhanced mode activation condition, the enhanced mode is activated.

[0090] like Figure 2 As shown, it should be noted that the general mode includes the following steps:

[0091] Sa1. Install the integral lifting aeration device 9 onto the aeration device interfaces of the third selection zone C and the fifth selection zone E.

[0092] Sa2. The mixed liquid enters the first selection area A until the water inflow reaches the manually preset target water inflow.

[0093] Sa3. Adjust the weir gate 10 to fully open, start the first flowmaker 1 and the second flowmaker 2 to push the mixed liquid into the second selection area B and the sixth selection area F respectively, until the water volume in the second selection area B and the sixth selection area F reaches half of the target water inflow volume respectively.

[0094] Sa4. Control the sludge concentration, mixed liquor reflux ratio, and gas-water ratio of the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F to achieve general mode control parameters.

[0095] Sa5. Control the dissolved oxygen in the second selection zone B and the sixth selection zone F to reach the artificially preset anaerobic conditions.

[0096] Sa6. Control the first selection area A and the fourth selection area D to achieve artificially preset hypoxic conditions.

[0097] Sa7. Turn on the integral lifting aeration device 9 of the third selection zone C and the fifth selection zone E until the dissolved oxygen in the third selection zone C and the fifth selection zone E reaches the manually preset aerobic condition.

[0098] Sa8. With the first selection area A, the second selection area B, and the third selection area C as the first group, and the first selection area A, the sixth selection area F, and the fifth selection area E as the second group, the system forms two sets of parallel inverted AAO processes.

[0099] Sa9. The mixed liquid flows back to the combination area G for mud and water separation.

[0100] It should be further explained that in step Sa6, the mixed solution flows back to the first selection area A and the fourth selection area D, bringing in some dissolved oxygen, so that the dissolved oxygen concentration in the area reaches 0.2 mg / l to 0.5 mg / l, achieving anoxic conditions.

[0101] It should be further explained that, in the general mode, the first selection area A is anoxic area, the second selection area B, the sixth selection area F, the third selection area C, and the fifth selection area E are aerobic areas, the fourth selection area D is a water distribution area, and the combination area G is anoxic + precipitation area combination area. In this way, two groups of AAO mode processes are formed. This mode is mature and stable for treating conventional design influent.

[0102] In general mode, the two groups can run simultaneously, or only one of them can be run, so the water volume adjustment range is large.

[0103] It should be further explained that the general mode is two sets of parallel inverted AAO processes. The process is mature and stable, and the parallel operation makes the system operation mode more flexible. When the water volume is low, the single set operation can be controlled by adjusting the weir gate 10 to save energy. When the water volume is too high, it can be operated in high-efficiency mode or enhanced mode.

[0104] In this specific embodiment, in the general mode, when the total water inflow reaches half of the target water inflow, the regulating weir gate 10 can be closed and the system can be operated unilaterally to reduce operating costs. When the total water inflow is within the range of 1.1 to 1.4 times the target water inflow and the water quality is general, it can be operated in the high-efficiency mode or the multi-stage AO mode in the enhanced mode.

[0105] like Figure 3 As shown, it should be noted that the high-efficiency mode includes the following steps:

[0106] Sb1. Install the integral lifting aeration device 9 to the aeration device interfaces of the second selection area B, the third selection area C, the fifth selection area E, and the sixth selection area F.

[0107] Sb2. The mixed liquid enters the first selection area A until the water inflow reaches the manually preset target water inflow.

[0108] Sb3. Start the first flowmaker 1 and the second flowmaker 2 to push the mixed liquid into the second selection area B and the sixth selection area F respectively.

[0109] Sb4. Control the sludge concentration, mixed liquor reflow ratio, and gas-water ratio of the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F to achieve high-efficiency mode control parameters.

[0110] Sb5. When the mixed liquor reflux ratio reaches 10:1, the first gas stripping device 4 and the second gas stripping device 5 are opened; when the mixed liquor reflux ratio reaches 20:1, the third gas stripping device 6 and the fifth gas stripping device 8 are opened.

[0111] Sb6. The first selection zone A is not aerated until the artificially preset anaerobic conditions are reached.

[0112] Sb7. Control the overall lifting aeration device 9 of the second selection area B, the third selection area C, the fifth selection area E, and the sixth selection area F to achieve the manually preset facultative oxygen conditions.

[0113] Sb8. The fourth selection area D is set as the water distribution area, and the third flow generator 3 is turned on to push the mixed liquid to the combination area G.

[0114] It should be further explained that, in the high-efficiency mode, the first selection zone A is an anaerobic zone, the second selection zone B, the third selection zone C, the fifth selection zone E, and the sixth selection zone F are facultative anoxic zones, the fourth selection zone D is a water distribution zone, the bottom layer of the combined zone G is an anoxic zone, and the upper layer is a sedimentation zone. In this way, two groups of high-efficiency treatment units are formed, and synchronous nitrification and denitrification biological reactions are carried out in a low-oxygen environment and high sludge concentration. When the influent TN is high, the effluent can be guaranteed to meet the standards. In the high-efficiency mode, the sludge concentration in the aeration zone is high, and it is easy to form a large bacterial floc. The oxygen supply inside the bacterial floc is distributed in a gradient. Denitrification reaction occurs inside the bacterial floc, that is, the granular sludge. Most of the nitrite participates in the reaction, which is a short-range nitrification, that is, this mode provides adaptive conditions for synchronous nitrification and denitrification.

[0115] It should be further explained that the low dissolved oxygen in the aeration zone under the high-efficiency mode makes the nitrification reaction take the leading position when the NH3-H+ in the sewage undergoes nitrification reaction; at the same time, due to the limited supply of oxygen, the oxygen supply inside the sludge flocs is distributed in a gradient, and the denitrification reaction occurs inside the flocs, that is, the granular sludge, and most of the nitrite participates in the reaction, achieving short-range nitrification and greatly reducing the consumption of carbon sources in the denitrification process. Under high sludge concentration, tiny bubbles are enriched around the sludge flocs, and the dissolved oxygen gradually decreases from the outside to the inside. The flocs form aerobic zones, anoxic zones, and anaerobic zones from the outside to the inside. Under the action of microorganisms, biological denitrification is completed in the aerobic zone and the anoxic zone, and biological phosphorus removal is completed in the anaerobic zone. On the outer surface of the sludge flocs, the dissolved oxygen concentration is relatively high, equal to the dissolved oxygen concentration of the mixed liquid in the reactor; the outer surface is mainly composed of aerobic bacteria and nitrifying bacteria, where nitrification occurs. When entering the sludge bacterial flocs, oxygen transfer is blocked, and due to the large amount of oxygen consumed outside the sludge bacterial flocs, anoxic zones are generated in the sludge bacterial flocs, where denitrifying bacteria are dominant and denitrification reactions are carried out. Therefore, a large number of bacterial flocs in the aeration zone form a large number of aerobic zones, anoxic zones, and anaerobic environments, completing the biological denitrification and phosphorus removal reactions. Synchronous nitrification and denitrification can be achieved in one tank.

[0116] The reaction equation is expressed as formula 1 and formula 2:

[0117] NH4 + +1.5O2→NO2 - +2H + +H2O (1)

[0118] NO2 - +3H (organic electron donor) → 1 / 2N2 + H2O + OH - (2)

[0119] It should be further explained that the generation cycle of nitrite bacteria is short, and the sludge age is also short. Controlling it in the nitrite stage can increase the concentration of microorganisms and the speed of nitrification reaction, shorten the nitrification reaction time, thereby reducing the reactor volume and saving infrastructure investment. On the other hand, it reduces the contradiction in the sludge age control of denitrification and phosphorus removal. From the biological oxidation reaction of nitrite bacteria, it can be seen that controlling it in the nitrite stage can save the oxygen consumption of nitrite nitrogen to nitrate nitrogen. In addition, from the perspective of denitrification, less hydrogen donors are required to reduce nitrite to nitrogen.

[0120] like Figure 4 As shown, it should be noted that the enhanced mode includes the following steps:

[0121] Sc1. Install the integral lifting aeration device 9 to the aeration device interfaces of the first selection area A, the third selection area C, and the fifth selection area E.

[0122] Sc2. The mixed liquid enters the second selection area B until the water inflow reaches the manually preset target water inflow.

[0123] Sc3. Close the regulating weir gate 10 and the first flowmaker 1 to allow the mixed liquid to flow through the third selection area C.

[0124] The second selection zone B and the third selection zone C are not aerated. When the second selection zone B and the third selection zone C reach anaerobic conditions, a hydrolysis reaction occurs to convert the difficult-to-biodegrade macromolecules into easily biodegradable small molecules, which is beneficial to subsequent unit treatment. The hydrolyzed sludge is discharged through the perforated sludge discharge pipe 13.

[0125] The third selection zone C is aerated by the integral lifting aeration device 9 until the third selection zone C reaches aerobic conditions to condition the high-concentration wastewater.

[0126] When treating special wastewater, the third selection area C is used to pre-treat the sewage by placing fillers, carriers, and bacteria to meet the discharge requirements of subsequent biochemical and deep treatment.

[0127] Sc4. Control the sludge concentration, mixed liquor reflow ratio, and gas-water ratio of the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F to achieve the enhanced mode control parameters.

[0128] Sc5. The mixed liquid flows through the fourth selection area D, the fifth selection area E, the sixth selection area F, and the first selection area A in sequence; the fourth selection area D and the sixth selection area F are controlled to reach anoxic conditions.

[0129] Sc.6 The mixed liquor enters the combination zone G; the clean water in the combination zone G flows out from the overflow tank above, and the mixed liquor and sludge flow back to the fourth selection zone D.

[0130] It should be further explained that in step Sc6, the reflux is controlled by controlling the agitator in the corresponding area to propel it along the forward direction of the water flow.

[0131] It should be further explained that in the enhanced mode, the second selection zone B is an anaerobic zone; the third selection zone C can be an aerobic zone or an anaerobic zone according to water quality conditions; the first selection zone A and the fifth selection zone E are aerobic zones; the fourth selection zone D and the sixth selection zone F are anoxic zones; and the combined zone G is a sedimentation zone. In this way, a three-level AO is formed, or hydrolysis + AO + AO, in which the first-level AO mainly plays a role in regulation and modification, and the second and third levels are enhanced process sections, which mainly treat sewage that is difficult to degrade and has excessive COD in the influent.

[0132] It should be further explained that in the enhanced mode, the valves of the perforated mud discharge pipes 13 at the bottom of the second selection area B and the third selection area C are opened to discharge mud.

[0133] It should be further explained that the enhanced mode is effective in removing COD, and is particularly effective in treating difficult-to-degrade organic matter than conventional processes.

[0134] In this specific embodiment, the general mode activation conditions are: inlet COD≤300mg / l, TN≤30mg / l, B / C≥0.3; the high efficiency mode activation conditions are: inlet 300mg / l<COD≤400mg / l, 30mg / l<TN≤60mg / l, B / C≥0.3.

[0135] The conditions for enabling the enhanced mode are: the critical design conditions of the system are met and B / C is less than 0.3.

[0136] The general mode control parameters are: the sludge concentration range of the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F is 3000mg / l~4000mg / l; the mixed liquor reflux ratio range is 2:1~3:1; the gas-water ratio range is 6:1~8:1.

[0137] The control parameters of the high-efficiency mode are: the sludge concentration range of the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F is 6g / l~8g / l; the mixed liquor reflux ratio range is 10:1~20:1; the gas-water ratio range is 4:1~6:1.

[0138] The control parameters of the enhanced mode are: the sludge concentration of the first selection area A, the second selection area B, the third selection area C, the fourth selection area D, the fifth selection area E, and the sixth selection area F is in the range of 3g / l to 4g / l; the mixed liquor reflux ratio is 3:1. The gas-water ratio ranges from 6:1 to 10:1.

[0139] The specific condition of anaerobic condition is that the dissolved oxygen is less than 0.2 mg / l.

[0140] The specific condition of the anoxic condition is that the dissolved oxygen ranges from 0.2 mg / l to 0.5 mg / l.

[0141] The specific condition of aerobic condition is that the dissolved oxygen reaches 2 mg / l.

[0142] The specific condition of the anaerobic condition is that the dissolved oxygen range is 0.3 mg / l to 1 mg / l.

[0143] It should be noted that the sludge concentration is controlled by controlling the mixed liquor reflux ratio and the discharge of the remaining sludge; the mixed liquor reflux ratio is controlled by the flow promoter and the air lift device; the discharge of the remaining sludge is controlled by the sludge pump; the gas-water ratio is achieved by adjusting the air volume of the blower installed in the corresponding area.

[0144] It should be further explained that the switching methods of different modes are as follows:

[0145] The main difference between the general mode and enhanced mode is the flow state, while the sludge concentration and the characteristics of the running sludge bacteria are similar, so they can be switched quickly.

[0146] When other modes are switched to high-efficiency mode, the sludge return ratio needs to be increased according to the above method, the sludge concentration in the aeration zone needs to be adjusted to gradually rise to 6-8g / l, and the air volume of the blower needs to be adjusted to control the dissolved oxygen at 0.3mg / l~1mg / l. The flow pattern is implemented according to the above scheme. After a period of stable operation, a large number of bacterial flocs in the aeration zone form a large number of aerobic zones, anoxic zones, and anaerobic environments, completing the biological denitrification and phosphorus removal reactions. Synchronous nitrification and denitrification can be achieved in the tank body.

[0147] When the high efficiency mode is switched to other modes, the air stripping device is turned off to reduce the mixed liquor return flow, thereby reducing the sludge concentration to the sludge concentration of the required mode, and the dissolved oxygen concentration in the aeration tank is increased by increasing the aeration volume. The flow pattern change is controlled by the direction of the agitator.

[0148] It should be further explained that when the inlet water concentration is low, the enhanced mode and high-efficiency mode can treat more sewage and meet the treatment requirements when the water volume changes greatly.

[0149] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0150] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0151] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0152] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An MCC multiple selection combined sewage treatment system, characterized by: The system comprises a first selection area (A), a second selection area (B), a third selection area (C), a fourth selection area (D), a fifth selection area (E), a sixth selection area (F), and a combination area (G), wherein: the combination area (G) is arranged in the center of the sewage treatment system; the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) are respectively adjacent to the combination area (G), and are arranged in sequence in a clockwise direction around the combination area (G); the inlet water is controlled by a valve to enter the first selection area (A) or the second selection area (B); The first selection area (A) is provided with a first flow producer (1), a second flow producer (2), a first air stripping device (4), a second air stripping device (5) and an adjusting weir gate (10) for controlling the water flow direction and the amount of backflow; the first flow producer (1), the first air stripping device (4) and the adjusting weir gate (10) are arranged on the adjacent sides of the first selection area (A) and the second selection area (B); the second flow producer (2) and the second air stripping device (5) are arranged on the adjacent sides of the first selection area (A) and the sixth selection area (F); A third gas stripping device (6) is provided inside the third selection zone (C) and on the adjacent side of the fourth selection zone (D); a fourth gas stripping device (7) is provided inside the fourth selection zone (D) and on the adjacent side of the fifth selection zone (E); a fifth gas stripping device (8) is provided inside the fifth selection zone (E) and on the adjacent side of the fourth selection zone (D); a third flow promoter (3) is provided on the adjacent side of the fourth selection zone (D) and the combination zone (G); Aeration device interfaces for installing an integral lifting aeration device (9) are respectively provided in the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F); The bottoms of the second selection area (B) and the third selection area (C) are provided with perforated mud discharge pipes (13).

2. The MCC multiple selection combined sewage treatment system according to claim 1 is characterized in that: The total gas consumption of the first gas stripping device (4), the second gas stripping device (5), the third gas stripping device (6), the fourth gas stripping device (7) and the fifth gas stripping device (8) accounts for 5%-10% of the total gas consumption.

3. The MCC multiple selection combined sewage treatment system according to claim 2 is characterized in that: The residence time of sewage in each block of the sewage treatment system is adjusted according to the difference in influent water quality; when treating conventional sewage, the residence time of sewage in the first selection area (A) is 3 hours, the residence time in the second selection area (B) and the sixth selection area (F) is 2 hours respectively, the residence time in the third selection area (C) and the fifth selection area (E) is 8 hours respectively, and the residence time in the fourth selection area (D) is 1 hour. The total residence time of sewage in the system is 16 hours; the surface load range of the combined area (G) is 1m 3 / m 2 ·h~1.2m 3 / m 2 ·h.

4. The MCC multiple selection combined sewage treatment system according to claim 3 is characterized by: The local aeration volume of the integral lifting aeration device (9) is adjusted by adjusting the valve (14) or moving the position of the integral lifting aeration device (9); the adjustment range of dissolved oxygen in the aeration zone is 0.3 mg / l to 2 mg / l; the integral lifting aeration device (9) is reserved with a bronchial tube (16) and a limiting guide rod (15), and the position is adjusted according to actual needs. The bronchial tube (16) is provided with the regulating valve (14).

5. The MCC multiple selection combined sewage treatment system according to claim 4 is characterized in that: A precipitator is provided inside the combination zone (G); the bottom of the combination zone (G) is connected to the first selection zone (A) and the fourth selection zone (D) respectively; The effective water depth of the biological pool of the combination zone (G) is 6 meters; a combination zone filler (11) is provided in the combination zone (G); the bottom of the combination zone filler (11) is 2 meters away from the pool bottom, the top is 1.5 meters away from the liquid surface, and the filler layer height is 2.5 meters; the combination zone filler (11) is a labyrinth-type filler; the effluent is collected through the top outlet trough (12) of the combination zone (G) and then collected in the outlet channel and then discharged to the subsequent unit.

6. A sewage treatment method using the MCC multiple selection combined sewage treatment system according to claim 5, characterized in that: It includes general mode, high-efficiency mode and enhanced mode; when the water inflow index of the system reaches the general mode activation condition preset manually, the general mode is activated; When the water inlet index of the system reaches the manually preset high-efficiency mode activation condition, the high-efficiency mode is activated; When the water inflow index of the system reaches the manually preset enhancement mode activation condition, the enhancement mode is activated.

7. The sewage treatment method according to claim 6, characterized in that: The general pattern comprises the following steps: Sa1. The overall lifting aeration device (9) is installed on the aeration device interface of the third selection zone (C) and the fifth selection zone (E); Sa2 mixed liquid from the first selection area (A) water, until the water volume reaches the manually preset target water volume; Sa3. The regulating weir gate (10) is fully opened, and the first flow generator (1) and the second flow generator (2) are started to push the mixed liquid into the second selection area (B) and the sixth selection area (F) respectively, until the water volume of the second selection area (B) and the sixth selection area (F) reaches half of the target water inflow volume; Sa4. Control the sludge concentration, mixed liquor reflux ratio, and gas-water ratio of the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) to achieve the general mode control parameters; Sa5. Controlling the dissolved oxygen in the second selection zone (B) and the sixth selection zone (F) to achieve artificially preset anaerobic conditions; Sa6. Controlling the first selection area (A) and the fourth selection area (D) to achieve artificially preset hypoxic conditions; Sa7. Open the integral lifting aeration device (9) of the third selection zone (C) and the fifth selection zone (E) until the dissolved oxygen in the third selection zone (C) and the fifth selection zone (E) reaches the manually preset aerobic conditions; Sa8. The first selection area (A), the second selection area (B), and the third selection area (C) are the first group, and the first selection area (A), the sixth selection area (F), and the fifth selection area (E) are the second group, and the system forms two sets of parallel inverted AAO processes; Sa9. The mixed liquid flows back to the combination zone (G) for mud and water separation.

8. The sewage treatment method according to claim 7, characterized in that: The high efficiency mode comprises the following steps: Sb1. Installing the integral lifting aeration device (9) to the aeration device interface of the second selection area (B), the third selection area (C), the fifth selection area (E), and the sixth selection area (F); Sb2. The mixed liquid is fed into the first selection zone (A) until the water inflow reaches the manually preset target water inflow; Sb3. Start the first flow booster (1) and the second flow booster (2) to push the mixed solution into the second selection zone (B) and the sixth selection zone (F), respectively; Sb4. Control the sludge concentration, the mixed liquor recirculation ratio, and the gas-water ratio of the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) to achieve high-efficiency mode control parameters; Sb5. When the mixed liquor reflux ratio reaches 10:1, the first gas stripping device (4) and the second gas stripping device (5) are opened; when the mixed liquor reflux ratio reaches 20:1, the third gas stripping device (6) and the fifth gas stripping device (8) are opened; Sb6. The first selection zone (A) is not aerated until the artificially preset anaerobic conditions are reached; Sb7. Control the overall lifting aeration device (9) of the second selection zone (B), the third selection zone (C), the fifth selection zone (E), and the sixth selection zone (F) to achieve artificially preset facultative oxygen conditions; Sb8. The fourth selection zone (D) is set as a water distribution zone, and the third flow pusher (3) is turned on to push the mixed liquid to the combination zone (G).

9. The sewage treatment method according to claim 8, characterized in that: The enhanced mode comprises the following steps: Sc1. Installing the integral lifting aeration device (9) to the aeration device interface of the first selection area (A), the third selection area (C), and the fifth selection area (E); Sc2. The mixed liquid enters the second selection area (B) until the water inflow reaches the manually preset target water inflow; Sc3. Close the regulating weir (10) and the first flow generator (1), so that the mixed liquid flows through the third selection zone (C); The second selection zone (B) and the third selection zone (C) are not aerated. When the second selection zone (B) and the third selection zone (C) reach the anaerobic condition, a hydrolysis reaction occurs to convert the macromolecular substances that are difficult to biodegrade into small molecular substances that are easy to biodegrade, which is beneficial to subsequent unit treatment. The hydrolyzed sludge is discharged through the perforated sludge discharge pipe (13); The integral lifting aeration device (9) of the third selection zone (C) is aerated until the third selection zone (C) reaches the aerobic condition to condition the high-concentration wastewater; When treating special wastewater, the third selection area (C) is used to pre-treat the wastewater by placing fillers, carriers, and bacteria; Sc4. Control the sludge concentration, the mixed liquor recirculation ratio, and the gas-water ratio of the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) to achieve the enhanced mode control parameters; Sc5. The mixed solution flows through the fourth selection area (D), the fifth selection area (E), the sixth selection area (F), and the first selection area (A) in sequence; the fourth selection area (D) and the sixth selection area (F) are controlled to reach the anoxic condition; Sc.6 The mixed liquor enters the combination zone (G); the clean water in the combination zone (G) flows out from the overflow trough above, and the mixed liquor and sludge flow back to the fourth selection zone (D).

10. The sewage treatment method according to claim 9, characterized in that: The general mode activation conditions are: influent COD ≤ 300 mg / l, TN ≤ 30 mg / l, B / C ≥ 0.3; The high efficiency mode activation conditions are: influent 300mg / l<COD≤400mg / l, 30mg / l<TN≤60mg / l, B / C≥0.3; The enhancement mode activation condition is: the critical design condition of the system is reached and B / C is less than 0.

3. The general mode control parameters are: the sludge concentration of the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) is in the range of 3000 mg / l to 4000 mg / l; the mixed liquor reflux ratio is in the range of 2:1 to 3:1; the gas-water ratio is in the range of 6:1 to 8:1; The high-efficiency mode control parameters are: the sludge concentration of the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) is in the range of 6 g / l to 8 g / l; the mixed liquor reflux ratio is in the range of 10:1 to 20:1; the gas-water ratio is in the range of 4:1 to 6:1; The control parameters of the enhanced mode are: the sludge concentration of the first selection area (A), the second selection area (B), the third selection area (C), the fourth selection area (D), the fifth selection area (E), and the sixth selection area (F) is in the range of 3g / l to 4g / l; the mixed liquor reflux ratio is 3:

1. The gas-water ratio is in the range of 6:1 to 10:1; The specific condition of the anaerobic condition is that the dissolved oxygen is less than 0.2 mg / l; The specific condition of the anoxic condition is that the range of dissolved oxygen is 0.2mg / l-0.5mg / l; The specific condition of the aerobic condition is that the dissolved oxygen reaches 2 mg / l; The specific condition of the anaerobic condition is that the range of the dissolved oxygen is 0.3 mg / l to 1 mg / l.

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