Integrated biochemical reaction apparatus and wastewater treatment method

Abstract

The present application relates to sewage treatment technical field, provide a kind of integrated biochemical reaction equipment and sewage treatment method.Integrated biochemical reaction equipment includes primary anoxic zone, primary aerobic zone, secondary anoxic zone, secondary aerobic zone and three-phase separator.The first end of primary aerobic zone is communicated with the end of primary anoxic zone, and the end of primary aerobic zone is communicated with the first end of primary anoxic zone;The first end of secondary anoxic zone is communicated with the end of primary aerobic zone;The first end of secondary aerobic zone is communicated with the end of secondary anoxic zone, and the end of secondary aerobic zone is communicated with the first end of primary aerobic zone;Three-phase separator includes water inlet channel, sludge-water separation bin and sludge-water outlet, and the first end of water inlet channel is communicated with secondary aerobic zone, and the first end of secondary aerobic zone is communicated with sludge-water outlet.The present application is used to solve the defect that the total nitrogen removal rate cannot be proportionally improved by increasing reflux ratio in the existing Bardenpho prototype process, thereby leading to poor economy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and in particular to an integrated biochemical reaction device and a sewage treatment method. BACKGROUND

[0002] In the existing sewage treatment process, it is generally believed that the total Kjeldahl nitrogen removal rate of the primary ANO denitrification process is difficult to reach 90%, therefore, in order to achieve a higher total Kjeldahl nitrogen removal rate or obtain lower total nitrogen effluent, the two-stage AO Bardenpho biochemical process scheme is usually selected to achieve a total Kjeldahl nitrogen removal rate of more than 90% or obtain lower total nitrogen effluent (such as 10 mg / L or less).

[0003] In the prototype process of Bardenpho, the mixed liquid reflux ratio of the primary aerobic zone to the primary anoxic zone is generally controlled at about 400%, so it is generally believed that the total nitrogen removal rate of the primary nitrification and denitrification is about 70%, and the remaining total nitrogen is removed by denitrification in the secondary anoxic zone, which limits the total nitrogen removal rate to a certain extent. The reason is that, on the one hand, the primary mixed liquid reflux is usually mechanical reflux, and increasing the reflux ratio will lead to an increase in reflux energy consumption that is not proportional to the economic efficiency of the primary total nitrogen removal rate; on the other hand, increasing the reflux ratio will cause more dissolved oxygen to be refluxed to the primary anoxic zone, which will consume more carbon sources in the raw water, which is not economical.

[0004] Therefore, there is an urgent need for an integrated biochemical reaction device and a sewage treatment method to solve the above problems. SUMMARY

[0005] The present application provides an integrated biochemical reaction device and a sewage treatment method to solve the problem that in the existing prototype process of Bardenpho, increasing the reflux ratio cannot proportionally improve the total nitrogen removal rate, thereby resulting in poor economic efficiency.

[0006] In one aspect, the present application provides an integrated biochemical reaction device, comprising: a primary anoxic zone, a primary aerobic zone, a secondary anoxic zone, a secondary aerobic zone, and a three-phase separator.

[0007] The first end of the primary anoxic zone is provided with a water inlet pipe for sewage; the first end of the primary aerobic zone is communicated with the last end of the primary anoxic zone, and the last end of the primary aerobic zone is communicated with the first end of the primary anoxic zone; the first end of the secondary anoxic zone is communicated with the last end of the primary aerobic zone; the first end of the secondary aerobic zone is communicated with the last end of the secondary anoxic zone, and the last end of the secondary aerobic zone is communicated with the first end of the primary aerobic zone; the three-phase separator comprises a water inlet channel, a sludge-water separation bin, a sludge-water outlet and a clear water outlet, the first end of the water inlet channel is communicated with the secondary aerobic zone, the last end of the water inlet channel is communicated with the sludge-water separation bin and the sludge-water outlet, the sludge-water outlet is communicated with the sludge-water separation bin, the first end of the secondary aerobic zone is communicated with the sludge-water outlet, and the clear water outlet is arranged at the top of the sludge-water separation bin.

[0008] According to the integrated biochemical reaction equipment, the three-phase separator comprises first, second and third partitions arranged at intervals, and the secondary anoxic zone and the secondary aerobic zone are arranged on the two sides of the first partition respectively; the sludge-water separation bin is formed between the first partition and the second partition, the water inlet channel is formed between the second partition and the third partition, a sludge-water inlet is arranged between the first partition and the second partition, the sludge-water inlet is communicated with the sludge-water separation bin, and the sludge-water outlet is arranged between the first partition and the third partition.

[0009] According to the integrated biochemical reaction equipment, the last end of the primary aerobic zone is communicated with the first end of the primary anoxic zone through a first dynamic backflow channel; and / or, the last end of the primary aerobic zone is communicated with the first end of the primary anoxic zone through a water passing hole.

[0010] According to the integrated biochemical reaction equipment, the last end of the secondary aerobic zone is communicated with the first end of the primary aerobic zone through a flow passing hole; and / or, the last end of the secondary aerobic zone is communicated with the first end of the primary aerobic zone through a second dynamic backflow channel.

[0011] According to the integrated biochemical reaction equipment, at least one of the primary anoxic zone, the primary aerobic zone and the secondary anoxic zone is internally provided with a guide plate for increasing a sewage flow path.

[0012] According to the integrated biochemical reaction equipment, the primary aerobic zone is arranged at the periphery of the primary anoxic zone, and the outer wall of the primary anoxic zone forms a guide plate for increasing a sewage flow path.

[0013] According to the integrated biochemical reaction equipment, the primary anoxic zone, the primary aerobic zone, the secondary anoxic zone and the secondary aerobic zone are all internally provided with fixed type composite biological fillers and / or suspended type MBBR biological fillers.

[0014] Another aspect of the present application provides a wastewater treatment method based on the integrated biochemical reaction device according to any one of the above, comprising the following steps.

[0015] The wastewater is introduced into the first anoxic zone, and carbon source in the wastewater is mixed with the first nitrification sludge mixture returned from the end of the first aerobic zone into the first anoxic zone to occur denitrification reaction, to obtain the first denitrification sludge mixture.

[0016] The first denitrification sludge mixture is introduced into the first aerobic zone to occur aerobic decarburization and nitrification reaction under aerobic condition, to obtain the first nitrification sludge mixture.

[0017] Part of the first nitrification sludge mixture is returned into the first anoxic zone for circulation, and the other part of the first nitrification sludge mixture is introduced into the second anoxic zone to further occur denitrification reaction under the condition of carbon source, to obtain the second denitrification sludge mixture.

[0018] The second denitrification sludge mixture is introduced into the second aerobic zone to further occur decarburization and nitrification reaction under aerobic condition, to obtain the second aerobic sludge mixture.

[0019] Part of the second aerobic sludge mixture enters the three-phase separator to separate gas, liquid and solid, and the gas obtained after separation returns to the second aerobic zone for repeated use, the clear water is discharged from the biochemical system, and the sludge slides along the way into the second aerobic zone and is collected to the end of the second aerobic zone, and the other part of the second aerobic sludge mixture is returned to the first aerobic zone for circulation.

[0020] According to the wastewater treatment method provided by the present application, the dissolved oxygen at the end of the first aerobic zone is controlled to be less than or equal to 1.0 mg / L; and / or, the oxidation-reduction potential at the end of the first aerobic zone is controlled to be less than or equal to +100.0 mV; and / or, the sludge concentration at the end of the second aerobic zone is controlled to be between 3 g / L and 10 g / L.

[0021] According to the wastewater treatment method provided by the present application, the return ratio of the first aerobic zone returned to the first anoxic zone is controlled to be greater than or equal to 300%, and the return ratio of the second aerobic zone returned to the first aerobic zone is controlled to be less than or equal to 200%.

[0022] The integrated biochemical reaction equipment provided by the application adopts a three-phase separator instead of a traditional external secondary sedimentation tank, can realize an integrated pool type structure, makes the internal structure arrangement of the sewage treatment equipment more compact, is favorable for saving the occupied area. The integrated pool type structure is favorable for reducing the elevation setting in the process flow, and even does not need to have an obvious elevation difference design in each functional partition, is favorable for reducing the reflux energy consumption. The high-efficiency reflux method is adopted, and it is easy to realize a higher reflux ratio in the primary nitrification and denitrification reaction process, that is, it is easy to realize a reflux ratio of 400% of the traditional Bardenpho process under the condition of lower energy consumption. The high reflux ratio can further improve the total nitrogen removal rate of the primary nitrification and denitrification on one hand, thereby improving the denitrification effect of the whole flow; on the other hand, the high reflux ratio can effectively improve the impact resistance of the primary nitrification and denitrification zone. From the perspective of the circulating path of the activated sludge, the three-phase separator does not need to set an independent sludge reflux device to reflux the sludge separated from the external secondary sedimentation tank to the anoxic zone, and the three-phase separator can realize that the secondary aerobic sludge separated by the three-phase separator automatically falls along the path to the secondary aerobic zone, is collected to the end of the secondary aerobic zone, and then is refluxed to the primary aerobic zone together with the primary aerobic sludge mixture to participate in the biochemical reaction. The reflux method has the advantages that on one hand, the construction of the sludge reflux facility can be saved, and the investment can be saved; on the other hand, the influence of the high dissolved oxygen reflux of the secondary aerobic zone on the denitrification of the primary anoxic zone and the secondary anoxic zone does not need to be worried, even if the dissolved oxygen refluxed to the primary aerobic zone is higher, the dissolved oxygen can also be reused; in addition, the sludge reflux method is favorable for greatly improving the average sludge concentration of the whole reactor, and further saving the occupied area.

[0023] Other advantages, objects, and features of the present application will be better understood from the following specification taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0025] Figure 1 is a schematic diagram of one of the embodiments of the integrated biochemical reaction equipment provided by the present application.

[0026] Figure 2 is Figure 1 A-A sectional view in

[0027] Figure 3 is a schematic view of the second embodiment of the integrated biochemical reaction device provided by the present application.

[0028] Figure 4 is Figure 3 is a B-B sectional view in the middle.

[0029] Figure 5 is a schematic view of the third embodiment of the integrated biochemical reaction device provided by the present application.

[0030] Figure 6 is Figure 5 is a C-C sectional view in the middle.

[0031] Figure 7 is a flowchart of the sewage treatment method provided by the present application.

[0032] Reference signs:

[0033] 1, primary anoxic zone; 2, primary aerobic zone; 3, secondary anoxic zone; 4, secondary aerobic zone; 5, three-phase separator; 501, water inlet channel; 502, sludge-water separation bin; 503, sludge-water outlet; 504, clean water outlet; 505, water outlet pipe; 506, combined filler; 507, water collecting tank; 508, first partition; 509, second partition; 510, third partition; 511, sludge-water inlet; 6, water inlet pipe; 7, flow passage; 8, electric control cabinet; 9, disinfection device; 10, first power backflow passage; 11, second power backflow passage; 12, sludge discharge pipeline; 13, flow guide plate; 14, third power backflow passage; 15, fourth power backflow passage; 16, fifth power backflow passage; 17, sixth power backflow passage; 18, aeration blower. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0035] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0036] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0037] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0038] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0039] The following will be described in conjunction with Figures 1 to 7 The present application provides an integrated biochemical reaction device and a sewage treatment method.

[0040] It should be noted that the "head" described below specifically refers to the inflow end of sewage, and the "tail" described below specifically refers to the outflow end of sewage. For example, "the head of the first-stage aerobic zone 2 communicates with the tail of the first-stage anoxic zone 1" specifically refers to that the inflow end of the first-stage aerobic zone 2 communicates with the outflow end of the first-stage anoxic zone 1.

[0041] Referring to FIGS. 1 and 2, Figure 1 and Figure 2 It should be noted that the "head" described below specifically refers to the inflow end of sewage, and the "tail" described below specifically refers to the outflow end of sewage. For example, "the head of the first-stage aerobic zone 2 communicates with the tail of the first-stage anoxic zone 1" specifically refers to that the inflow end of the first-stage aerobic zone 2 communicates with the outflow end of the first-stage anoxic zone 1.

[0042] The integrated biochemical reaction equipment provided by the application adopts a three-phase separator 5 instead of a traditional external secondary sedimentation tank, can realize an integrated pool type structure, makes the internal structure arrangement of the sewage treatment equipment more compact, is favorable for saving the occupied area. Adopting the integrated pool type structure is favorable for reducing the elevation setting in the process flow, does not need to design obvious elevation difference in each functional partition, is favorable for reducing the reflux energy consumption. Adopting the high-efficiency reflux method, it is easy to realize higher reflux ratio of the primary nitrification and denitrification reaction process, that is, it is easy to realize the reflux ratio of the primary mixed liquid of the traditional Bardenpho process of 400%. The high reflux ratio can further improve the total nitrogen removal rate of the primary nitrification and denitrification on one hand, thereby improving the denitrification effect of the whole flow; on the other hand, the high reflux ratio can effectively improve the impact resistance of the primary nitrification and denitrification zone. From the circulation path of the activated sludge, the three-phase separator 5 does not need to set an independent sludge reflux device to reflux the sludge separated from the external secondary sedimentation tank to the anoxic zone, the three-phase separator 5 can realize that the secondary aerobic sludge separated by the three-phase separator 5 automatically falls back to the secondary aerobic zone 4 along the path, is collected to the end of the secondary aerobic zone 4, and then is refluxed to the primary aerobic zone 2 together with the secondary aerobic sludge mixed liquid to participate in the biochemical reaction. The reflux method has the advantages that on one hand, the construction of the sludge reflux facility can be saved, the investment is saved; on the other hand, the influence of the high dissolved oxygen reflux of the secondary aerobic zone 4 on the denitrification of the primary anoxic zone 1 and the secondary anoxic zone 3 does not need to be worried, even if the dissolved oxygen refluxed to the primary aerobic zone 2 is higher, the dissolved oxygen can also be reused; in addition, the sludge reflux method is also favorable for greatly improving the average sludge concentration of the whole reactor, further saving the occupied area.

[0043] Specifically, referring to FIG. 1, Figure 1 In the embodiment, the integrated biochemical reaction equipment includes a first reaction pool, a second reaction pool and a third reaction pool which are sequentially and adjacently arranged. The primary anoxic zone 1 is arranged in the first reaction pool, the primary aerobic zone 2 is arranged in the second reaction pool, and the three-phase separator 5 is arranged in the third reaction pool and is sealingly connected with the bottom end of the third reaction pool, so as to separate the third reaction pool into the secondary anoxic zone 3 and the secondary aerobic zone 4. The third reaction pool is provided with a device room on one side, and the device room is provided with an aeration fan 18, an electric control cabinet 8 and a disinfection device 9. The aeration fan 18 is used for providing an aeration source for the aeration device in the primary aerobic zone 2 and the secondary aerobic zone 4. The electric control cabinet 8 is used for controlling the control operation of the whole device. The disinfection device 9 is installed on the effluent pipe 505 and can be an ultraviolet disinfection device or a chemical disinfection device, so as to disinfect the clean water in the effluent pipe 505 and prevent the discharged clean water from polluting the environment.

[0044] The end of the first-stage anoxic zone 1 is communicated with the head of the first-stage aerobic zone 2 through a water passing hole, the end of the first-stage aerobic zone 2 is communicated with the head of the second-stage anoxic zone 3 through a flow passing channel 7, and the end of the second-stage anoxic zone 3 is communicated with the head of the second-stage aerobic zone 4 through a flow passing hole. The end of the first-stage aerobic zone 2 is communicated with the head of the first-stage anoxic zone 1 through a first power backflow channel 10, and the end of the second-stage aerobic zone 4 is communicated with the head of the first-stage aerobic zone 2 through a second power backflow channel 11. The backflow device provided by the first power backflow channel 10 and the second power backflow channel 11 is preferably a gas stripping backflow device, which can be a circular pipeline type gas stripping backflow device or a rectangular gas stripping backflow device.

[0045] The first-stage anoxic zone 1 and the second-stage anoxic zone 3 are provided with stirring devices for promoting the continuous contact between microorganisms and pollutants in the sewage and improving the efficiency of biochemical reactions. The stirring devices can be mechanical stirring devices or air stirring devices.

[0046] The sludge-water separation bin 502 of the three-phase separator 5 is provided with combined fillers 506 for sludge-water separation and a cleaning device for cleaning the combined fillers 506. The clean water outlet of the three-phase separator 5 is connected with a water collecting tank 507, and the water collecting tank 507 is communicated with a water outlet pipe 505. The bottom of the second-stage aerobic zone 4 is provided with a sludge discharge pipeline 12 for discharging sludge out of the equipment.

[0047] It should be noted that in the present embodiment, the number of the first-stage anoxic zone 1, the first-stage aerobic zone 2, the second-stage anoxic zone 3, the second-stage aerobic zone 4 and the three-phase separator 5 is at least one. When there are multiple first-stage anoxic zones 1, the multiple first-stage anoxic zones 1 can be communicated through water passing holes. When there are multiple first-stage aerobic zones 2, the multiple first-stage aerobic zones 2 can be communicated through water passing holes. When there are multiple second-stage anoxic zones 3, the multiple second-stage anoxic zones 3 can be communicated through water passing holes. When there are multiple second-stage aerobic zones 4, the multiple second-stage aerobic zones 4 can be communicated through water passing holes.

[0048] Referring to Figure 2As shown, according to some embodiments of the present application, the three-phase separator 5 comprises a first partition plate 508, a second partition plate 509 and a third partition plate 510 arranged at intervals, and the secondary anoxic zone 3 and the secondary aerobic zone 4 are located on both sides of the first partition plate 508. The sludge-water separation chamber 502 is formed between the first partition plate 508 and the second partition plate 509, and the water inlet channel 501 is formed between the second partition plate 509 and the third partition plate 510. The sludge-water inlet 511 is arranged between the first partition plate 508 and the second partition plate 509, and the sludge-water inlet 511 is in communication with the sludge-water separation chamber 502. The sludge-water outlet 503 is arranged between the first partition plate 508 and the third partition plate 510. By arranging the first partition plate 508, the second partition plate 509 and the third partition plate 510, the three-phase separator 5 can effectively divide the sewage into three different areas, i.e. the secondary anoxic zone 3, the secondary aerobic zone 4 and the sludge-water separation chamber 502, so as to realize effective separation and treatment of different components in the sewage.

[0049] Specifically, referring to Figure 2 As shown, in the present embodiment, the bottom of the first partition plate 508 is sealingly connected with the bottom of the third reaction tank, so as to divide the third reaction tank into the secondary anoxic zone 3 and the secondary aerobic zone 4. The lower end of the first partition plate 508 is bent towards the direction of the third partition plate 510 to form a sludge-water flow guide surface, and the third partition plate 510 is located above the first partition plate 508, so that the gap between the third partition plate 510 and the first partition plate 508 forms the sludge-water outlet 503. The separated sludge in the sludge-water separation chamber 502 enters the secondary aerobic zone 4 through the sludge-water outlet 503 under the flow guide action of gravity. The second partition plate 509 is located between the first partition plate 508 and the third partition plate 510, and the lower end of the second partition plate 509 is bent towards the direction of the first partition plate 508 to form a reduced opening at the lower end of the sludge-water separation chamber 502, so as to reduce the size of the sludge-water inlet 511, so that part of the sludge in the water inlet channel 501 can return to the secondary aerobic zone 4, and be collected at the end of the secondary aerobic zone 4 to enter the primary aerobic zone 2 for circulation, and the other part of the sludge in the water inlet channel 501 enters the sludge-water separation chamber 502 for separation of liquid and solid.

[0050] Referring to Figure 1 As shown, according to some embodiments of the present application, the first anoxic zone 1, the first aerobic zone 2 and the secondary anoxic zone 3 are each provided with a flow guide plate 13 for increasing the flow path of the sewage. The flow guide plate 13 can prolong the flow path of the sewage in the first anoxic zone 1, the first aerobic zone 2 and the secondary anoxic zone 3. Prolonging the flow path can make the sewage stay in the first anoxic zone 1, the first aerobic zone 2 and the secondary anoxic zone 3 for a longer time, which is conducive to the degradation and removal of organic matter in the wastewater by microorganisms. The arrangement of the flow guide wall can effectively guide the water flow to flow along the predetermined path, avoid the short circuit phenomenon caused by the direct channel, ensure that the wastewater is fully mixed and contacted with the microorganisms in the entire reactor, improve the treatment efficiency and removal rate of the wastewater, and improve the performance and stability of the treatment system.

[0051] According to some embodiments of the present invention, immobilized composite biological packing material and / or suspended MBBR biological packing material are provided in the primary anoxic zone 1, primary aerobic zone 2, secondary anoxic zone 3, and secondary aerobic zone 4. By providing immobilized composite biological packing material or suspended MBBR biological packing material in these zones, the bio-attachment area can be increased. Because the biological packing material has a large surface area, it can provide numerous microbial attachment points, which is conducive to the attachment and growth of bacteria and other microorganisms, thereby increasing the ability to biodegrade pollutants. Secondly, the biological packing material provides a favorable environment for bio-attachment, which is conducive to the reproduction and metabolic activities of various microorganisms, effectively accelerating the decomposition and removal of organic matter in wastewater and improving treatment efficiency.

[0052] See Figure 3 and Figure 4 As shown, the integrated biochemical reaction device provided in Embodiment 2 of the present invention differs from the integrated biochemical reaction device provided in Embodiment 1 of the present invention as follows.

[0053] In this embodiment, the integrated biochemical reaction equipment includes a first reaction tank, a second reaction tank, and a third reaction tank. A primary anoxic zone 1 is located within the first reaction tank, a primary aerobic zone 2 is located within the second reaction tank, and a three-phase separator 5 is located within the third reaction tank, with its bottom end sealed to the third reaction tank, dividing the third reaction tank into a secondary anoxic zone 3 and a secondary aerobic zone 4. The second reaction tank is located around the first reaction tank, so that the outer wall of the first reaction tank forms a guide plate 13 to increase the flow path of wastewater, thus eliminating the need for an additional guide plate 13.

[0054] The first reaction tank contains two primary anoxic zones 1, which are connected by water passages. The end of each primary anoxic zone 1 is connected to the beginning of a primary aerobic zone 2 via a third power reflux channel 14. The end of each primary aerobic zone 2 is connected to the beginning of a secondary anoxic zone 3 via a fourth power reflux channel 15. The end of each secondary anoxic zone 3 is connected to the beginning of a secondary aerobic zone 4 via water passages. The end of each primary aerobic zone 2 is connected to the beginning of each primary anoxic zone 1 via water passages, and the end of each secondary aerobic zone 4 is connected to the beginning of each primary aerobic zone 2 via water passages.

[0055] See Figure 5 and Figure 6 As shown, the integrated biochemical reaction device provided in Embodiment 3 of the present invention differs from the integrated biochemical reaction device provided in Embodiment 1 of the present invention as follows.

[0056] In the embodiment, the integrated biochemical reaction device comprises a first reaction tank, a second reaction tank and a third reaction tank arranged in sequence. The first-stage anoxic zone 1 is arranged in the first reaction tank, the first-stage aerobic zone 2 is arranged in the second reaction tank, and the three-phase separator 5 is arranged in the third reaction tank and is sealingly connected to the bottom end of the third reaction tank, thereby separating the third reaction tank into the second-stage anoxic zone 3 and the second-stage aerobic zone 4.

[0057] The length-width ratios of the first reaction tank, the second reaction tank and the third reaction tank are greater than those of the first reaction tank, the second reaction tank and the third reaction tank in the first embodiment, so that the hydraulic conditions of the embodiment are better than those of the first embodiment, thereby canceling the arrangement of the flow guide plate 13 and also canceling the overflow passage, and the hydraulic circulation can be achieved through the water passing holes.

[0058] The end of the first-stage anoxic zone 1 is connected to the start of the first-stage aerobic zone 2 through the fifth power backflow passage 16, the end of the first-stage aerobic zone 2 is connected to the start of the second-stage anoxic zone 3 through the water passing hole, and the end of the second-stage anoxic zone 3 is connected to the start of the second-stage aerobic zone 4 through the water passing hole. The end of the first-stage aerobic zone 2 is connected to the start of the first-stage anoxic zone 1 through the water passing hole, and the end of the second-stage aerobic zone 4 is connected to the start of the first-stage aerobic zone 2 through the sixth power backflow passage 17.

[0059] It can be seen that the second embodiment and the third embodiment differ from the first embodiment in that the second embodiment and the third embodiment adopt different forms of power backflow passages. In the second embodiment, the first-stage anoxic zone 1 is arranged in the middle, and the outer wall of the first-stage anoxic zone 1 forms the flow guide plate 13 for increasing the flow path of the sewage. In the third embodiment, the length-width ratios of the first reaction tank, the second reaction tank and the third reaction tank are greater than those of the first reaction tank, the second reaction tank and the third reaction tank in the first embodiment.

[0060] The sewage treatment method provided by the application will be described below. The sewage treatment method described below can be correspondingly referred to the integrated biochemical reaction device described above.

[0061] Referring to Figure 7 The sewage treatment method based on the integrated biochemical reaction device provided by the application includes the following steps.

[0062] S1, the sewage is introduced into the first-stage anoxic zone 1, and the carbon source in the sewage is mixed with the first-stage nitrification sludge mixed liquid returned to the first-stage anoxic zone 1 from the end of the first-stage aerobic zone 2 to generate a denitrification reaction, thereby obtaining a first-stage denitrification sludge mixed liquid.

[0063] S2, the first-stage denitrification sludge mixed liquid is introduced into the first-stage aerobic zone 2 to perform aerobic decarburization and nitrification under aerobic conditions, thereby obtaining a first-stage nitrification sludge mixed liquid.

[0064] S3, a part of the primary nitrification sludge mixture is returned to the primary anoxic zone 1 for circulation, and another part of the primary nitrification sludge mixture is introduced into the secondary anoxic zone 3, and further denitrification reaction occurs under the condition of carbon source, to obtain the secondary denitrification sludge mixture.

[0065] S4, the secondary denitrification sludge mixture is introduced into the secondary aerobic zone 4 for further decarburization and nitrification reaction under aerobic conditions, to obtain the secondary aerobic sludge mixture.

[0066] S5, a part of the secondary aerobic sludge mixture enters the three-phase separator 5 for separation of gas, liquid and solid, and the separated gas is returned to the secondary aerobic zone 4 for repeated use, the clear water is discharged from the biochemical system, and the sludge slides along the way into the secondary aerobic zone 4 and is collected at the end of the secondary aerobic zone 4, and is returned to the primary aerobic zone 2 with another part of the secondary aerobic sludge mixture for circulation.

[0067] Specifically, in step S1, the sewage first enters the primary anoxic zone 1, and under anoxic conditions, the carbon source in the sewage is mixed with the primary nitrification sludge mixture returned to the primary anoxic zone 1 from the end of the primary aerobic zone 2, and then the carbon source substances enter the primary nitrification sludge mixture, thereby creating an environment suitable for denitrification reaction. In the denitrification process, the nitrate nitrogen in the nitrification sludge is reduced to nitrogen gas, thereby forming the primary denitrification sludge mixture. This process can remove nitrogen elements in the sewage, and is a commonly used method in sewage denitrification treatment systems.

[0068] In step S2, the primary denitrification sludge mixture is introduced into the primary aerobic zone 2 for aerobic decarburization and nitrification reaction under aerobic conditions. The biochemical reaction oxidizes organic matter into carbon dioxide and water, and oxidizes ammonia nitrogen into nitrate nitrogen, resulting in the primary nitrification sludge mixture. This process is an aerobic biochemical reaction of the remaining carbon source pollutants and ammonia nitrogen in the sewage, and is also a commonly used method in sewage denitrification treatment systems.

[0069] In step S3, a part of the primary nitrification sludge mixture is returned to the primary anoxic zone 1 for circulation step S1, and another part of the primary nitrification sludge mixture is introduced into the secondary anoxic zone 3. In the secondary anoxic zone 3, the remaining nitrate nitrogen in the primary nitrification sludge mixture will further undergo denitrification reaction under the condition of carbon source, to produce the secondary denitrification sludge mixture, which can more thoroughly remove nitrogen elements in the sewage and improve the efficiency of denitrification treatment. Generally, the carbon source required for secondary denitrification is mostly precisely added or slightly over-added from outside to ensure the stability of total nitrogen in the effluent.

[0070] In step S4, the secondary denitrification sludge mixture enters the secondary aerobic zone 4, and further undergoes aerobic biochemical reaction under aerobic conditions to produce a secondary aerobic sludge mixture. In this process, the aerobic biochemical reaction can further oxidize and remove the remaining carbon source in the secondary denitrification sludge mixture and the ammonia nitrogen that is not nitrified for some reason, to ensure the stability of the effluent CODCr(or BOD5).

[0071] In step S5, a part of the secondary aerobic sludge mixture enters the three-phase separator 5 for separation of gas, liquid and solid, the gas is recycled to the secondary aerobic zone 4, the clean water is discharged from the biochemical system, and the sludge slides along the way into the secondary aerobic zone 4 and is collected at the end of the secondary aerobic zone 4, and is returned to the primary aerobic zone 2 with another part of the secondary aerobic sludge mixture to perform the cycle step S2. Through the recycling of sludge, various pollutants in the wastewater are continuously removed.

[0072] According to some embodiments of the present application, the dissolved oxygen at the end of the primary aerobic zone 2 is controlled to be less than or equal to 1.0 mg / L, and / or the oxidation-reduction potential at the end of the primary aerobic zone 2 is less than or equal to +100.0 mV, and / or the sludge concentration at the end of the secondary aerobic zone 4 is between 3 g / L and 10 g / L. By controlling the low dissolved oxygen concentration at the end of the primary aerobic zone 2, the adverse effects of the high return flow of the primary nitrification-denitrification on the anoxic zone can be effectively resolved, and the dissolved oxygen carried by the primary nitrification sludge mixture into the secondary anoxic zone 3 can be effectively reduced, the carbon source consumption for denitrification in the secondary anoxic zone 3 can be effectively reduced, the denitrification efficiency of the secondary anoxic zone 3 can be improved, and the generation of sludge can also be reduced. At the same time, the setting of the secondary aerobic zone 4 can effectively prevent the carbon source that is not fully utilized in the secondary denitrification from entering the effluent, and the carbon source breakthrough phenomenon can be avoided. By controlling the oxidation-reduction potential at the end of the primary aerobic zone 2 to be less than or equal to +100.0 mV, sufficient oxygen supply can be ensured, a good oxidation environment can be maintained, the degradation of organic matter and the removal of nitrogen can be promoted, and thus the treatment efficiency of the wastewater treatment system and the water quality can be improved. By controlling the sludge concentration at the end of the secondary aerobic zone 4 to be between 3 g / L and 10 g / L, stable treatment efficiency, reduced energy consumption and sludge treatment cost, improved system flexibility and robustness, and thus optimized wastewater treatment process can be achieved.

[0073] According to some embodiments of the present invention, the recirculation ratio from the primary aerobic zone 2 to the primary anoxic zone 1 is controlled to be greater than or equal to 300%, and the recirculation ratio from the secondary aerobic zone 4 to the primary aerobic zone 2 is controlled to be less than or equal to 200%. By using a higher recirculation ratio from the primary aerobic zone 2 to the primary anoxic zone 1, more nitrate nitrogen can be recirculated, improving the total nitrogen removal rate during the primary nitrification-denitrification process. Furthermore, the effluent from the primary aerobic zone can be fully utilized to dilute the influent, reducing the concentration of inhibitory pollutants in the wastewater and improving the shock resistance of the primary nitrification-denitrification biological treatment. Because the recirculation ratio from the secondary aerobic zone 4 to the primary aerobic zone 2 is relatively low, the secondary denitrification and secondary aerobic processes more closely resemble the pollutant removal principle of a plug flow reactor, resulting in greater pollutant removal and better effluent quality.

[0074] As can be seen from the description of the above embodiments, the integrated biochemical reaction equipment and wastewater treatment method provided by the present invention have at least the following advantages.

[0075] (1) The integrated biochemical reaction equipment has a simple structure, which not only saves space but also reduces the elevation loss of the reactor, which is conducive to energy-saving design. For example, it can greatly reduce the lifting height of the two-stage nitrification sludge mixed liquor recirculation, saving long-term operating energy consumption. In addition, it integrates the equipment room and supporting electrical equipment, and the equipment can be manufactured in advance in the processing plant, which greatly shortens the construction cycle of the sewage treatment plant.

[0076] (2) The use of three-phase separators simplifies the operation and management of traditional secondary sedimentation tanks. On the one hand, there is no need to configure the sludge suction scraper necessary for secondary sedimentation, which reduces the number of operation and management units. On the other hand, there is no need for independent sludge return facilities, which saves investment and operating energy consumption.

[0077] (3) The use of a three-phase separator can further increase the volume of the existing tank for use as a biochemical reaction zone, increase the biochemical reaction time, and help increase the amount of water treated and save the floor space.

[0078] (4) The air-lift reflux is used instead of the traditional mechanical water pump reflux for primary nitrification sludge mixed liquor reflux. This can achieve a large reflux ratio for primary nitrification and denitrification reactions with low energy consumption. Combined with the use of a three-phase separator, the average sludge concentration in the reactor can be greatly increased, the treatment efficiency per unit tank volume can be improved, and the land area can be further saved and the construction cost reduced.

[0079] (5) In the primary nitrification and denitrification reaction zone, under the premise of high reflux ratio and high sludge concentration, the adoption of low dissolved oxygen and / or redox potential control strategy is conducive to improving the utilization rate of dissolved oxygen, thereby reducing the operating energy consumption of the reactor, and at the same time greatly improving the shock resistance of the primary reaction zone.

[0080] (6) In the first stage nitrification and denitrification reaction zone, under the environment created by large reflux ratio, high sludge concentration and low dissolved oxygen, the removal rate of total nitrogen and Kjeldahl nitrogen in the first stage nitrification and denitrification reaction zone can be further improved.

[0081] (7) The low dissolved oxygen and / or redox potential control strategy used in the first stage nitrification and denitrification reaction zone is conducive to improving the denitrification ratio of simultaneous nitrification and denitrification and short-cut nitrification and denitrification in the first stage aerobic zone, saving energy consumption and carbon source consumption, and reducing the sludge yield in the first stage reaction zone.

[0082] (8) The low dissolved oxygen and / or redox potential control strategy used in the first stage nitrification and denitrification reaction zone provides better reaction conditions for denitrification in the second stage anoxic zone, which is conducive to saving carbon source consumption in the second stage denitrification, saving operating costs, and reducing the sludge yield in the second stage reaction zone.

[0083] (9) The three-phase separator refluxes the secondary aerobic sludge to the secondary aerobic zone along the way, and refluxes the secondary aerobic sludge mixed liquid to the first stage aerobic zone for cyclic reaction, without worrying about the influence of high dissolved oxygen reflux in the secondary aerobic zone on the denitrification in the first stage anoxic zone and the second stage anoxic zone. Even if the high dissolved oxygen is refluxed to the first stage aerobic zone, it can be reused, which is convenient to control and saves operating energy consumption.

[0084] (10) The setting of the second stage aerobic zone can effectively prevent the carbon source that is not fully utilized in the second stage denitrification from entering the effluent, causing carbon source breakthrough.

[0085] (11) The setting of the fixed composite biological filler and / or suspended MBBR biological filler in the first stage anoxic zone, the first stage aerobic zone, the second stage anoxic zone and the second stage aerobic zone can further improve the sludge concentration, improve the volume load of the biochemical reaction equipment, further save the land occupation, and improve the impact resistance of the biochemical reaction system.

[0086] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A sewage treatment method of an integrated biochemical reaction apparatus, characterized by, The integrated biochemical reaction device comprises: a first-stage anoxic zone, a water inlet pipe for feeding sewage being arranged at a first end of the first-stage anoxic zone; a first-stage aerobic zone, a first end of the first-stage aerobic zone being in communication with a last end of the first-stage anoxic zone, and a last end of the first-stage aerobic zone being in communication with the first end of the first-stage anoxic zone; a second-stage anoxic zone, a first end of the second-stage anoxic zone being in communication with a last end of the first-stage aerobic zone; a second-stage aerobic zone, a first end of the second-stage aerobic zone being in communication with a last end of the second-stage anoxic zone, and a last end of the second-stage aerobic zone being in communication with the first end of the first-stage aerobic zone; a three-phase separator, the three-phase separator comprising a water inlet channel, a sludge-water separation chamber, a sludge-water outlet and a clear water outlet, the first end of the water inlet channel being in communication with the second-stage aerobic zone, the last end of the water inlet channel being in communication with the sludge-water separation chamber and the sludge-water outlet, the sludge-water outlet being in communication with the sludge-water separation chamber, the first end of the second-stage aerobic zone being in communication with the sludge-water outlet, and the clear water outlet being arranged at a top of the sludge-water separation chamber; The method comprises: sewage is fed into the first-stage anoxic zone, carbon source in the sewage is mixed with first-stage nitrification sludge mixed liquor returned from a last end of the first-stage aerobic zone into the first-stage anoxic zone to form a first-stage denitrification sludge mixed liquor; the first-stage denitrification sludge mixed liquor is fed into the first-stage aerobic zone to perform aerobic decarburization and nitrification under aerobic conditions, thereby obtaining first-stage nitrification sludge mixed liquor; a part of the first-stage nitrification sludge mixed liquor is returned into the first-stage anoxic zone for circulation, and another part of the first-stage nitrification sludge mixed liquor is fed into the second-stage anoxic zone to further perform denitrification under the condition of carbon source, thereby obtaining second-stage denitrification sludge mixed liquor; the second-stage denitrification sludge mixed liquor is fed into the second-stage aerobic zone to further perform decarburization and nitrification under aerobic conditions, thereby obtaining second-stage aerobic sludge mixed liquor; a part of the second-stage aerobic sludge mixed liquor enters the three-phase separator to separate gas, liquid and solid, and the separated gas is returned to the second-stage aerobic zone for reuse, the clear water is discharged from the biochemical system, and the sludge slides along the way into the second-stage aerobic zone and is collected at the last end of the second-stage aerobic zone, and another part of the second-stage aerobic sludge mixed liquor is returned to the first-stage aerobic zone for circulation; dissolved oxygen at the last end of the first-stage aerobic zone is controlled to be less than or equal to 1.0 mg / L, oxidation-reduction potential at the last end of the first-stage aerobic zone is controlled to be less than or equal to +100.0 mV, and sludge concentration at the last end of the second-stage aerobic zone is controlled to be between 3 g / L and 10 g / L; a return ratio of the first-stage aerobic zone returned to the first-stage anoxic zone is controlled to be greater than or equal to 300%, and a return ratio of the second-stage aerobic zone returned to the first-stage aerobic zone is controlled to be less than or equal to 200%.

2. The wastewater treatment method of the integrated biochemical reaction apparatus according to claim 1, characterized by, The three-phase separator comprises a first partition plate, a second partition plate and a third partition plate arranged at intervals, and the second-stage anoxic zone and the second-stage aerobic zone are respectively located on two sides of the first partition plate. The first partition and the second partition form the sludge-water separation chamber, the second partition and the third partition form the water inlet channel, the first partition and the second partition are provided with a sludge-water inlet, the sludge-water inlet is communicated with the sludge-water separation chamber, and the first partition and the third partition are provided with the sludge-water outlet.

3. The wastewater treatment method of the integrated biochemical reaction apparatus according to claim 1, characterized by, The end of the first-stage aerobic zone is communicated with the head of the first-stage anoxic zone through a first power backflow channel. And / or, the end of the first-stage aerobic zone is communicated with the head of the first-stage anoxic zone through a water passing hole.

4. The wastewater treatment method of the integrated biochemical reaction apparatus according to claim 1, characterized by, The end of the second-stage aerobic zone is communicated with the head of the first-stage aerobic zone through a second power backflow channel. And / or, the end of the second-stage aerobic zone is communicated with the head of the first-stage aerobic zone through a water passing hole.

5. The wastewater treatment method of the integrated biochemical reaction apparatus according to any one of claims 1 to 4, characterized by, At least one of the first-stage anoxic zone, the first-stage aerobic zone and the second-stage anoxic zone is provided with a guide plate for increasing the flow path of sewage.

6. The wastewater treatment method of the integrated biochemical reaction apparatus according to any one of claims 1 to 4, characterized by, The first-stage aerobic zone is arranged at the periphery of the first-stage anoxic zone, and the outer wall of the first-stage anoxic zone forms a guide plate for increasing the flow path of sewage.

7. The wastewater treatment method of the integrated biochemical reaction apparatus according to any one of claims 1 to 4, characterized by, The first-stage anoxic zone, the first-stage aerobic zone, the second-stage anoxic zone and the second-stage aerobic zone are all provided with fixed composite biological fillers and / or suspended MBBR biological fillers.

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