Continuous flow aerobic granular sludge process sewage treatment method

Abstract

The invention provides a continuous flow aerobic granular sludge process system which is characterized in that a granular sludge section and a flocculent sludge section are sequentially arranged along the water inlet direction, the granular sludge section is sequentially provided with a sludge-water contact area and a granular sludge biochemical reaction area along the water inlet direction, and a sludge screener is arranged in the granular sludge biochemical reaction area close to the flocculent sludge section. The flocculent sludge section comprises a flocculent sludge biochemical reaction area. The invention also provides a continuous flow aerobic granular sludge process sewage treatment method. According to the sewage treatment method adopting the continuous flow aerobic granular sludge process, front-stage sludge granulation can be efficiently and rapidly achieved, it can be guaranteed that the sewage treatment effect is not reduced in the granulation process, the comprehensive sewage treatment capacity and the treatment effect are improved compared with those before transformation, the reaction time is shortened, the occupied area is reduced, and the cost is reduced. And the construction cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and relates to a continuous flow aerobic granular sludge sewage treatment method, and specifically to a continuous flow aerobic granular sludge sewage treatment device and method for sewage treatment. Background Art

[0002] In recent years, aerobic granular sludge wastewater biochemical treatment technology has attracted widespread attention due to its higher treatment efficiency and better sludge settling performance compared to traditional flocculent sludge biochemical treatment systems, and has been widely used in engineering projects abroad.

[0003] At present, the main method to realize the engineering application of aerobic granular sludge technology is to adopt sequencing batch reactor, that is, the biochemical reaction process is carried out in batches, and one batch is generally divided into three processes: "reaction", "precipitation", and "water inlet-water outlet". The sequencing batch reactor can easily create two basic conditions for the growth of aerobic granular sludge, one is the selective pressure screening of flocculent sludge (or light sludge), and the other is the priority nutrient supply (priority feeding) for granular sludge (or heavy sludge).

[0004] The actual sewage biochemical treatment system is mainly continuous flow, such as the AAO process, multi-stage AO process, Bardenpho process, etc. widely used in municipal sewage treatment plants, and aerobic biochemical process, AO process, etc. used in industrial wastewater treatment. It requires extremely high investment and is difficult to implement to transform the existing continuous flow sewage biochemical process into a sequencing batch process.

[0005] Some people also use the method of adding a bypass aerobic granular sludge generator on the basis of the existing continuous flow sewage biochemical treatment process to achieve a certain degree of sludge granulation. For example, a bypass cyclone separator or a high-load sedimentation device is used to separate a part of the sludge from light and heavy sludge. The separated light sludge is discharged from the treatment system, and the heavy sludge is returned to the treatment system, thereby creating a selection pressure condition, which is one of the basic conditions for the formation of aerobic granular sludge. After a long period of selection and washing, a small amount of granular sludge will appear in the main biochemical system. However, there are three problems with sludge granulation in this way. First, the cultivation time is long, and it often takes more than half a year to reach a certain degree of granulation; second, the degree of granulation is low, and it can only reach about 20% of the degree of granulation in municipal sewage applications; third, in the early stage of cultivation, the loss of light sludge will cause the excessive reduction of sludge concentration in the biochemical system, affecting the sewage treatment effect. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a continuous flow aerobic granular sludge sewage treatment method, which greatly improves the biochemical treatment efficiency through optimized structure, treatment steps and conditions, thereby shortening the reaction time, reducing land occupation and reducing construction costs.

[0007] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present invention provides a continuous flow aerobic granular sludge process system, in which a granular sludge section and a flocculent sludge section are sequentially arranged along the water inlet direction, and the granular sludge section is sequentially arranged along the water inlet direction. A sludge water contact zone and a granular sludge biochemical reaction zone are sequentially arranged, and a sludge screen is arranged in the area near the flocculent sludge section in the granular sludge biochemical reaction zone, and the flocculent sludge section includes a flocculent sludge biochemical reaction zone.

[0008] The second aspect of the present invention provides a continuous flow aerobic granular sludge method for treating sewage, which adopts the continuous flow aerobic granular sludge process system provided by the first aspect of the present invention, comprising the following steps:

[0009] 1) The sewage is introduced into the mud-water contact zone of the granular sludge section and then introduced into the granular sludge biochemical reaction zone of the granular sludge section for the first separation under the action of the sludge sifter to obtain the first heavy sludge;

[0010] 2) returning the first heavy sludge to the sludge-water contact zone to react with the sewage to form a first mixed liquid;

[0011] 3) the first mixed liquor is reintroduced into the granular sludge biochemical reaction zone for a first biochemical reaction, and then a second separation is performed under the action of a sludge sifter to obtain a second heavy sludge and a light sludge;

[0012] 4) Repeating steps 2) to 3) with the second heavy sludge, discharging excess heavy sludge after the first circulation reflux;

[0013] 5) introducing the second mixed liquid formed by the light sludge and the sewage into the flocculent sludge biochemical reaction zone of the flocculent sludge section for a second biochemical reaction, and then performing solid-liquid separation in the sedimentation zone to obtain a clear liquid and residual light sludge, and discharging the clear liquid;

[0014] 6) The residual light sludge is returned to the flocculent sludge biochemical reaction zone, and step 5) is repeated to discharge the excess light sludge after a second cycle of return.

[0015] As described above, the continuous flow aerobic granular sludge method for sewage treatment provided by the present invention has the following beneficial effects:

[0016] (1) The present invention provides a continuous flow aerobic granular sludge method for sewage treatment. After the existing sewage biochemical system is modified, it can not only achieve the sludge granulation of the previous stage efficiently and quickly, and most pollutants are efficiently degraded by the granular sludge; but also ensure that the sewage treatment effect is not reduced during the granulation process. After the sludge granulation reaches the designed degree, the comprehensive sewage treatment capacity and treatment effect will be improved compared with before the modification.

[0017] (2) The present invention provides a continuous flow aerobic granular sludge method for sewage treatment. For new projects, the biochemical treatment system using this technology is simple in design, which greatly improves the biochemical treatment efficiency, thereby shortening the reaction time, reducing land occupation, and reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a flow chart of a continuous flow aerobic granular sludge process system using a sedimentation tank.

[0019] Figure 2 Shown is a flow structure diagram of a continuous flow aerobic granular sludge process system using a built-in precipitator.

[0020] Figure 3 Shown is a flow structure diagram of a continuous flow aerobic granular sludge process system using a membrane bioreactor (MBR).

[0021] Reference numerals

[0022] 1 Granular sludge stage

[0023] 11 Mud and water contact area

[0024] 12 Granular sludge biochemical reaction zone

[0025] 13 Sludge Screener

[0026] 14 First reflux pipe

[0027] 15 First discharge pipe

[0028] 2 Flocculent sludge section

[0029] 21 Flocculent sludge biochemical reaction zone

[0030] 22 Sedimentation Zone

[0031] 221 Sedimentation Tank

[0032] 222 Sedimentation Tank

[0033] 223 Membrane Filter

[0034] 23 Second return pipe

[0035] 24 Second discharge pipe

[0036] 25 Third return pipe

[0037] 26 Third discharge pipe

[0038] 3 Water inlet pipe

[0039] 4 Water outlet pipe

[0040] 5 Downstream pipe DETAILED DESCRIPTION

[0041] See also Figures 1 to 3 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0042] The first aspect of the present invention provides a continuous flow aerobic granular sludge process system, such as Figure 1-3 As shown, a granular sludge section and a flocculent sludge section are sequentially provided along the water inlet direction, the granular sludge section is sequentially provided with a mud-water contact zone and a granular sludge biochemical reaction zone along the water inlet direction, a sludge screen is provided in the area near the flocculent sludge section in the granular sludge biochemical reaction zone, and the flocculent sludge section includes the flocculent sludge biochemical reaction zone.

[0043] In the above system, if Figure 1-3 As shown, the mud-water contact area is connected with a water inlet pipe.

[0044] In the above system, if Figure 1-3 As shown, the mud-water contact zone is an anaerobic reaction unit.

[0045] In one embodiment, the anaerobic reaction unit is an anaerobic reaction tank or an anaerobic reactor.

[0046] The mud-water contact zone is a reaction zone where the returned heavy sludge, i.e., granular sludge, fully contacts the incoming sewage.

[0047] In the above system, if Figure 1-3As shown, the granular sludge biochemical reaction zone is selected from one of an aerobic reaction unit or a combined reaction unit, the combined reaction unit includes an aerobic reaction unit and other reaction units, and the other reaction units are selected from at least one of an anaerobic reaction unit or an anoxic reaction unit.

[0048] In one embodiment, the aerobic reaction unit is an aerobic reaction tank or an aerobic reactor.

[0049] In one embodiment, the anaerobic reaction unit is an anaerobic reaction tank or an anaerobic reactor.

[0050] In one embodiment, the anoxic reaction unit is an anoxic reaction tank or an anoxic reactor.

[0051] The granular sludge biochemical reaction zone is the place where the biochemical reaction of microorganisms in the granular sludge to degrade pollutants occurs.

[0052] In the above system, if Figure 1-3 As shown, the sludge screen is the sedimentation device in the patent application "2024116206648 A sedimentation device and its biochemical pool and sewage treatment method".

[0053] Through the screening action of the above-mentioned sludge screener, the "selective pressure screening" condition is created, so that the heavy sludge is retained in the granular sludge biochemical reaction zone of the granular sludge section, and the light sludge is eliminated from the granular sludge section; and the sewage enters from the mud-water contact zone at the front end of the granular sludge section. The pollutants in the sewage are nutrients for the growth of microorganisms, so the granular sludge will give priority to the use of nutrients, creating "priority feeding" conditions, and the light sludge can use the few remaining nutrients in the flocculent sludge biochemical reaction zone of the flocculent sludge section at the back, thereby inhibiting the competitive growth of the light sludge.

[0054] In the above system, if Figure 1-3 As shown, the sludge screener is connected to the water inlet end of the mud-water contact zone through a first return pipe to achieve the return of heavy sludge, namely granular sludge, and the sludge screener is also connected to a first discharge pipe.

[0055] In one embodiment, if Figure 1-3 As shown, the first reflux pipe passes through the granular sludge biochemical reaction zone and is connected to the sludge-water contact zone, so as to realize the circulation and reflux of heavy sludge, i.e. granular sludge, and enrich it in the granular sludge biochemical reaction zone.

[0056] In one embodiment, if Figure 1-3 As shown, the first discharge pipe runs through the granular sludge biochemical reaction zone and the outlet of the first discharge pipe is located outside the granular sludge biochemical reaction zone, so as to discharge the excess heavy sludge generated by the growth and proliferation of microorganisms.

[0057] The flocculent sludge biochemical reaction zone is a place where biochemical reactions of microorganisms in the flocculent sludge to degrade pollutants occur.

[0058] In the above system, if Figure 1-3 As shown, the flocculent sludge biochemical reaction zone is selected from at least one of an aerobic reaction unit, an anaerobic reaction unit or an anoxic reaction unit.

[0059] In one embodiment, the aerobic reaction unit is an aerobic reaction tank or an aerobic reactor.

[0060] In one embodiment, the anaerobic reaction unit is an anaerobic reaction tank or an anaerobic reactor.

[0061] In one embodiment, the anoxic reaction unit is an anoxic reaction tank or an anoxic reactor.

[0062] The flocculent sludge biochemical reaction zone of the flocculent sludge section supplements the pollutant degradation effect of the granular sludge section, especially in the initial start-up of the sludge screener, the granular sludge growth of the granular sludge section is insufficient and the treatment effect is insufficient. At this time, a higher proportion of residual pollutants enter the flocculent sludge biochemical reaction zone of the flocculent sludge section, and the pollution is further degraded.

[0063] In the above system, if Figure 1-3 As shown, the flocculent sludge section also includes a sedimentation zone, and the sedimentation zone is arranged in the flocculent sludge biochemical reaction zone or is connected to the water outlet end of the flocculent sludge biochemical reaction zone.

[0064] In one embodiment, if Figure 1-3 As shown, the sedimentation zone is selected from at least one of a sedimentation tank, a sedimentation vessel or a membrane filter.

[0065] In a preferred embodiment, Figure 1 As shown, the sedimentation tank is a secondary sedimentation tank. The secondary sedimentation tank is a conventionally used secondary sedimentation tank.

[0066] In a preferred embodiment, Figure 2 As shown, the precipitator is a built-in precipitator. The built-in precipitator is the precipitator form in the patent application "2024116206648 A precipitator and its biochemical pool and sewage treatment method".

[0067] In a preferred embodiment, Figure 3 As shown, the membrane filter is a membrane bioreactor (MBR). The membrane bioreactor is a conventionally used membrane bioreactor (MBR).

[0068] In a preferred embodiment, Figure 1 As shown, when the sedimentation zone is a sedimentation tank, the sedimentation tank is connected to the water outlet end of the flocculent sludge biochemical reaction zone.

[0069] In a further preferred embodiment, Figure 1 As shown, the sedimentation tank is connected with the water outlet end of the flocculent sludge biochemical reaction zone through a downstream pipe.

[0070] In a further preferred embodiment, Figure 1 As shown, the sedimentation tank is connected to the water inlet end of the flocculent sludge biochemical reaction zone through the second reflux pipe to realize the circulation and reflux of the flocculent sludge, and enrich it in the flocculent sludge biochemical reaction zone; the sedimentation tank is also connected to a second discharge pipe. The second discharge pipe is used to discharge the excess flocculent sludge generated by the growth and proliferation of microorganisms.

[0071] In a preferred embodiment, Figure 2-3 As shown, when the sedimentation zone is a sedimentation vessel or a membrane filter, the sedimentation vessel or the membrane filter is located in the area close to the water outlet in the flocculent sludge biochemical reaction zone.

[0072] In a further preferred embodiment, Figure 2-3 As shown, the flocculent sludge biochemical reaction zone is connected with a third reflux pipe and a third discharge pipe, and the third reflux pipe is respectively connected with the water inlet end and the water outlet end of the flocculent sludge biochemical reaction zone to realize the reflux of the flocculent sludge and enrich it in the flocculent sludge biochemical reaction zone; one end of the third discharge pipe is connected with the flocculent sludge biochemical reaction zone to discharge excess flocculent sludge generated by the growth and proliferation of microorganisms.

[0073] In one embodiment, if Figure 1-3 As shown, the water outlet end of the sedimentation zone is connected to a water outlet pipe.

[0074] The second aspect of the present invention provides a continuous flow aerobic granular sludge method for treating sewage, which adopts the continuous flow aerobic granular sludge process system provided by the first aspect of the present invention, comprising the following steps:

[0075] 1) The sewage is introduced into the mud-water contact zone of the granular sludge section and then introduced into the granular sludge biochemical reaction zone of the granular sludge section for the first separation under the action of the sludge sifter to obtain the first heavy sludge;

[0076] 2) returning the first heavy sludge to the sludge-water contact zone to react with the sewage to form a first mixed liquid;

[0077] 3) the first mixed liquor is reintroduced into the granular sludge biochemical reaction zone for a first biochemical reaction, and then a second separation is performed under the action of a sludge sifter to obtain a second heavy sludge and a light sludge;

[0078] 4) Repeating steps 2) to 3) with the second heavy sludge, discharging excess heavy sludge after the first circulation reflux;

[0079] 5) introducing the second mixed liquid formed by the light sludge and the sewage into the flocculent sludge biochemical reaction zone of the flocculent sludge section for a second biochemical reaction, and then performing solid-liquid separation in the sedimentation zone to obtain a clear liquid and residual light sludge, and discharging the clear liquid;

[0080] 6) The residual light sludge is returned to the flocculent sludge biochemical reaction zone, and step 5) is repeated to discharge the excess light sludge after a second cycle of return.

[0081] In step 1), the sewage is input into the mud-water contact area through the water inlet pipe.

[0082] In step 1), in the first separation, the sludge separation load of the sludge screener is 3 to 10 m / h.

[0083] In step 2), if Figure 1-3 As shown, the first heavy sludge flows back to the water inlet end of the mud-water contact zone through the first return pipe.

[0084] In step 2), the reaction time of the mud-water contact reaction is 1-3 hours.

[0085] In step 2), the mud-water contact reaction is carried out by stirring and mixing reaction, and the stirring method is selected from one of mechanical stirring and air stirring. The mud and water can be fully mixed and reacted in the mud-water contact area to form a first mixed liquid for inhibiting the growth of flocculent sludge.

[0086] During the formation of the above-mentioned first mixed liquor, the sewage enters the sewage contact area of ​​the granular sludge section and comes into contact with the returned first heavy sludge (i.e., returned granular sludge). Since the returned granular sludge is mainly granular sludge due to the screening effect of the sludge screener, the granular sludge preferentially utilizes the nutrients in the incoming water, thus avoiding the competition of flocculent sludge for nutrients, that is, creating preferential feeding conditions for the growth of granular sludge and inhibiting the growth of flocculent sludge.

[0087] In step 3), the first biochemical reaction is selected from one of an aerobic reaction or a combined reaction, the combined reaction includes an aerobic reaction and other reactions, and the other reactions are selected from at least one of an anaerobic reaction or an anoxic reaction.

[0088] The first biochemical reaction is the biodegradation of pollutants in sewage by microorganisms in the granular sludge in the granular sludge biochemical reaction zone. The first biochemical reaction can be a single aerobic reaction, or a combination of "anaerobic + aerobic", "anoxic + aerobic", "anaerobic + anoxic + aerobic", "anaerobic + aerobic + anoxic" and the like.

[0089] In step 3), in the second separation, the sludge separation load of the sludge screener is 3 to 10 m / h. Based on the sludge separation load (selective pressure) of the sedimentation velocity, that is, the selective pressure elutriation effect, the light sludge in the sludge has a poor sedimentation velocity, and the heavy sludge has a good sedimentation velocity. The heavy sludge that is higher than the separation load of the sludge screener will not be discharged with the effluent of the sludge screener, and will remain in the granular sludge section; the light sludge that is lower than the separation load of the sludge screener will be discharged with the effluent of the sludge screener, eliminated from the granular sludge section, and enter the subsequent flocculent sludge section.

[0090] The above-mentioned sludge screener is used as a means of separating light sludge and heavy sludge in the biochemical reaction tank, creating selective pressure screening conditions; the sludge screener divides the biochemical reaction process into two sections, the front section is a granular sludge section (heavy sludge section), and the back section is a flocculent sludge section (light sludge section). The granular sludge in the front stage preferentially contacts and utilizes nutrients, thereby creating preferential feeding conditions for the granular sludge; at the same time, the flocculent sludge section retains a high concentration of flocculent sludge, which can ensure the sewage treatment effect during the sludge granulation culture process.

[0091] The first mixed liquid enters the sludge screener for separation, and the sludge screener creates the selective pressure screening conditions for the sludge. Specifically, the light sludge with a sedimentation performance lower than the screening selective pressure flows out of the sludge screener with the sewage to the subsequent flocculent sludge section; the heavy sludge with a sedimentation performance higher than the screening selective pressure, that is, the granular sludge with a large particle size will not be carried out by the effluent of the sludge screener and will be retained in the granular sludge section, forming mixing and circulation in the granular sludge section, and the excess heavy sludge due to the growth and proliferation of microorganisms is discharged from the system in the form of excess granular sludge.

[0092] In step 4), the excess heavy sludge is discharged through the first discharge pipe.

[0093] In step 5), the second biochemical reaction is selected from at least one of an aerobic reaction, an anaerobic reaction or an anoxic reaction.

[0094] The second biochemical reaction can be a single aerobic reaction, an anaerobic reaction or an anoxic reaction, or it can be an "anaerobic + aerobic" combination reaction, a "anoxic + aerobic" combination reaction, a "anaerobic + anoxic" combination reaction, a "anaerobic + anoxic + aerobic" combination reaction, a "anaerobic + aerobic + anoxic" combination reaction, or the like.

[0095] In step 5), if Figure 1-3 As shown, the clear liquid is discharged through the outlet pipe.

[0096] In step 6), if Figure 1-3 As shown, the residual light sludge flows back to the water inlet end of the flocculent sludge biochemical reaction zone through the second return pipe or the third return pipe.

[0097] In step 6), if Figure 1-3 As shown, the excess light sludge is discharged through the second discharge pipe.

[0098] During the second biochemical reaction and the second circulation backflow, the sewage and light sludge flowing out of the sludge screen form a second mixed liquid, and the biochemical reaction continues in the light sludge section. The flocculent sludge biochemical reaction zone can be divided into anaerobic zone, anoxic zone, aerobic zone, or a combination of several reaction forms according to needs. The sewage treated in the flocculent sludge biochemical reaction zone carries the sludge through a sedimentation tank or a sedimentator or a membrane filter for solid-liquid separation, and the clear liquid is discharged from the system. The light sludge is refluxed to form a cycle, and the excess light sludge due to the growth and proliferation of microorganisms is discharged from the system in the form of excess flocculent sludge.

[0099] This method highlights two creative conditions for granular sludge, one is the "selective pressure screening" condition, and the other is the "priority" feeding condition. Specifically, in the above system, the "light-heavy" separation of sludge is achieved by adding a sifter inside, thereby dividing the biochemical reaction process into two parts - the granular sludge reaction section and the flocculent sludge reaction section. This not only utilizes the efficient treatment effect of granular sludge, but also ensures that there is a flocculent sludge section at the back to supplement the reaction effect, so as to avoid insufficient treatment effect during the sludge granulation process.

[0100] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0101] Comparative Example 1

[0102] A municipal sewage treatment plant in Zhejiang, with a design scale of 20,000m 3 / d, the outgoing water complies with the local emission standards of Zhejiang Province, and the sewage biochemical system adopts the traditional AAO continuous flow activated sludge biochemical treatment process (anaerobic + anoxic + aerobic + secondary sedimentation tank) system.

[0103] According to the designed water volume, the hydraulic retention time of the existing anaerobic reaction tank is 2h, the hydraulic retention time of the anoxic reaction tank is 6h, and the hydraulic retention time of the aerobic reaction tank is 8h, that is, the total biochemical hydraulic retention time is 16h, and the surface load of the secondary sedimentation tank is 1.0m / h.

[0104] The sewage biochemical system has no sludge granulation enhancement measures, and the sludge in the biochemical system exists in the form of flocculent sludge. The sewage biochemical system has the disadvantages of low pollutant degradation efficiency, low biochemical denitrification efficiency, low carbon source utilization rate, poor sludge sedimentation performance, and large sludge production.

[0105] During the rainy season, the maximum hourly treatment capacity of the sewage plant is only 1100m3 3 / h; in non-winter season (water temperature entering the biochemical system is higher than 15℃), the total nitrogen in the effluent from the secondary sedimentation tank is 9-12mg / L, and the total phosphorus is 0.6-0.8mg / L; in winter season (water temperature entering the biochemical system is lower than 15℃), the total nitrogen in the effluent from the secondary sedimentation tank is 10-15mg / L, and an external carbon source (sodium acetate solution) worth RMB 3,000 needs to be added every day to ensure that the total nitrogen in the outlet water is stabilized below 12mg / L (discharge standard); on average throughout the year, the amount of sludge produced per 10,000 tons of sewage is 9t (calculated as sludge with a water content of 80%), and the average cost of treating and outsourcing each ton of sludge is RMB 400.

[0106] Example 1

[0107] Use Figure 1 The continuous flow aerobic granular sludge wastewater biochemical treatment process shown in the figure carries out in-situ transformation of the plant's biochemical system (anaerobic + anoxic + aerobic + secondary sedimentation tank). The main transformation measures are: retaining the original anaerobic reaction tank and anoxic reaction tank (hereinafter referred to as the front anoxic reaction tank) without transformation; dividing the aerobic reaction tank into three sections, namely the front aerobic reaction tank (according to the original design water volume, hydraulic retention time 3h), the rear anoxic reaction tank (according to the original design water volume, hydraulic retention time 3h), and the rear aerobic reaction tank (according to the original design water volume, hydraulic retention time 2h), that is, the biochemical tank is transformed into an AAOAO five-stage type. A sludge screener is added to the rear anoxic reaction tank. The screener used adopts the sedimentation tank form in the patent application "2024116206648 A sedimentation tank and its biochemical tank and sewage treatment method", with a designed sedimentation load of 7.5m 3 / m 2 ·h (i.e. the sludge separation load of the screener is 7.5m / h). The anaerobic reaction tank is used as the mud-water contact zone. In this way, the anaerobic reaction tank (mud-water contact zone), the front anoxic reaction tank, the front aerobic reaction tank, the rear anoxic reaction tank, the sludge screener and the corresponding pumps and pipelines constitute the "granular sludge section", among which the front anoxic reaction tank, the front aerobic reaction tank and the rear anoxic reaction tank constitute the "granular sludge biochemical reaction zone". The rear aerobic reaction tank and the original secondary sedimentation tank as well as the corresponding pumps and pipelines constitute the "flocculent sludge section", and the rear aerobic reaction tank is the "flocculent sludge biochemical reaction zone".

[0108] The specific processing includes the following steps:

[0109] 1) The sewage is introduced into the mud-water contact area of ​​the granular sludge section through the water inlet pipe and then introduced into the granular sludge biochemical reaction area of ​​the granular sludge section through the downstream pipe for the first separation under the action of the sludge sifter. The sludge separation load is 7.5m / h to obtain the first heavy sludge;

[0110] 2) The first heavy sludge is refluxed to the water inlet end of the mud-water contact zone through the first reflux pipe, and is subjected to mud-water contact reaction (anaerobic) with the sewage under mechanical stirring for 2 hours to form a first mixed liquid;

[0111] 3) The first mixed liquor is introduced into the granular sludge biochemical reaction zone for the first biochemical reaction (anoxic + aerobic + anoxic), and then the second separation is performed under the action of the sludge sifter, and the sludge separation load is 7.5m / h to obtain the second heavy sludge and light sludge;

[0112] 4) Repeating steps 2) to 3) with the second heavy sludge, after the first circulation reflux, the excess heavy sludge due to the growth and proliferation of microorganisms is discharged through the first discharge pipe;

[0113] 5) The second mixed liquid formed by the light sludge and the sewage is introduced into the flocculent sludge biochemical reaction zone of the flocculent sludge section through the downstream pipe for the second biochemical reaction (aerobic), and then solid-liquid separation is carried out in the secondary sedimentation tank. The surface load of the secondary sedimentation tank is 1.0m / h, and the clear liquid and residual light sludge are obtained, and the clear liquid is discharged through the outlet pipe;

[0114] 6) The residual light sludge is returned to the flocculent sludge biochemical reaction zone through the second reflux pipe, and step 5) is repeated to discharge the excess light sludge through the second discharge pipe after the second circulation reflux.

[0115] Compared with comparative example 1, after modification, the following gain effects are achieved:

[0116] 1) Increase: The sewage treatment plant can withstand a larger inflow. During the rainy season, the maximum hourly treatment capacity is increased to 1800m3 3 / h, an increase of 64% compared with before the transformation;

[0117] 2) Efficiency enhancement: In non-winter season, the total nitrogen in the effluent from the secondary sedimentation tank is 6-8 mg / L, and the total phosphorus is 0.3-0.5 mg / L, and the effluent from the biochemical system is better; in winter, the total nitrogen in the effluent from the secondary sedimentation tank is 7-9 mg / L, and no external carbon source is needed to ensure that the total nitrogen in the effluent is stable below the discharge standard of 10 mg / L;

[0118] 3) Consumption reduction: reduce or even eliminate external carbon source consumption;

[0119] 4) Sludge reduction: On average, the amount of sludge produced per 10,000 tons of sewage is 6 tons (based on sludge with a water content of 80%), which is 33% lower than before the transformation;

[0120] 5) Improve production security: increase the volume and increase the efficiency, which greatly improves the production security of the sewage treatment plant;

[0121] 6) Save operating costs: Reducing external carbon source consumption and reducing sludge production can reduce operating costs. After the transformation, the plant saved 3,000 yuan / day in external carbon source costs in winter and 2,400 yuan per day in sludge treatment and disposal costs. The two items together can save 5,400 yuan / day in operating costs.

[0122] Example 2

[0123] A new sewage treatment station was built in a printing and dyeing factory. The biochemical treatment system adopts Figure 2 The continuous flow aerobic granular sludge wastewater biochemical treatment process system shown.

[0124] Designed sewage treatment capacity: 200m 3 / h. The hydraulic retention time of the mud-water contact zone is 2h, and mechanical stirring is adopted. The granular sludge biochemical reaction zone of the granular sludge section is composed of "anaerobic tank + pre-aerobic tank", of which the hydraulic retention time of the anaerobic tank is 6h, and the hydraulic retention time of the pre-aerobic tank is 6h. The mud-water screen adopts the precipitator form in the patent application "2024116206648 A precipitator and its biochemical tank and sewage treatment method", and the separation load is 6m / h. The flocculent sludge biochemical reaction zone of the flocculent sludge section is composed of a post-aerobic tank, and the hydraulic retention time of the post-aerobic tank is 6h. A built-in precipitator is adopted. The precipitator adopts the precipitator form in the patent application "2024116206648 A precipitator and its biochemical tank and sewage treatment method", and the separation load is 2m / h.

[0125] The total hydraulic retention time of the entire biochemical treatment system is 20 hours (including the time in the precipitator). The old sewage treatment plant of the printing and dyeing unit adopts the traditional flocculent activated sludge method, with a total hydraulic retention time of 40 hours (including the time in the secondary sedimentation tank). The efficiency of the new plant's sewage biochemical system has doubled, greatly saving construction land and construction costs.

[0126] The specific processing includes the following steps:

[0127] 1) The sewage is introduced into the mud-water contact area of ​​the granular sludge section through the water inlet pipe and then introduced into the granular sludge biochemical reaction area of ​​the granular sludge section through the downstream pipe for the first separation under the action of the sludge sifter. The sludge separation load is 8m / h to obtain the first heavy sludge;

[0128] 2) The first heavy sludge is refluxed to the water inlet end of the mud-water contact zone through the first reflux pipe, and is subjected to mud-water contact reaction (anaerobic) with the sewage under mechanical stirring for 3 hours to form a first mixed liquid;

[0129] 3) The first mixed liquor is introduced into the granular sludge biochemical reaction zone for the first biochemical reaction (anaerobic + aerobic), and then the second separation is carried out under the action of the sludge sifter, and the sludge separation load is 8m / h to obtain the second heavy sludge and light sludge;

[0130] 4) Repeating steps 2) to 3) with the second heavy sludge, after the first circulation reflux, the excess heavy sludge due to the growth and proliferation of microorganisms is discharged through the first discharge pipe;

[0131] 5) The second mixed liquid formed by the light sludge and the sewage is introduced into the flocculent sludge biochemical reaction zone of the flocculent sludge section through the downstream pipe for the second biochemical reaction (aerobic), and then solid-liquid separation is performed in the sedimentation zone to obtain a clear liquid and residual light sludge, and the clear liquid is discharged through the outlet pipe;

[0132] 6) The residual light sludge is returned to the flocculent sludge biochemical reaction zone through the second reflux pipe, and step 5) is repeated to discharge the excess light sludge through the second discharge pipe after the second circulation reflux.

[0133] Comparative Example 2

[0134] A municipal sewage treatment plant adopts the MBR biochemical treatment process (anaerobic + anoxic + aerobic + MBR), and other processes and structures are similar to those of Comparative Example 1.

[0135] Example 3

[0136] Use Figure 3 The continuous flow aerobic granular sludge process for sewage biochemical treatment is modified for the system structure of comparative example 2, and the other corresponding conditions are the same as those of example 1. After the modification, it is found that the continuous flow aerobic granular sludge process system of the present invention can improve the MBR process, and its technical effect is significantly improved compared with comparative example 2.

[0137] Comparative Examples 3-4

[0138] The newly built sewage treatment plant adopts the same biochemical treatment process as in Example 1, and its biochemical system adopts a continuous flow aerobic granular sludge sewage treatment process, and the specific data are shown in Table 1. As can be seen from Table 1, only when the treatment conditions conforming to the method of the present invention are adopted, the treatment effect is better.

[0139] Table 1

[0140] project Example 1 Comparative Example 3 Comparative Example 4 Sludge separation load (m / h) 7.5 2 11 Mud-water contact reaction time (h) 2 4 0.5 Total nitrogen concentration in the effluent from the secondary sedimentation tank (mg / L) ≤10 15 13 Dosage of external carbon source in winter (mgCOD equivalent / L sewage) / 10 5 Sludge production per 10,000 tons of sewage (based on sludge with a water content of 80%, t) 6 8 10 Save external carbon source cost (yuan / day) 3000 1000 2000 Save sludge treatment and disposal costs (yuan / day) 2400 1600 800

[0141] In summary, the continuous flow aerobic granular sludge method for sewage treatment provided by the present invention can not only efficiently and quickly realize the sludge granulation of the previous stage, but also ensure that the sewage treatment effect is not reduced during the granulation process. The comprehensive sewage treatment capacity and treatment effect will be improved compared with before the transformation, shortening the reaction time, reducing the land occupation, and reducing the construction cost. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0142] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A continuous flow aerobic granular sludge process system, characterized in that: A granular sludge section (1) and a flocculent sludge section (2) are sequentially arranged along the water inlet direction; the granular sludge section (1) is sequentially arranged along the water inlet direction with a sludge-water contact zone (11) and a granular sludge biochemical reaction zone (12); a sludge sifter (13) is arranged in the area of ​​the granular sludge biochemical reaction zone (12) close to the flocculent sludge section (1); and the flocculent sludge section (2) includes a flocculent sludge biochemical reaction zone (21).

2. The continuous flow aerobic granular sludge process system according to claim 1, characterized in that: The mud-water contact zone (11) is connected to a water inlet pipe (3); and / or the mud-water contact zone (11) is an anaerobic reaction unit.

3. The continuous flow aerobic granular sludge process system according to claim 1, characterized in that: The granular sludge biochemical reaction zone (12) is selected from one of an aerobic reaction unit or a combined reaction unit, the combined reaction unit comprises an aerobic reaction unit and other reaction units, and the other reaction unit is selected from at least one of an anaerobic reaction unit or an anoxic reaction unit.

4. The continuous flow aerobic granular sludge process system according to claim 1, characterized in that: The sludge screen (13) is connected to the water inlet end of the sludge-water contact zone (11) via a first return pipe (14), and the sludge screen (13) is also connected to a first discharge pipe (15).

5. The continuous flow aerobic granular sludge process system according to claim 4, characterized in that: Includes any one or more of the following conditions: A1) the first reflux pipe (14) passes through the granular sludge biochemical reaction zone (12) and is connected to the sludge-water contact zone (11); A2) The first discharge pipe (15) passes through the granular sludge biochemical reaction zone (12), and the outlet of the first discharge pipe (15) is located outside the granular sludge biochemical reaction zone (12).

6. The continuous flow aerobic granular sludge process system according to claim 1, characterized in that: The flocculent sludge biochemical reaction zone (21) is selected from at least one of an aerobic reaction unit, an anaerobic reaction unit or an anoxic reaction unit; And / or, the flocculent sludge section further comprises a sedimentation zone, and the sedimentation zone (22) is arranged in the flocculent sludge biochemical reaction zone (21) or is connected to the water outlet end of the flocculent sludge biochemical reaction zone (21).

7. The continuous flow aerobic granular sludge process system according to claim 6, characterized in that: The precipitation zone (22) includes any one or more of the following conditions: B1) the sedimentation zone (22) is selected from at least one of a sedimentation tank, a sedimentation vessel or a membrane filter; preferably, when the sedimentation zone (22) is a sedimentation tank, the sedimentation tank is connected to the water outlet of the flocculent sludge biochemical reaction zone; B2) The water outlet end of the sedimentation zone (22) is connected to a water outlet pipe (4).

8. The continuous flow aerobic granular sludge process system according to claim 7, characterized in that: B1) includes any one or more of the following conditions: B11) the sedimentation tank (221) is connected to the water outlet of the flocculent sludge biochemical reaction zone (21) via a downstream pipe (5); B12) the sedimentation tank (221) is connected to the water inlet end of the flocculent sludge biochemical reaction zone (21) via a second return pipe (23); the sedimentation tank (221) is also connected to a second discharge pipe (24); B13) When the sedimentation zone (221) is a sedimentation vessel or a membrane filter, the sedimentation vessel or the membrane filter is located in the area near the water outlet end of the flocculent sludge biochemical reaction zone (21); preferably, the flocculent sludge biochemical reaction zone (21) is connected with a third return pipe (25) and a third discharge pipe (26), and the third return pipe (25) is respectively connected to the water inlet end and the water outlet end of the flocculent sludge biochemical reaction zone (21); one end of the third discharge pipe (26) is connected to the flocculent sludge biochemical reaction zone (21).

9. A continuous flow aerobic granular sludge method for treating sewage, characterized in that: The continuous flow aerobic granular sludge process system according to any one of claims 1 to 8 comprises the following steps: 1) The sewage is introduced into the mud-water contact zone of the granular sludge section and then introduced into the granular sludge biochemical reaction zone of the granular sludge section for the first separation under the action of the sludge sifter to obtain the first heavy sludge; 2) returning the first heavy sludge to the sludge-water contact zone to react with the sewage to form a first mixed liquid; 3) the first mixed liquor is reintroduced into the granular sludge biochemical reaction zone for a first biochemical reaction, and then a second separation is performed under the action of a sludge sifter to obtain a second heavy sludge and a light sludge; 4) Repeating steps 2) to 3) with the second heavy sludge, discharging excess heavy sludge after the first circulation reflux; 5) introducing the second mixed liquid formed by the light sludge and the sewage into the flocculent sludge biochemical reaction zone of the flocculent sludge section for a second biochemical reaction, and then performing solid-liquid separation in the sedimentation zone to obtain a clear liquid and residual light sludge, and discharging the clear liquid; 6) The residual light sludge is returned to the flocculent sludge biochemical reaction zone, and step 5) is repeated to discharge the excess light sludge after a second cycle of return.

10. The continuous flow aerobic granular sludge method for sewage treatment according to claim 9, characterized in that: Includes any one or more of the following conditions: 11) In step 1), the sewage is input into the mud-water contact area through the water inlet pipe; 12) In step 1), in the first separation, the sludge separation load of the sludge screen is 3 to 10 m / h; 21) In step 2), the first heavy sludge is refluxed to the water inlet end of the sludge-water contact zone through the first reflux pipe; 22) In step 2), the reaction time of the mud-water contact reaction is 1-3h; 23) In step 2), the mud-water contact reaction is carried out by stirring and mixing, and the stirring method is selected from one of mechanical stirring and air stirring; 31) In step 3), the first biochemical reaction is selected from one of an aerobic reaction or a combined reaction, the combined reaction includes an aerobic reaction and other reactions, and the other reactions are selected from at least one of an anaerobic reaction or an anoxic reaction; 32) In step 3), in the second separation, the sludge separation load of the sludge screen is 3 to 10 m / h; 41) In step 4), the excess heavy sludge is discharged through the first discharge pipe; 51) In step 5), the second biochemical reaction is selected from at least one of an aerobic reaction, an anaerobic reaction or an anoxic reaction; 52) In step 5), the clear liquid is discharged through the outlet pipe; 61) In step 6), the residual light sludge is refluxed to the water inlet end of the flocculent sludge biochemical reaction zone through the second reflux pipe or the third reflux pipe; 62) In step 6), the excess light sludge is discharged through the second discharge pipe.

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