Device for enhancing aerobic granular sludge cultivation by A-AGS method and aerobic granular sludge cultivation method

Abstract

The present invention discloses a device for enhancing the cultivation of aerobic granular sludge by the A-AGS method and an aerobic granular sludge cultivation method. The aerobic granular sludge cultivation device includes a control unit, as well as a water inlet tank, an anaerobic tank, and an aerobic granular sludge reaction tank connected in sequence; the control unit is respectively connected to the water inlet tank, the anaerobic tank, and the aerobic granular sludge reaction tank. The device of the present invention has a simple structure, is easy to operate and run, has a low cost, and has remarkable effects. The experimental device of the present invention can cultivate aerobic granular sludge with a median particle size greater than 220 μm within 30 days, the sludge has good sedimentation performance, the reactor has a high pollutant removal effect and maintains stable operation for a long time.

Description

Technical Field

[0001] The present invention belongs to the field of sewage treatment, and more specifically, relates to an A-AGS method for enhancing aerobic granular sludge cultivation and an aerobic granular sludge cultivation method. Background Art

[0002] Aerobic granular sludge is a granular microbial aggregate formed by the self-agglomeration and proliferation of microorganisms under special conditions. It has advantages that ordinary activated sludge methods cannot match: simultaneous nitrogen and phosphorus removal, dense structure, good sludge settling performance, high biomass, wide range of wastewater treatment, and strong impact resistance. The research on aerobic granular sludge technology began in the 1990s; in 2008, the world's first aerobic granular sludge technology was built. The municipal wastewater treatment demonstration project was put into operation in Gansbaai, South Africa, and then DHV We have promoted projects of different scales for technology brands. Compared with traditional sewage treatment processes, The advantages of the system are economical construction and operation costs, easy operation of the system and environmental benefits of sustainable development.

[0003] However, for municipal wastewater with low COD concentrations, the rapid formation and stable maintenance of granular sludge are relatively difficult, restricting the widespread application of aerobic granular sludge technology in municipal wastewater treatment. Therefore, based on the current intermittent flow treatment process, how to quickly achieve intermittent flow activated sludge granulation is of great development significance to the promotion and application of aerobic granular sludge technology in municipal wastewater treatment. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of difficulty in aerobic sludge granulation under low COD concentration and easy instability during long-term operation. It is committed to the promotion and application of aerobic granular sludge technology in the field of municipal sewage treatment and provides a device and method for enhancing aerobic granular sludge cultivation by the A-AGS method.

[0005] To achieve the above-mentioned object, the first aspect of the present invention provides an apparatus for enhancing aerobic granular sludge cultivation using the A-AGS method, the apparatus comprising a control unit, and a water inlet tank, an anaerobic tank, and an aerobic granular sludge reaction tank connected in sequence; the control unit is connected to the water inlet tank, the anaerobic tank, and the aerobic granular sludge reaction tank, respectively;

[0006] The water inlet tank is provided with a water inlet pump, and the water inlet pump is used to transport domestic sewage to the anaerobic tank;

[0007] The anaerobic tank contains activated sludge and is provided with an agitator and a submersible pump, and the submersible pump is used to transport the mixed liquid of activated sludge and domestic sewage to the aerobic granular sludge reaction tank;

[0008] An aeration device is provided at the bottom of the aerobic granular sludge reaction tank for aerating the mixture of activated sludge and domestic sewage.

[0009] A reflux pipe is provided between the aerobic granular sludge reaction tank and the anaerobic tank for refluxing the activated sludge at the bottom of the aerobic granular sludge reaction tank to the anaerobic tank.

[0010] The control unit controls the feed pump to transport domestic sewage to the anaerobic tank, controls the submersible pump to transport the mixture of activated sludge and domestic sewage to the aerobic granular sludge reaction tank, and controls the aeration device to conduct aeration.

[0011] According to the present invention, A-AGS in A-AGS refers to an anaerobic tank-aerobic granular sludge reaction tank.

[0012] According to the present invention, the submersible pump in the anaerobic tank is used to control the water inflow.

[0013] As a preferred solution, the feed pump and the water inlet of the anaerobic tank are connected through a first pipeline, and a water inlet solenoid valve is provided at one end of the first pipeline close to the anaerobic tank. The water outlet end of the feed pump is connected to the water inlet at the bottom of the anaerobic tank through the water inlet solenoid valve.

[0014] As a preferred solution, the submersible pump is connected to the water inlet of the aerobic granular sludge reaction tank through a second pipeline.

[0015] As a preferred solution, the aeration device is a microporous aeration disc, which is sequentially connected to an air pump and a control unit. As a further preferred solution, a glass rotameter is also provided between the microporous aeration disc and the air pump.

[0016] As a preferred solution, the aerobic granular sludge reaction tank is a columnar reaction tank operating intermittently.

[0017] As a preferred solution, sampling ports with different heights are provided on the side wall of the anaerobic tank for sampling the mixture of activated sludge and domestic sewage in the anaerobic tank.

[0018] As a preferred solution, the aerobic granular sludge reaction tank is provided with water outlets at different heights and a water outlet solenoid valve for controlling water discharge; the water outlet solenoid valve is connected to the water outlet through a water discharge pipe; the water outlet solenoid valve is connected to the control unit.

[0019] As a preferred solution, a reflux solenoid valve is provided on the reflux pipe, and the reflux solenoid valve is connected to the control unit for controlling sludge reflux.

[0020] According to the present invention, the control unit can control the operating conditions such as the influent water of the anaerobic tank, the influent water of the aerobic granular sludge reaction tank, sludge reflux, aeration, sedimentation, drainage, and idling, and is respectively connected to the power supplies of the influent water pump, the influent water solenoid valve, the submersible pump, the reflux solenoid valve, the effluent solenoid valve, and the air pump.

[0021] The second aspect of the present invention provides a method for culturing aerobic granular sludge in the device for enhancing aerobic granular sludge culture by the A-AGS method described above. The method includes:

[0022] 1) Place the activated sludge in the aerobic granular sludge reaction tank, mix it with domestic sewage, and successively perform aeration, sedimentation, drainage, and idling in the aerobic granular sludge reaction tank. Then, return a part of the activated sludge at the bottom of the aerobic granular sludge reaction tank to the anaerobic tank;

[0023] 2) The domestic sewage enters the anaerobic tank from the influent water tank through the influent water pump, and is fully mixed with the activated sludge in the anaerobic tank under the action of the stirrer to obtain a mixed solution;

[0024] 3) The mixed solution treated by the anaerobic tank enters the aerobic granular sludge reaction tank through the submersible pump. At the same time, a part of the activated sludge at the bottom of the aerobic granular sludge reaction tank is returned to the anaerobic tank, and is fully mixed with the domestic sewage from the influent water tank under the action of the stirrer to obtain a mixed solution;

[0025] 4) The aerobic granular sludge reaction tank successively performs aeration, sedimentation, drainage, and idling;

[0026] 5) Repeat steps 3) and 4) to obtain aerobic granular sludge;

[0027] 6) Repeat step 5);

[0028] The above steps optionally include step 5).

[0029] As a further preferred solution, the method for culturing aerobic granular sludge in the device for enhancing aerobic granular sludge culture by the A-AGS method described above includes:

[0030] 1) Place the activated sludge in the aerobic granular sludge reaction tank, mix it with domestic sewage, perform aeration in the aerobic granular sludge reaction tank for 150 - 210 min, then sediment for 5 - 10 min, then drain off the liquid accounting for 35 - 70% of the volume of the aerobic granular sludge reaction tank, idle for 10 - 20 min, and then return the activated sludge accounting for 5 - 30% of the volume of the aerobic granular sludge reaction tank at the bottom of the aerobic granular sludge reaction tank to the anaerobic tank;

[0031] 2) Domestic sewage enters the anaerobic tank from the inlet water tank through an inlet water pump, and is fully mixed with the activated sludge in the anaerobic tank under the action of a stirrer to obtain a mixed solution. The hydraulic retention time of domestic sewage in the anaerobic tank is 170 - 230 min;

[0032] 3) The mixed solution treated in the anaerobic tank enters the aerobic granular sludge reaction tank through a submersible pump, and the inlet water time is controlled to be 3 - 6 min; at the same time, 5 - 30% of the activated sludge relative to the volume of the aerobic granular sludge reaction tank at the bottom of the aerobic granular sludge reaction tank is refluxed to the anaerobic tank, and is fully mixed with the domestic sewage from the inlet water tank under the action of a stirrer to obtain a mixed solution;

[0033] 4) Aeration is carried out in the aerobic granular sludge reaction tank for 150 - 210 min, then precipitation is carried out for 5 - 10 min, and then 35 - 70% of the liquid relative to the volume of the aerobic granular sludge reaction tank is drained, and it is left idle for 10 - 20 min;

[0034] 5) Repeat steps 3) and 4) to obtain aerobic granular sludge;

[0035] 6) Repeat step 5);

[0036] The above steps optionally include step 5). <s

[0037] As a preferred scheme, the COD concentration of domestic sewage is 140 - 240 mg / L.

[0038] As a preferred scheme, the ammonia nitrogen concentration of domestic sewage is 20 - 35 mg / L.

[0039] As a preferred scheme, the TP concentration of domestic sewage is 3 - 5 mg / L.

[0040] Advantages of the present invention:

[0041] The present invention can cultivate aerobic granular sludge by inoculating flocculent sludge, create a substrate - poor / substrate - rich environment between the aerobic granular sludge reaction tank and the anaerobic tank by using a sludge reflux system, inhibit sludge bulking, and at the same time promote sludge granulation; the anaerobic environment in the anaerobic tank is beneficial to the enrichment of polyphosphate - accumulating bacteria with a slower growth rate, maintaining the stability of aerobic granular sludge; achieving the purpose of organic matter removal and nitrogen and phosphorus removal in a set of reactors, and realizing the stable operation of aerobic granular sludge technology under low COD (usually the COD concentration is higher than 400 mg / L) concentration conditions. The device of the present invention has a simple structure, is easy to operate and run, has a low cost and remarkable effects. The experimental device of the present invention can cultivate aerobic granular sludge with a median particle size greater than 220 μm within 30 d, the sludge has good sedimentation performance, and the reactor has a high pollutant removal effect and maintains stable operation for a long time.

[0042] Other features and advantages of the present invention will be described in detail in the following specific implementation section. Description of the Drawings

[0043] By describing the exemplary embodiments of the present invention in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present invention will become more apparent. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0044] Figure 1 Fig. shows a schematic structural diagram of the A-AGS method enhanced aerobic granular sludge cultivation device in Example 1 of the present invention.

[0045] Description of the reference numerals in the drawings:

[0046] 1 - water inlet tank, 2 - water inlet pump, 3 - water inlet solenoid valve, 4 - anaerobic tank, 5 - agitator, 6 - submersible pump, 7 - reflux solenoid valve, 8 - aerobic granular sludge reaction tank, 9 - microporous aeration disk, 10 - water outlet solenoid valve, 11 - glass rotameter, 12 - air pump, 13 - control unit. Specific Embodiments

[0047] The following will describe the preferred embodiments of the present invention in more detail. Although the following describes the preferred embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0048] Example 1

[0049] This example provides a device for enhancing the cultivation of aerobic granular sludge by the A-AGS method (as Figure 1 shown) and a method for cultivating aerobic granular sludge.

[0050] The A-AGS method enhanced aerobic granular sludge cultivation device includes a control unit 13, and a cylindrical water inlet tank 1, an anaerobic tank 4, and an aerobic granular sludge reaction tank 8 connected in sequence; the control unit 13 is respectively connected to the water inlet tank 1, the anaerobic tank 4, and the aerobic granular sludge reaction tank 8; a water inlet pump 2 is arranged in the water inlet tank 1 for transporting domestic sewage to the anaerobic tank 4; the anaerobic tank 4 is filled with activated sludge and is provided with a stirrer 5 and a submersible pump 6, and the submersible pump 6 is used for transporting the mixture of activated sludge and domestic sewage to the aerobic granular sludge reaction tank 8; the aerobic granular sludge reaction tank 8 is a columnar reaction tank operating intermittently; a microporous aeration disc 9 is arranged at the bottom of the aerobic granular sludge reaction tank 8 for aerating the mixture of activated sludge and domestic sewage, and is connected to a glass rotor flowmeter 11, an air pump 12, and the control unit 13 in sequence; a reflux pipe is arranged between the aerobic granular sludge reaction tank 8 and the anaerobic tank 4 for refluxing the activated sludge at the bottom of the aerobic granular sludge reaction tank 8 to the anaerobic tank 4; the control unit 13 controls the water inlet pump 2 to transport domestic sewage to the anaerobic tank 4, controls the submersible pump 6 to transport the mixture of activated sludge and domestic sewage to the aerobic granular sludge reaction tank 8, and controls the aeration device to aerate. The water inlet pump 2 and the water inlet of the anaerobic tank 4 are connected by a pipeline, and a water inlet solenoid valve 3 is arranged at one end of the pipeline close to the anaerobic tank 4; the submersible pump 6 is connected to the water inlet of the aerobic granular sludge reaction tank 8 by a pipeline; sampling ports with different heights are arranged on the side wall of the anaerobic tank 4 for sampling the mixture of activated sludge and domestic sewage in the anaerobic tank 4; the aerobic granular sludge reaction tank 8 is provided with water outlets at different heights and a water outlet solenoid valve 10 for controlling the water outlet, the water outlet solenoid valve 10 is connected to the water outlet through a water outlet pipe, and the water outlet solenoid valve 10 is connected to the control unit 13; the reflux pipe is provided with a reflux solenoid valve 7, and the reflux solenoid valve 7 is connected to the control unit 13.

[0051] The method for enhancing aerobic granular sludge cultivation by the A-AGS method is as follows:

[0052] 1) Place the activated sludge in the aerobic granular sludge reaction tank 8, mix it with domestic sewage, aerate it for 197 min through the microporous aeration disc 9 in the aerobic granular sludge reaction tank 8, then precipitate for 8 min, then drain 60% of the liquid relative to the volume of the aerobic granular sludge reaction tank, idle for 18 min, and then reflux 25% of the activated sludge at the bottom of the aerobic granular sludge reaction tank 8 relative to the volume of the aerobic granular sludge reaction tank 8 to the anaerobic tank 4;

[0053] 2) Domestic sewage enters the anaerobic tank 4 from the water inlet tank 1 through the water inlet pump 2, and is fully mixed with the activated sludge in the anaerobic tank 4 under the action of the stirrer 5 to obtain a mixed solution. The hydraulic retention time of the domestic sewage in the anaerobic tank 4 is 210 min;

[0054] 3) The mixed liquid treated by the anaerobic pond 4 enters the aerobic granular sludge reaction pond 8 through the submersible pump 6, and the water inlet time is controlled to be 5 min; 25% of the activated sludge at the bottom of the aerobic granular sludge reaction pond 8 relative to the volume of the aerobic granular sludge reaction pond is refluxed to the anaerobic pond 4, and is fully mixed with the domestic sewage from the water inlet tank 1 under the action of the agitator 5 to obtain a mixed liquid;

[0055] 4) Aeration is carried out in the aerobic granular sludge reaction pond 8 for 197 min, then precipitation is carried out for 8 min, and then 60% of the liquid relative to the volume of the aerobic granular sludge reaction pond 8 is drained, and it is left idle for 18 min;

[0056] 5) Repeat steps 3) and 4) to obtain aerobic granular sludge.

[0057] During the operation, the average values of the water quality indexes of domestic sewage COD, ammonia nitrogen and TP are 190 mg / L, 28 mg / L and 4 mg / L respectively. The operation mode of the reaction pond is intermittent operation. The inoculated activated sludge is the flocculent sludge in the aeration pond of a sewage treatment plant. The initial sludge particle size is 63 μm. After one month of operation, through the enhanced treatment of the anaerobic pond 4, the sludge particle size reaches 260 μm, and the flocculent sludge undergoes granulation to form aerobic granular sludge. When operating stably, the average values of the water quality indexes of the effluent COD, ammonia nitrogen and TP are 25 mg / L, 0.12 mg / L and 0.6 mg / L respectively.

[0058] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for culturing aerobic granular sludge, characterized in that, The device for culturing aerobic granular sludge by the A-AGS method adopted by the method includes a control unit, and a water inlet tank, an anaerobic tank and an aerobic granular sludge reaction tank connected in sequence; the control unit is respectively connected to the water inlet tank, the anaerobic tank and the aerobic granular sludge reaction tank; A water inlet pump is arranged in the water inlet tank, and the water inlet pump is used for conveying domestic sewage into the anaerobic tank; The anaerobic tank is filled with activated sludge and is provided with a stirrer and a submersible pump, and the submersible pump is used for conveying the mixed liquid of activated sludge and domestic sewage into the aerobic granular sludge reaction tank; An aeration device is arranged at the bottom of the aerobic granular sludge reaction tank for aerating the mixed liquid of activated sludge and domestic sewage; A reflux pipe is arranged between the aerobic granular sludge reaction tank and the anaerobic tank for refluxing the activated sludge at the bottom of the aerobic granular sludge reaction tank to the anaerobic tank; The control unit controls the water inlet pump to convey domestic sewage into the anaerobic tank, controls the submersible pump to convey the mixed liquid of activated sludge and domestic sewage into the aerobic granular sludge reaction tank, and controls the aeration device to perform aeration; The method includes: 1) Placing the activated sludge in the aerobic granular sludge reaction tank, mixing it with domestic sewage, aerating in the aerobic granular sludge reaction tank for 150 - 210 min, then settling for 5 - 10 min, then discharging the liquid accounting for 35 - 70% of the volume of the aerobic granular sludge reaction tank, idling for 10 - 20 min, and then refluxing the activated sludge accounting for 5 - 30% of the volume of the aerobic granular sludge reaction tank at the bottom of the aerobic granular sludge reaction tank to the anaerobic tank; 2) Domestic sewage enters the anaerobic tank from the water inlet tank through the water inlet pump, and is fully mixed with the activated sludge in the anaerobic tank under the action of the stirrer to obtain a mixed liquid, and the hydraulic retention time of the domestic sewage in the anaerobic tank is 170 - 230 min; 3) The mixed liquid treated by the anaerobic tank enters the aerobic granular sludge reaction tank through the submersible pump, and the water inlet time is controlled for 3 - 6 min; at the same time, the activated sludge accounting for 5 - 30% of the volume of the aerobic granular sludge reaction tank at the bottom of the aerobic granular sludge reaction tank is refluxed to the anaerobic tank, and is fully mixed with the domestic sewage from the water inlet tank under the action of the stirrer to obtain a mixed liquid; 4) Aerating in the aerobic granular sludge reaction tank for 150 - 210 min, then settling for 5 - 10 min, then discharging the liquid accounting for 35 - 70% of the volume of the aerobic granular sludge reaction tank, and idling for 10 - 20 min; 5) Repeating steps 3) and 4) to obtain aerobic granular sludge; The COD concentration of the domestic sewage is 140 - 240 mg / L; The ammonia nitrogen concentration of the domestic sewage is 20 - 35 mg / L; The TP concentration of the domestic sewage is 3 - 5 mg / L.

2. According to the method for culturing aerobic granular sludge according to claim 1, wherein, The water inlet pump and the water inlet of the anaerobic tank are connected through a first pipeline, and a water inlet solenoid valve is arranged at one end of the first pipeline close to the anaerobic tank.

3. According to the method for culturing aerobic granular sludge according to claim 1, wherein, The submersible pump is connected to the water inlet of the aerobic granular sludge reaction tank through a second pipeline.

4. The aerobic granular sludge cultivation method according to claim 1, wherein, The aeration device is a microporous aeration disc, which is sequentially connected to an air pump and a control unit.

5. The aerobic granular sludge cultivation method according to claim 1, wherein, The aerobic granular sludge reaction tank is a columnar reaction tank operating intermittently.

6. The aerobic granular sludge cultivation method according to claim 1, wherein, Sampling ports with different heights are provided on the side wall of the anaerobic tank for sampling the mixed liquid of activated sludge and domestic sewage in the anaerobic tank.

7. The aerobic granular sludge cultivation method according to claim 1, wherein, The aerobic granular sludge reaction tank is provided with water outlets at different heights and a water outlet solenoid valve for controlling water discharge; The water outlet solenoid valve is connected to the water outlet through a water outlet pipe; The water outlet solenoid valve is connected to the control unit.

8. The aerobic granular sludge cultivation method according to claim 1, wherein, A reflux solenoid valve is provided on the reflux pipe, and the reflux solenoid valve is connected to the control unit.

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