Low-carbon sewage treatment system

Abstract

The invention discloses a low-carbon sewage treatment system. The low-carbon sewage treatment system comprises a water inlet system for conveying sewage; a filler is arranged in each tank, an aeration device is arranged in each tank, and the reaction tanks are used for receiving sewage conveyed by the water inlet system and treating the sewage; the water inlet end of the secondary sedimentation tank is communicated with the water outlet end of the reaction tank, and the secondary sedimentation tank is used for carrying out mud-water separation on the treated water body and returning part of settled sludge to the reaction tank; and the cyclone is communicated with the sludge discharge end of the secondary sedimentation tank and is used for receiving sludge settled in the secondary sedimentation tank, screening and separating the sludge and recycling the sludge to the reaction tank or discharging the sludge. According to the system, the treatment process can be adjusted in time when the quality and quantity of inlet water change, and the running state of the system can be adjusted according to the quantity of sewage and the pollutant concentration; internal reflux is not needed, so that energy consumption is reduced; the sludge can be recycled after being screened, and the activity and the concentration of the sludge in the reaction tank can be adjusted, so that different sewage treatment requirements can be met.

Description

Technical Field

[0001] The invention relates to a low-carbon sewage treatment system, belonging to the technical field of sewage treatment. Background Art

[0002] With the rapid development of social economy, the amount of sewage treatment is increasing, and various sewage treatment equipment is increasing. In order to meet the needs of different sewage treatment, the process of sewage treatment equipment often needs to be repeatedly designed according to the sewage quality. Once the sewage treatment process is determined, when the sewage quality changes, it is difficult to change the treatment process to cope with the change of sewage quality, which often causes the effluent water quality to fluctuate or exceed the standard. In addition, the current sewage treatment process is mainly based on biological methods, relying on the anaerobic, anoxic and aerobic reactions of microorganisms to achieve the removal of organic matter, nitrogen and phosphorus in various sewage. However, the traditional nitrification / denitrification sewage denitrification process requires a large flow of internal recirculation, high aeration energy consumption, and a large amount of residual sludge produced by the traditional sewage treatment system, which cannot effectively adjust the sludge properties to cope with changes in sewage quality and quantity. Therefore, in view of the problems existing in the current sewage treatment process, how to reduce the repeated process design in the early stage of sewage treatment, improve the production efficiency of sewage treatment equipment, improve the stability of the sewage treatment system, and reduce the energy consumption of the sewage treatment process is a new direction for the development of sewage treatment in the future. Summary of the invention

[0003] The purpose of the present invention is to provide a low-carbon sewage treatment system, which can adjust the process of the reaction tank in time when the inlet water quality changes to ensure that the effluent water quality meets the standard. It can adjust the system operation state in time when the sewage volume is small or the pollutant concentration is low to reduce the operating energy consumption; in addition, no internal reflux is required, saving energy consumption; at the same time, the sludge discharged from the secondary sedimentation tank is reused after screening by a cyclone, and the activity and sludge concentration of the reaction tank sludge can be adjusted to meet different sewage treatment needs.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A low-carbon sewage treatment system, comprising:

[0006] Inlet system for conveying sewage;

[0007] Several reaction tanks connected in sequence, each of which is filled with fillers and equipped with aeration devices, are used to receive sewage transported through the water inlet system and treat the sewage;

[0008] The secondary sedimentation tank, whose water inlet is connected to the water outlet of the reaction tank, is used to separate the mud and water in the treated water and return part of the settled sludge to the reaction tank;

[0009] The cyclone is connected to the sludge discharge end of the secondary sedimentation tank and is used to receive the sludge settled in the secondary sedimentation tank and screen and separate it before recycling it to the reaction tank or discharging it.

[0010] Preferably, the water inlet system includes a water inlet main pipe and a plurality of water inlet branch pipes, each of the water inlet branch pipes is respectively connected to a corresponding reaction tank, and a water inlet flow regulating valve is provided on the water inlet branch pipe.

[0011] Preferably, the number of reaction cells is at least 3.

[0012] Preferably, the filling amount of the filler in each reaction cell is 30-60%.

[0013] Preferably, the aeration device includes an aeration tube and an aeration head arranged on the aeration tube, and each aeration tube is connected to an external air supply fan through a pipeline.

[0014] Preferably, a flow promoter is installed in each reaction tank for applying a thrust to make the water flow toward the water inlet of the reaction tank.

[0015] Preferably, a sludge return pump is provided at the bottom of the secondary sedimentation tank, the sludge return pump is connected with the reaction tank and the inlet of the cyclone through a pipeline, and a sludge flow regulating valve is installed on the corresponding pipeline.

[0016] Preferably, the sludge return ratio between the secondary sedimentation tank and the reaction tank is 50-150%.

[0017] Preferably, the top mud discharge port and the bottom mud discharge port of the cyclone are both connected to the reaction tank through pipelines, and an upper outlet sludge recycling valve and a lower outlet sludge recycling valve are respectively provided on the corresponding pipelines.

[0018] Preferably, sludge discharge pipes are provided at the top and bottom sludge discharge ports of the cyclone, and upper and lower outlet sludge discharge valves and lower outlet sludge discharge valves are provided on the corresponding sludge discharge pipes.

[0019] The beneficial effects of the present invention are:

[0020] 1. The process of the biochemical reaction zone is variable. Therefore, when the influent water quality changes, the process of the reaction pool can be adjusted in time to ensure that the effluent water quality meets the standard.

[0021] 2. When the amount of sewage is small or the concentration of pollutants is low, the system operation status can be adjusted in time to reduce operating energy consumption;

[0022] 3. No need for internal reflux, saving energy;

[0023] 4. The sludge discharged from the secondary sedimentation tank is screened by a cyclone, which can adjust the activity and sludge concentration of the reaction tank sludge to meet different sewage treatment needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the sewage treatment system.

[0025] The main reference numerals in the figure have the following meanings:

[0026] 1. Water inlet system, 2. Reaction tank, 3. Secondary sedimentation tank, 4. Cyclone, 5. Water inlet main pipe, 6. Water inlet branch pipe, 7. Water inlet flow regulating valve, 8. Filler, 9. Aeration device, 10. Aeration pipe, 11. Aeration head, 12. Fan, 13. Flow pusher, 14. Sludge return pump, 15. Sludge flow regulating valve, 16. Upper outlet sludge reuse valve, 17. Lower outlet sludge reuse valve, 18. Upper outlet sludge discharge valve, 19. Lower outlet sludge discharge valve. DETAILED DESCRIPTION

[0027] The low-carbon sewage treatment systems used in the following embodiments all include a water inlet system 1 , a plurality of reaction tanks 2 , a secondary sedimentation tank 3 and a cyclone 4 .

[0028] The water inlet system 1 is used to transport sewage, and includes a main water inlet pipe 5 and a plurality of water inlet branches 6 . Each water inlet branch 6 is connected to a corresponding reaction tank 2 , and a water inlet flow regulating valve 7 is provided on the water inlet branch 6 .

[0029] Several reaction tanks 2 are connected in sequence, each of which is provided with fillers 8 and aeration devices 9 for receiving sewage transported by the water inlet system 1 and treating the sewage.

[0030] The filler 8 is an MBBR suspended filler 8, which adopts a conventional MBBR carrier, has a diameter of 25 cm, 19 to 39 holes, and a thickness of 1 cm. The filling amount of the filler 8 in each reaction tank 2 is 30-60%. The aeration device 9 includes an aeration pipe 10 and an aeration head 11 arranged on the aeration pipe 10. Each aeration pipe 10 is connected to an external air supply fan 12 through a pipeline. At the same time, a flow pusher 13 is installed in each reaction tank 2 to apply a thrust to make the water flow flow toward the water inlet of the reaction tank 2.

[0031] The reaction tank 2 has two states. When the aeration is turned on and the flow pusher 13 is turned off, the reaction tank 2 is an aerobic tank and performs an aerobic reaction. When the aeration system is turned off and the flow pusher 13 is turned on, the reaction tank 2 is an anaerobic tank or an anoxic tank and performs an anaerobic or anoxic reaction. Therefore, the reaction tank 2 (1 to n) can be used for both anaerobic / anoxic reactions and aerobic reactions.

[0032] The water inlet of the secondary sedimentation tank 3 is connected to the water outlet of the reaction tank 2, and is used to separate mud and water from the treated water. A sludge return pump 14 is provided at the bottom of the secondary sedimentation tank 3. The sludge return pump 14 is connected to the inlet of the reaction tank 2 and the cyclone 4 through a pipeline, and a sludge flow regulating valve 15 is installed on the corresponding pipeline. The water after mud and water separation is discharged to the next treatment process, and part of the settled sludge is returned to the reaction tank 2, and the remaining sludge is discharged to the cyclone 4. The sludge return ratio between the secondary sedimentation tank 3 and the reaction tank 2 is 50-100%.

[0033] The cyclone 4 is connected to the sludge discharge end of the secondary sedimentation tank 3, and the top sludge discharge port (upper outlet) and the bottom sludge discharge port (lower outlet) are both connected to the reaction tank 2 through pipelines, and the upper outlet sludge recycling valve 16 and the lower outlet sludge recycling valve 17 are respectively provided on the corresponding pipelines. The top sludge discharge port and the bottom sludge discharge port of the cyclone 4 are also provided with sludge external discharge pipes, and the upper outlet sludge external discharge valve 18 and the lower outlet sludge external discharge valve 19 are correspondingly provided on the corresponding sludge external discharge pipes. The cyclone 4 is used to receive the sludge settled in the secondary sedimentation tank 3 and centrifugally separate it, and then rotate it back to the reaction tank 2 or discharge it.

[0034] Example 1

[0035] The number of reaction tanks 2 in the sewage treatment system is 5, and has the following 4 working states;

[0036] Process state 1: The aeration device 9 of the 1#, 2#, 3#, 4#, and 5# reaction tanks 2 is turned on, and the flow promoter 13 is turned off. The reaction tanks 2 are all aerobic tanks, and the sewage treatment system is an aerobic process; it can be used for sewage treatment containing only COD.

[0037] Process state 2: The flow promoter 13 of the 1# and 2# reaction tanks 2 is turned on, and the aeration device 9 is turned off, which is an anoxic tank; the aeration device 9 of the 3#, 4#, and 5# reaction tanks 2 is turned on, and the flow promoter 13 is turned off, which is an aerobic tank. The sewage treatment system is an AO process, which can be used for sewage treatment containing COD and ammonia nitrogen.

[0038] Process state 3: The flow promoter 13 of 1#, 2# and 3# reaction tanks 2 is turned on, and the aeration device 9 is turned off. The 1# reaction tank 2 is an anaerobic tank, and the 2# and 3# reaction tanks 2 are anoxic tanks; the aeration device 9 of 4# and 5# reaction tanks 2 is turned on, and the flow promoter 13 is turned off, and they are aerobic tanks. The sewage treatment system is an A2O process, which can be used for sewage treatment containing COD, ammonia nitrogen and total phosphorus.

[0039] Process state 4: the flow promoter 13 is turned on for 1#, 2# and 4# reaction tanks 2, and the aeration device 9 is turned off. The 1# reaction tank 2 is an anaerobic tank, and the 2# and 4# reaction tanks 2 are anoxic tanks. The aeration device 9 is turned on for 3# and 5# reaction tanks 2, and the flow promoter 13 is turned off, and they are aerobic tanks. The sewage treatment system is an AAOAO process, which can be used for sewage treatment with high total nitrogen content.

[0040] Sewage enters the anaerobic / anoxic reaction tank 2 through the water inlet branch pipe 6, flows through each reaction tank 2 in turn, and then enters the secondary sedimentation tank 3 for mud and water separation. After sedimentation, the water flows out and enters the next treatment process. Part of the sludge precipitated in the secondary sedimentation tank 3 flows back to the anaerobic tank through the sludge return pipe, and part enters the cyclone 4. The sludge is centrifugally screened and separated by the cyclone 4, and part of the sludge with more organic matter is discharged from the top sludge discharge port, and part of the sludge with more inorganic matter is discharged from the bottom sludge discharge port. When the reaction tank 2 needs to improve the sludge settling performance, the sludge discharged from the bottom sludge discharge port of the cyclone 4 flows back to the reaction tank 2, and the sludge discharged from the top sludge discharge port is discharged from the sludge external discharge pipe; when the reaction tank 2 needs to reduce the inorganic components of the sludge and increase the sludge activity, the sludge discharged from the top sludge discharge port of the cyclone 4 flows back to the reaction tank 2, and the sludge discharged from the bottom sludge discharge port is discharged from the sludge external discharge pipe.

[0041] Example 2

[0042] The sewage is domestic sewage, COD is 200-300mg / L, ammonia nitrogen is 10-20mg / L, total phosphorus is 2-3mg / L, total nitrogen is 20-30mg / L, the number of reaction pools 2 in the sewage treatment system is 6, the effective volume of each reaction pool 2 is 3m3, the MBBR carrier filling volume is 30%, and the sludge return is 100%. When the inflow is less than 1m 3 / h, when the water volume is small, the process state of reaction tank 2 is AOAAAO, and sewage enters from reaction tanks 21 and 3. At this time, the system can reduce aeration energy consumption as much as possible while meeting the sewage treatment needs; when the water volume is 1-1.5m 3 / h, the process state of reaction tank 2 is adjusted to AOAOAO, which can enhance the efficiency of denitrification treatment in the sewage treatment system; when the water volume is 1.5-2.5m 3 / h, the process state of the reaction tank 2 is AOAOAO. The sludge concentration in the reaction tank 2 can be increased by opening the cyclone 4 to reuse the sludge discharged from the bottom sludge outlet to increase the sewage treatment load of the system.

[0043] Example 3

[0044] The sewage is industrial wastewater, COD is 500-1000mg / L, ammonia nitrogen is 5-10mg / L, total nitrogen is 10-15mg / L, the number of reactors 2 in the sewage treatment system is 3, and the process state of reactor 2 is AOO process. When the sewage quality changes, COD is 500-1000mg / L, ammonia nitrogen is 10-20mg / L, total nitrogen is 15-20mg / L, and the process state of reactor 2 is AOA process, the cyclone 4 is opened to reuse the sludge discharged from the bottom sludge outlet, and the sludge concentration in reactor 2 is increased to increase the sewage treatment load of the system and strengthen the denitrification demand of sewage.

[0045] Example 4

[0046] The sewage is industrial wastewater. The sewage treatment system is impacted, the sludge is partially disintegrated, and the ammonia nitrogen in the effluent increases. The cyclone 4 is turned on to reuse the sludge flowing out of the top sludge outlet to degrade the inorganic component content of the sludge and increase the content of organic bacterial components such as COD degrading bacteria and nitrifying bacteria in the sludge in the reaction tank 2 to improve the sludge activity of the system and strengthen the denitrification demand of the sewage.

[0047] The above is only a preferred implementation of the patent of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the patent of the present invention. These improvements and modifications should also be regarded as the scope of protection of the patent of the present invention.

Claims

1. A low-carbon sewage treatment system, characterized in that: include: Inlet system for conveying sewage; Several reaction tanks connected in sequence, each of which is filled with fillers and equipped with aeration devices, are used to receive sewage transported through the water inlet system and treat the sewage; The secondary sedimentation tank, whose water inlet is connected to the water outlet of the reaction tank, is used to separate the mud and water from the treated water and return part of the settled sludge to the reaction tank; The cyclone is connected to the sludge discharge end of the secondary sedimentation tank and is used to receive the sludge settled in the secondary sedimentation tank and screen and separate it before recycling it to the reaction tank or discharging it.

2. The low-carbon sewage treatment system according to claim 1, characterized in that: The water inlet system comprises a water inlet main pipe and a plurality of water inlet branch pipes, each of which is connected to a corresponding reaction tank, and a water inlet flow regulating valve is arranged on the water inlet branch pipe.

3. The low-carbon sewage treatment system according to claim 1, characterized in that: The number of reaction cells is at least 3.

4. The low-carbon sewage treatment system according to claim 1, characterized in that: The filling amount of the filler in each reaction cell is 30-60%.

5. The low-carbon sewage treatment system according to claim 1, characterized in that: The aeration device comprises an aeration pipe and an aeration head arranged on the aeration pipe, and each aeration pipe is connected to an external air supply fan through a pipeline.

6. The low-carbon sewage treatment system according to claim 1, characterized in that: A flow promoter is installed in each reaction tank to apply a thrust to make the water flow toward the water inlet of the reaction tank.

7. The low-carbon sewage treatment system according to claim 1, characterized in that: A sludge return pump is arranged at the bottom of the secondary sedimentation tank, and the sludge return pump is connected with the reaction tank and the inlet of the cyclone through a pipeline, and a sludge flow regulating valve is installed on the corresponding pipeline.

8. The low-carbon sewage treatment system according to claim 1, characterized in that: The sludge return ratio between the secondary sedimentation tank and the reaction tank is 50-150%.

9. The low-carbon sewage treatment system according to claim 1, characterized in that: The top mud discharge port and the bottom mud discharge port of the cyclone are both connected to the reaction tank through pipelines, and an upper outlet sludge recycling valve and a lower outlet sludge recycling valve are respectively arranged on the corresponding pipelines.

10. The low-carbon sewage treatment system according to claim 9, characterized in that: The top and bottom mud discharge ports of the cyclone are respectively provided with mud discharge pipes, and upper and lower mud discharge valves are provided on the corresponding mud discharge pipes.

Images