A wastewater treatment using a mabr coupled with a mbr and a method of use thereof

Abstract

The present application relates to a kind of MABR coupling MBR sewage treatment and its use method, it is related to water treatment technical field, the present application maintains the pretreatment system of original sewage treatment process, places MABR membrane treatment unit in the latter half of anaerobic zone, anoxic zone, front end of aerobic zone, MBR membrane component constructs sedimentation filtration system;Carbon and nitrogen in sewage are well adsorbed and degraded using MABR membrane system, and MABR biofilm has simultaneous nitrification and denitrification effect, nitrogen removal effect is remarkable, nitrogen is removed better under the condition of same carbon nitrogen ratio, carbon source is saved, MBR has good sludge-water separation effect, and the operating parameters of control system are regulated and optimized.Utilizing, under the condition that water quality index of sewage effluent is unchanged, realize the capacity increase of inlet flow, under the condition that the same inlet flow is unchanged, realize the improvement of effluent quality.The present application MABR coupling MBR sewage treatment and its use method have the advantages of good pollutant removal effect, saving external carbon source addition, saving land occupation, low energy consumption and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sewage treatment, and relates to a sewage treatment system combining MABR and MBR and a use method thereof. BACKGROUND

[0002] At present, with the continuous development of urbanization and the improvement of people's living standards, the urban population and water consumption gradually increase, and the sewage discharge of towns also increases. The town sewage treatment plant is a key link for end control of water pollution and long-term control of water environment, and the most core treatment structure in the sewage treatment plant is the biochemical treatment unit. In order to better control pollutants and reduce pollution to the water environment, stricter discharge water quality index requirements are put forward for the effluent of the town sewage treatment plant. Therefore, more and more town sewage treatment plant upgrading and efficiency improvement projects are proposed in most cities in China, especially the effluent index requirement of nitrogen is higher and higher. In order to improve the denitrification efficiency, external carbon source is needed, which increases the cost and also increases the sludge production, thereby increasing the burden of subsequent treatment processes.

[0003] The application of membrane aeration biological membrane reactor (MABR) technology in town sewage treatment upgrading and efficiency improvement projects is gradually increasing. The low-carbon denitrification technology of MABR technology has been well applied, but the parameter regulation and control of MABR technology needs to be further strengthened. The biological membrane reactor (MBR) technology replaces the traditional biological treatment technology end secondary sedimentation tank with membrane components, maintains high active sludge concentration in the biological reactor, improves the organic load of biological treatment, thereby reducing the land occupation area of sewage treatment facilities, and reduces the amount of residual sludge by maintaining low sludge load.

[0004] Both MABR technology and MBR technology have their own unique advantages, but the problem of membrane clogging and membrane pollution needs to be considered due to high suspended solids concentration in the use process of MBR technology. In the use process of MABR technology as a biological treatment unit, the amount of sludge produced is much less than that of the conventional biological treatment method, which greatly reduces the sludge content in the MBR tank body. However, the system coordination and regulation method during the combined use of the two technologies is particularly important. Therefore, a sewage treatment system combining MABR and MBR is researched and a regulation method is obtained, so as to realize the coordination of the combination of the two technologies and realize the efficient treatment of town sewage. SUMMARY

[0005] The application is a biological treatment system constructed by MABR membrane treatment unit, which maintains the pretreatment system of the original wastewater treatment process, places the MABR membrane treatment unit in the latter half of the anaerobic zone, the anoxic zone and the front end of the aerobic zone, constructs a sedimentation and filtration system by using the MBR membrane assembly, omits the secondary sedimentation tank, reduces the addition of external carbon source and sludge production by establishing the MABR and MBR linkage regulation system, thereby reducing the sludge content of the MBR system, realizing efficient nitrogen removal treatment of wastewater treatment, improving the effluent indicators of the municipal wastewater treatment plant and increasing the amount of treated wastewater, and completing the quality improvement and efficiency increase of the municipal wastewater treatment plant.

[0006] The specific technical solutions are as follows:

[0007] A wastewater treatment method of MABR coupled with MBR, characterized in that the specific steps are as follows:

[0008] (1) Constructing a primary MABR anaerobic treatment system: implanting the MABR filler membrane treatment unit into the latter half of the original anaerobic zone, stopping water feeding after the completion of water feeding of the tank body, starting the air supply system, stopping aeration for 24 hours after aeration for 24 hours, gradually resuming aeration and increasing the flow by 15%-20% per day for gradient water feeding, feeding water at normal flow after 5-7 days, controlling the dissolved oxygen to be less than 0.2 mg / L, and gradually forming an anoxic / anaerobic biofilm structure on the outer surface of the MABR membrane wire from inside to outside, forming an anaerobic biofilm structure of the filler, and completing the construction of the MABR anaerobic treatment system with anaerobic treatment and MABR anoxic treatment;

[0009] (2) Constructing a secondary MABR anoxic treatment system: mainly composed of a MABR membrane treatment unit, a pusher, an air supply system and a monitoring system, implanting the MABR membrane treatment unit into the original anoxic zone, dividing the original anoxic zone into two zones, forming single-zone mixed flow, and forming push flow in series, the pusher is arranged at the head of the second zone, the tank body receives the effluent of the primary MABR anaerobic treatment system, the air supply system is started, the aeration amount is reduced after aeration for 24 hours, the dissolved oxygen content of the anoxic zone tank body is maintained at 0.2-0.5 mg / L, water is fed at normal flow after 5-7 days, the outer surface of the MABR membrane wire is gradually formed from inside to outside to form an aerobic / anoxic biofilm structure, carbon and nitrogen pollutants are degraded and removed, and the construction of the MABR anoxic treatment system with anoxic treatment and MABR aerobic treatment is completed;

[0010] (3) Constructing MABR aerobic treatment system: mainly composed of MABR membrane treatment unit, gas supply system and monitoring system, implanting MABR membrane treatment unit into the front end of the original aerobic zone, using a partition to divide the original aerobic zone into two zones, the front half is MABR aerobic zone, and the back half maintains the original aerobic zone, the gas supply system continuously supplies gas, the pool body receives the effluent of the secondary MABR anoxic treatment system, the gas supply system is continuously running, the dissolved oxygen content of the aerobic zone pool body is maintained at 0.5-1.5mg / L, after 5-7 days, the normal flow is fed, and the low aerobic biofilm structure is gradually formed on the outer surface of the MABR membrane filament from inside to outside, the carbon and nitrogen pollutants are degraded and removed, and the MABR aerobic treatment system is constructed;

[0011] (4) Constructing MBR filtration and sedimentation system: mainly composed of MBR tank, MBR treatment unit, pump set, MBR aeration system, gas supply system and monitoring system, the MBR treatment unit is arranged in the MBR tank, the MBR aeration system is arranged at the bottom of the MBR tank, the sludge in the MBR tank comes from the aerobic treatment system, and the sludge concentration is maintained at 6000mg / L or above;

[0012] (5) System operation: after the completion of the construction of each system, the hydraulic retention time is adjusted, the data feedback from the monitoring system in each pool body is fed back to the central control system, the parameters of the gas supply pressure, dissolved oxygen content, hydraulic retention time, MBR sludge concentration of each system are adjusted through the central control system, the sewage treatment system is optimized, and the discharge standard is reached;

[0013] The hydraulic retention time of the primary MABR anaerobic treatment system is 1-2h;

[0014] The hydraulic retention time of the secondary MABR anoxic treatment system is 5-8h;

[0015] The hydraulic retention time of the MABR aerobic treatment system is 8-12h, and the filling ratio of the MABR membrane treatment unit is less than 1 / 3;

[0016] The MABR good treatment system is provided with mixed liquid reflux, the end of the aerobic zone without MABR membrane treatment unit is refluxed to the front end of the secondary MABR anoxic treatment system, and the reflux ratio is 100%-300%;

[0017] The gas supply system mainly includes gas supply equipment, gas supply pipeline and valve, the gas supply pipeline is connected with the MABR filler membrane treatment unit, the MABR membrane treatment unit and the MBR aeration system of each pool body, and gas is supplied to each system through the gas supply pipeline;

[0018] The monitoring system mainly monitors the dissolved oxygen, temperature, gas supply pressure, chemical oxygen demand, ammonia nitrogen, total nitrogen and total phosphorus.

[0019] Further, the MABR packing film treatment unit is mainly composed of a MABR membrane assembly, a membrane rack, a curtain packing, a gas connecting pipe and a valve, the number of MABR packing film treatment units in the primary MABR anaerobic treatment system is designed to be 2 or more.

[0020] Further, the MABR packing film treatment unit is mainly composed of a MABR membrane assembly, a membrane rack, a curtain packing, a gas connecting pipe and a valve, the number of MABR packing film treatment units in the primary MABR anaerobic treatment system is designed to be 2 or more.

[0021] The MABR coupled MBR sewage treatment and use method has the advantages of good pollutant removal effect, saving of external carbon source addition, saving of land occupation, low energy consumption and the like. DETAILED DESCRIPTION

[0022] The application is further described in combination with examples, and the comparative examples are implemented:

[0023] A certain urban sewage treatment plant has a treatment scale of 25,000 m 3 / d, the influent water quality is as follows: COD 150-450 mg / L, ammonia nitrogen 20-40 mg / L, total nitrogen 20-50 mg / L, and total phosphorus 1-4 mg / L, the effluent water quality index before quality improvement and efficiency enhancement meets the first level A standard of the Urban Sewage Treatment Plant Pollutant Discharge Standard, the main water quality indexes are COD ≤ 50 mg / L, ammonia nitrogen ≤ 5(8) mg / L, total nitrogen ≤ 15 mg / L, and total phosphorus ≤ 0.5 mg / L; after quality improvement and efficiency enhancement, when the treatment water quantity is unchanged in dry season, the main water quality indexes meet the Class IV standard of the Surface Water Environmental Quality Standard, wherein COD ≤ 30 mg / L, ammonia nitrogen ≤ 1.5 mg / L, total nitrogen ≤ 10 mg / L, and total phosphorus ≤ 0.3 mg / L, and in rainy season, the first level A standard of the Urban Sewage Treatment Plant Pollutant Discharge Standard is met while the treatment water quantity is increased to 30,000 m 3 / d.

[0024] The original process system adopts AAO process. In order to achieve the standard of total nitrogen, the input amount of external carbon source is relatively large. According to the project situation, the MABR technology is used to transform the biological treatment unit. The original half of the treatment capacity of the secondary sedimentation tank is retained, and the other is replaced by the MBR tank. The phosphorus removal device is added for deep treatment. In the dry season, the main water quality indicators can reach the standard of Class IV of the Environmental Quality Standard for Surface Water, in which COD is less than or equal to 30 mg / L, ammonia nitrogen is less than or equal to 1.5 mg / L, total nitrogen is less than or equal to 10 mg / L, and total phosphorus is less than or equal to 0.3 mg / L. The implementation scheme of the transformation process is as follows:

[0025] (1) Start to implant 10 groups of MABR filler membrane treatment units at the rear 1 / 3 of the anaerobic tank. Replace the original anoxic tank with a two-stage MABR anoxic treatment system. A total of 220 groups of MABR membrane treatment units are arranged. Set 60 groups of MABR membrane treatment units at the front 1 / 3 of the aerobic tank. Change part of the original secondary sedimentation tank into an MBR tank. Maintain the original gas supply system. Add a primary MABR anaerobic treatment system gas supply pipeline and an MBR tank gas supply pipeline. Maintain the original gas supply equipment without adding new ones. The equipment can be frequency-adjusted.

[0026] (2) During the biofilm formation and domestication period, the primary MABR anaerobic treatment system and the secondary MABR anoxic treatment system are synchronized. Stop feeding after the tank body is fully fed. Turn on the gas supply system. Stop aeration for 24 hours after aeration for 24 hours. Gradually restore aeration and increase the flow rate by 15%-20% per day. After 5-7 days, feed at normal flow rate. The dissolved oxygen content in the primary MABR anaerobic treatment system is less than 0.2 mg / L. The dissolved oxygen content in the secondary MABR anoxic treatment system is 0.2-0.5 mg / L. The MABR aerobic treatment system starts biofilm formation and domestication one day later than the primary MABR anaerobic treatment system and the secondary MABR anoxic treatment system. Use a partition to divide the original aerobic zone into two zones. The front half is the MABR aerobic zone, and the back half maintains the original aerobic zone. The gas supply system continues to supply gas. The tank body receives the effluent from the secondary MABR anoxic treatment system. Turn on the gas supply system and continue to operate. Maintain the dissolved oxygen content in the aerobic zone tank body at 0.5-1.5 mg / L. After 5-7 days, feed at normal flow rate. When the MABR membrane filament outer surface of the primary MABR anaerobic treatment system forms an anoxic / anaerobic biofilm structure from inside to outside, the filler forms an anaerobic biofilm structure, the MABR membrane filament outer surface of the secondary MABR anoxic treatment system forms an aerobic / anoxic biofilm structure from inside to outside, and the MABR membrane filament outer surface of the MABR aerobic treatment system forms an aerobic / anoxic biofilm structure from inside to outside, it indicates that each system is completed.

[0027] (3) MBR filtration and sedimentation system: the original secondary sedimentation tank is partially transformed into MBR system, which mainly consists of MBR tank, MBR treatment unit, pump set, MBR aeration system, gas supply system and monitoring system, the MBR treatment unit is arranged in the MBR tank, the MBR aeration system is arranged at the bottom of the MBR tank, the sludge in the MBR tank comes from the aerobic treatment system, and the sludge concentration is maintained at 6000 mg / L or above;

[0028] (4) Monitoring system: the original monitoring system of each system is maintained, and the monitoring indexes of dissolved oxygen, temperature and gas supply pressure of the MBR tank are added, and each index data can be fed back to the central control system;

[0029] (5) Each treatment unit: the gas supply system mainly includes gas supply equipment, gas supply pipeline and valve, the gas supply pipeline is connected with the MABR filler membrane treatment unit, MABR membrane treatment unit and MBR aeration system of each tank body, and gas is supplied to each system through the gas supply pipeline; the MABR filler membrane treatment unit mainly consists of MABR membrane assembly, membrane rack, curtain filler, gas connection pipe and valve; the MABR membrane treatment unit mainly consists of MABR membrane assembly, membrane rack, gas connection pipe and valve;

[0030] (6) System operation: after the completion of each system, in the initial operation stage, the hydraulic retention time of the first-stage MABR anaerobic treatment system is 2h, the hydraulic retention time of the second-stage MABR anoxic treatment system is 8h, the hydraulic retention time of the ABR aerobic treatment system is 12h, the MABR good treatment system is provided with mixed liquid reflux, the end of the aerobic zone without MABR membrane treatment unit is refluxed to the front end of the second-stage MABR anoxic treatment system, and the reflux ratio is 300%, stable operation and accumulated operation data are obtained.

[0031] In the continuous operation process, the hydraulic retention time of each system is adjusted according to the water quality at any time, and the main indicators of the effluent can reach the standard of Class IV of the "Surface Water Environmental Quality Standard", wherein COD≤30 mg / L, ammonia nitrogen≤1.5 mg / L, total nitrogen≤10 mg / L and total phosphorus≤0.3 mg / L.

[0032] In the rainy season, due to the increase of rainwater, the flow of urban sewage treatment increases, and on the basis of not increasing the water treatment unit, the above-mentioned transformed water treatment process system is adjusted and operated as follows:

[0033] (1) Hydraulic retention time adjustment: the hydraulic retention time of the first-stage MABR anaerobic treatment system is 1h, the hydraulic retention time of the second-stage MABR anoxic treatment system is 5h, and the hydraulic retention time of the MABR aerobic treatment system is 8h;

[0034] (2) Dissolved oxygen content adjustment: the dissolved oxygen of the primary MABR anaerobic treatment system is 0.2 mg / L, the dissolved oxygen of the secondary MABR anoxic treatment system is 0.5 mg / L, and the dissolved oxygen of the MABR aerobic treatment system is 1.5 mg / L;

[0035] (3) Mixed liquor reflux ratio adjustment: the MABR good treatment system is provided with mixed liquor reflux, the end of the aerobic zone of the MABR membrane treatment unit is refluxed to the front end of the secondary MABR anoxic treatment system, and the reflux ratio is 100%-200%.

[0036] In the continuous operation process, the effluent water quality meets the first level A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant, wherein the main water quality indexes are COD≤50 mg / L, ammonia nitrogen≤5 mg / L, total nitrogen≤15 mg / L, and total phosphorus≤0.5 mg / L, and the treatment water volume is increased to 3.0×104 m 3 / d.

[0037] After the above process system is transformed, the effluent water quality can be improved under the condition of the same treatment water volume; when the effluent water quality is met in the rainy season, the treatment water volume can be increased by 20%.

[0038] After the transformation is completed, the sludge production is reduced due to the MABR technology, the simultaneous nitrification and denitrification is achieved, the nitrogen removal effect is good, the external carbon source addition is reduced by 90%, the gas supply equipment is not increased, the oxygen utilization rate of the MABR technology is high, the permeation oxygen is utilized, the use amount of the gas supply equipment is reduced, and the gas amount is saved by 15%.

[0039] The above examples are only for illustrating the technical concept and characteristics of the present application, the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the essence of the present application should be covered within the protection scope of the present application.

Claims

1. A wastewater treatment method and its control method using MABR coupled with MBR, characterized in that: The specific steps are as follows: (1) Constructing a primary MABR anaerobic treatment system: The MABR packing membrane treatment unit is implanted into the latter half of the original anaerobic zone. After the tank is filled with water, the water intake is stopped and the air supply system is turned on. After 24 hours of aeration, the aeration is stopped for 24 hours. The air supply system is then gradually restored and water is introduced in a gradient manner with a daily increase of 15%-20%. After 5-7 days, water is introduced at the normal flow rate. The dissolved oxygen is controlled to be less than 0.2 mg / L. Gradually, the anoxic / anaerobic biofilm structure is formed on the outer surface of the MABR membrane fibers from the inside to the outside, and the packing forms an anaerobic biofilm structure. The construction of the MABR anaerobic treatment system with anaerobic treatment and MABR anoxic treatment is completed. (2) Constructing a two-stage MABR anoxic treatment system: mainly composed of MABR membrane treatment units, flow promoters, air supply systems and monitoring systems. The MABR membrane treatment units are implanted into the original anoxic zone, which is divided into two zones to form a single-zone mixed flow. The two zones are connected in series to form a flow promoter. The flow promoter is set at the beginning of the second zone. The tank receives the effluent from the first-stage MABR anaerobic treatment system. The air supply system is turned on. After aeration for 24 hours, the aeration rate is reduced to maintain the dissolved oxygen content of the anoxic zone tank at 0.2-0.5 mg / L. After 5-7 days, the normal flow rate is introduced to gradually complete the formation of an aerobic / anoxic biofilm structure on the outer surface of the MABR membrane fibers from the inside out, degrading and removing carbon and nitrogen pollutants, and completing the construction of a MABR anoxic treatment system with anoxic as the main component and MABR aerobic treatment. (3) Constructing the MABR aerobic treatment system: It mainly consists of MABR membrane treatment units, air supply system and monitoring system. The MABR membrane treatment units are implanted at the front end of the original aerobic zone. The original aerobic zone is divided into two zones by a partition. The first half is the MABR aerobic zone and the second half maintains the original aerobic zone. The air supply system continuously supplies air. The tank receives the effluent from the secondary MABR anoxic treatment system. The air supply system is turned on and runs continuously to maintain the dissolved oxygen content of the aerobic zone tank at 0.5-1.5 mg / L. After 5-7 days, water is introduced at normal flow rate. The low aerobic biofilm structure is gradually formed on the outer surface of the MABR membrane fibers from the inside to the outside, degrading and removing carbon and nitrogen pollutants, and completing the construction of the MABR aerobic treatment system. (4) Constructing an MBR filtration and sedimentation system: mainly composed of an MBR tank, an MBR treatment unit, a pump group, an MBR aeration system, an air supply system and a monitoring system. The MBR treatment unit is located in the MBR tank, the MBR aeration system is located at the bottom of the MBR tank, the sludge in the MBR tank comes from the aerobic treatment system, and the sludge concentration is maintained at 6000 mg / L or above. (5) System operation: After the construction of each system is completed, the hydraulic retention time is adjusted, and the data of the monitoring system in each tank is fed back to the central control system. The parameters of air supply pressure, dissolved oxygen content, hydraulic retention time and MBR sludge concentration of each system are adjusted through the central control system to optimize the sewage treatment system and achieve the discharge standard. The hydraulic retention time of the primary MABR anaerobic treatment system is 1-2 hours. The hydraulic retention time of the secondary MABR anoxic treatment system is 5-8 hours. The hydraulic retention time of the MABR aerobic treatment system is 8-12 hours; the MABR membrane treatment unit fill ratio is less than 1 / 3. The MABR good treatment system is equipped with mixed liquor reflux. The end of the aerobic zone without MABR membrane treatment unit is refluxed to the front end of the secondary MABR anoxic treatment system, with a reflux ratio of 100%-300%. The gas supply system mainly includes gas supply equipment, gas supply pipelines and valves. The gas supply pipelines are connected to the MABR packing membrane treatment unit, MABR membrane treatment unit and MBR aeration system of each tank, and gas is supplied to each system through the gas supply pipelines. The monitoring system mainly monitors dissolved oxygen, temperature, gas supply pressure, chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus.

2. The wastewater treatment and control method of MABR coupled with MBR according to claim 1, characterized in that: The MABR packed membrane treatment unit mainly consists of MABR membrane modules, membrane frames, curtain packing, gas connection pipes and valves. The primary MABR anaerobic treatment system is designed with two or more MABR packed membrane treatment units.

3. The wastewater treatment and control method of MABR coupled with MBR according to claim 1, characterized in that: The MABR membrane treatment unit mainly consists of MABR membrane modules, membrane frames, gas connection pipes, and valves. The secondary MABR anoxic treatment system is designed with 4 or more MABR membrane treatment units, and the MABR aerobic treatment system is designed with 5 or more MABR membrane treatment units.